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Romano P, Duarte NJC, Junior JMDS, Junior EM, Sandre A, Rocha A, Duarte AJ, Gomez DS, Lanchote VL, Santos SRC. EFETIVIDADE DA TERAPIA ANTIMICROBIANA EM PACIENTE SÉPTICO IDOSO GRANDE QUEIMADO EM TERAPIA INTENSIVA COM VANCOMICINA‐MEROPENEM ATRAVÉS DA ABORDAGEM FARMACOCINÉTICA‐FARMACODINÂMICA. Braz J Infect Dis 2021. [DOI: 10.1016/j.bjid.2020.101403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Arroyo G, Bustos JA, Lescano AG, Gonzales I, Saavedra H, Rodriguez S, Pretell EJ, Bonato PS, Lanchote VL, Takayanagui OM, Horton J, Gonzalez AE, Gilman RH, Garcia HH. Albendazole Sulfoxide Plasma Levels and Efficacy of Antiparasitic Treatment in Patients With Parenchymal Neurocysticercosis. Clin Infect Dis 2020; 69:1996-2002. [PMID: 30715265 DOI: 10.1093/cid/ciz085] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 01/25/2019] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND The efficacy of albendazole therapy in patients with parenchymal neurocysticercosis (NCC) is suboptimal. Plasma levels of albendazole sulfoxide (ASOX), the active metabolite of albendazole, are highly variable among patients. We hypothesized that high ASOX plasma levels during albendazole therapy may be associated with an increased antiparasitic efficacy. METHODS ASOX plasma levels were measured at treatment day 7 in 118 patients with parenchymal NCC enrolled in a treatment trial. The relationships between increasing ASOX plasma levels with the proportion of cysts resolved and the proportion of patients with complete cyst resolution (evaluated by 6-month brain magnetic resonance) were assessed. RESULTS There was a trend toward a higher proportion of cysts resolved and a higher proportion of patients cured with increasing quartiles of ASOX plasma levels. In patients with 3 or more brain cysts, the regression analysis adjusted by the concomitant administration of praziquantel (PZQ) showed a 2-fold increase in the proportion of cysts resolved (risk ratio [RR], 1.98; 95% confidence interval [CI], 1.01-3.89; P = .048) and 2.5-fold increase in the proportion of patients cured (RR, 2.45; 95% CI, .94-6.36; P = .067) when ASOX levels in the highest vs the lowest quartile were compared. No association was found in patients with 1-2 brain cysts. CONCLUSIONS We suggest an association between high ASOX plasma levels and increased antiparasitic efficacy in patients with parenchymal NCC. Nonetheless, this association is also influenced by other factors including parasite burden and concomitant administration of PZQ. These findings may serve to individualize and/or adjust therapy schemes to avoid treatment failure.
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Affiliation(s)
| | - Javier A Bustos
- Department of Microbiology, School of Sciences, Lima.,Center for Global Health, Universidad Peruana Cayetano Heredia, Lima.,Cysticercosis Unit, Instituto Nacional de Ciencias Neurológicas, Lima
| | | | - Isidro Gonzales
- Cysticercosis Unit, Instituto Nacional de Ciencias Neurológicas, Lima
| | - Herbert Saavedra
- Cysticercosis Unit, Instituto Nacional de Ciencias Neurológicas, Lima
| | - Silvia Rodriguez
- Cysticercosis Unit, Instituto Nacional de Ciencias Neurológicas, Lima
| | | | - Pierina S Bonato
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, United Kingdom
| | - Vera L Lanchote
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, United Kingdom
| | - Osvaldo M Takayanagui
- Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo Brasil, United Kingdom
| | | | - Armando E Gonzalez
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Robert H Gilman
- Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
| | - Hector H Garcia
- Department of Microbiology, School of Sciences, Lima.,Center for Global Health, Universidad Peruana Cayetano Heredia, Lima.,Cysticercosis Unit, Instituto Nacional de Ciencias Neurológicas, Lima
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Ximenez JP, Lanchote VL, Bello MA, Iocken FHS, Obadia RCM, Sousa VP, Suarez‐Kurtz G. Post‐marketing assessment of generic tamoxifen in Brazilian breast cancer patients. Basic Clin Pharmacol Toxicol 2020; 126:432-436. [DOI: 10.1111/bcpt.13368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 11/19/2019] [Indexed: 11/28/2022]
Affiliation(s)
- João P. Ximenez
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto Universidade de São Paulo Ribeirão Preto Brazil
| | - Vera L. Lanchote
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto Universidade de São Paulo Ribeirão Preto Brazil
| | - Marcelo A. Bello
- Hospital do Cancer III Instituto Nacional de Câncer Rio de Janeiro Brazil
| | | | | | - Valéria P. Sousa
- Laboratório de Controle de Qualidade Faculdade de Farmácia Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil
| | - Guilherme Suarez‐Kurtz
- Coordenação de Pesquisa Instituto Nacional de Câncer and Rede Nacional de Farmacogenética Rio de Janeiro Brazil
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Godoy ALPC, de Jesus C, Gonçalves RS, Azeredo FJ, Rocha A, Marques MP, Lanchote VL, Larangeira DF, Barrouin-Melo SM. Detection of allopurinol and oxypurinol in canine urine by HPLC/MS-MS: Focus on veterinary clinical pharmacokinetics. J Pharm Biomed Anal 2020; 185:113204. [PMID: 32126445 DOI: 10.1016/j.jpba.2020.113204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/20/2020] [Accepted: 02/22/2020] [Indexed: 10/24/2022]
Abstract
Allopurinol is the most commonly used drug for the treatment of hyperuricemia in people, and in view of the risks of fatal hypersensitivity in patients with renal dysfunction, doses based on the glomerular filtration rate are proposed. In veterinary medicine, allopurinol is used in the treatment of canine leishmaniasis (CanL) caused by Leishmania infantum owing to the drug action of inhibiting the parasite's RNA synthesis. However, renal dysfunction frequently ensues from disease progression in dogs. The purpose of the present study was to standardize and validate a sensitive high-performance liquid chromatography-mass spectrometric (HPLC-MS/MS) method to determine the concentration of allopurinol and its active metabolite oxypurinol in canine urine for clinical pharmacokinetic investigation. Urine samples of eleven (11) dogs with naturally occurring CanL and in the maintenance phase of the treatment with alopurinol were used. For the chromatographic analysis of urine, the mobile phase consisted of a solution of 0.1 % formic acid (88 %) in 10 mM ammonium acetate. Separation of allopurinol and oxypurinol occurred in a flow of 0.8 mL/min on a C8 reverse phase column 5 μm, and acyclovir was the internal standard. The HPLC-MS/MS method was validated by reaching the limits of detection and quantification, reproducibility and linearity. The lower limit of quantification achieved by the method was 10 μg/mL for both allopurinol and oxypurinol. Calibration curves were prepared in blank urine added with allopurinol at concentrations of 10-1000 μg/mL, and oxypurinol at 10-200 μg/mL. Coefficients of variation of less than 15 % between intracurrent and intercurrent accuracy values were observed for both allopurinol and oxypurinol. Urine test samples remained stable after being subjected to freeze-thaw cycles and remaining at room temperature for 4 h. The method proved to be adequate to quantify allopurinol and oxypurinol in urine samples from dogs under treatment.
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Affiliation(s)
- Ana Leonor P C Godoy
- Department of Clinical and Toxicological Analysis, Faculty of Pharmacy, Federal University of Bahia (UFBA), Rua Barão de Jeremoabo, 147, Salvador, BA, 40170-115, Brazil
| | - Clauceane de Jesus
- Teaching Hospital of Veterinary Medicine, UFBA, Av. Adhemar de Barros, 500, Salvador, BA, 40170-110, Brazil
| | - Rafaela S Gonçalves
- Teaching Hospital of Veterinary Medicine, UFBA, Av. Adhemar de Barros, 500, Salvador, BA, 40170-110, Brazil
| | - Francine Johansson Azeredo
- Department of Medicines, Faculty of Pharmacy, Federal University of Bahia (UFBA), Rua Barão de Jeremoabo, 147, Salvador, BA, 40170-115, Brazil
| | - Adriana Rocha
- Department of Clinical, Toxicological and Bromatological Analyzes, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida do Café, S / N, Ribeirão Preto, SP, 14040-903, Brazil
| | - Maria P Marques
- Department of Clinical, Toxicological and Bromatological Analyzes, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida do Café, S / N, Ribeirão Preto, SP, 14040-903, Brazil
| | - Vera L Lanchote
- Department of Clinical, Toxicological and Bromatological Analyzes, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida do Café, S / N, Ribeirão Preto, SP, 14040-903, Brazil
| | - Daniela F Larangeira
- Teaching Hospital of Veterinary Medicine, UFBA, Av. Adhemar de Barros, 500, Salvador, BA, 40170-110, Brazil; Department of Veterinary Anatomy, Pathology and Clinics, School of Veterinary Medicine and Zootechny, UFBA, Salvador, BA, 40170-110, Brazil
| | - Stella Maria Barrouin-Melo
- Teaching Hospital of Veterinary Medicine, UFBA, Av. Adhemar de Barros, 500, Salvador, BA, 40170-110, Brazil; Department of Veterinary Anatomy, Pathology and Clinics, School of Veterinary Medicine and Zootechny, UFBA, Salvador, BA, 40170-110, Brazil.
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Cusinato DAC, Martinez EZ, Cintra MTC, Filgueira GCO, Berretta AA, Lanchote VL, Coelho EB. Evaluation of potential herbal-drug interactions of a standardized propolis extract (EPP-AF®) using an in vivo cocktail approach. J Ethnopharmacol 2019; 245:112174. [PMID: 31442620 DOI: 10.1016/j.jep.2019.112174] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 08/14/2019] [Accepted: 08/19/2019] [Indexed: 06/10/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Propolis has been employed extensively in many cultures since ancient times as antiseptic, wound healing, anti-pyretic and others due to its biological and pharmacological properties, such as immunomodulatory, antitumor, anti-inflammatory, antioxidant, antibacterial, antiviral, antifungal, antiparasite activities. But despite its broad and traditional use, there is little knowledge about its potential interaction with prescription drugs. AIM OF THE STUDY The main objective of this work was to study the potential herbal-drug interactions (HDIs) of EPP-AF® using an in vivo assay with a cocktail approach. MATERIALS AND METHODS Subtherapeutic doses of caffeine, losartan, omeprazole, metoprolol, midazolam and fexofenadine were used. Sixteen healthy adult volunteers were investigated before and after exposure to orally administered 125 mg/8 h (375 mg/day) EPP-AF® for 15 days. Pharmacokinetic parameters were calculated based on plasma concentration versus time (AUC) curves. RESULTS After exposure to EPP-AF®, it was observed decrease in the AUC0-∞ of fexofenadine, caffeine and losartan of approximately 18% (62.20 × 51.00 h.ng/mL), 8% (1085 × 999 h.ng/mL) and 13% (9.01 × 7.86 h.ng/mL), respectively, with all 90% CIs within the equivalence range of 0.80-1.25. On the other hand, omeprazole and midazolam exhibited an increase in AUC0-∞ of, respectively, approximately 18% (18.90 × 22.30 h.ng/mL) and 14% (1.25 × 1.43 h.ng/mL), with the upper bounds of 90% CIs slightly above 1.25. Changes in pharmacokinetics of metoprolol or its metabolite α-hydroxymetoprolol were not statistically significant and their 90% CIs were within the equivalence range of 0.80-1.25. CONCLUSIONS In conclusion, our study shows that EPP-AF® does not clinically change CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A activities, once, despite statistical significant, the magnitude of the changes in AUC values after EPP-AF® were all below 20% and therefore may be considered safe regarding potential interactions involving these enzymes. Besides, to the best of our knowledge this is the first study to assess potential HDIs with propolis.
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Affiliation(s)
- Diego A C Cusinato
- School of Pharmaceutical Sciences of Ribeirão Preto, Department of Clinical Analysis, Toxicology and Food Science, University of São Paulo, Brazil
| | - Edson Z Martinez
- Ribeirão Preto Medical School, Department of Social Medicine, University of São Paulo Ribeirão Preto, Brazil
| | - Mônica T C Cintra
- General Clinical Research Center, Teaching Hospital Ribeirão Preto, Brazil
| | - Gabriela C O Filgueira
- Medical School, University of São Paulo Medical School, Department of Obstetrics and Gynecology, University of São Paulo, Brazil
| | - Andresa A Berretta
- Laboratório de Pesquisa, Desenvolvimento & Inovação, Apis Flora Indl. Coml. Ltda., Ribeirão Preto, SP, Brazil
| | - Vera L Lanchote
- School of Pharmaceutical Sciences of Ribeirão Preto, Department of Clinical Analysis, Toxicology and Food Science, University of São Paulo, Brazil
| | - Eduardo B Coelho
- School of Pharmaceutical Sciences of Ribeirão Preto, Department of Clinical Analysis, Toxicology and Food Science, University of São Paulo, Brazil; Ribeirão Preto Medical School, Department of Internal Medicine, University of São Paulo, Brazil.
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Costa ACC, Coelho EB, Lanchote VL, Correia BV, Abumansur JT, Lauretti GR, de Moraes NV. The SLCO1A2 -189_-188InsA polymorphism reduces clearance of rocuronium in patients submitted to elective surgeries. Eur J Clin Pharmacol 2017; 73:957-963. [PMID: 28409297 DOI: 10.1007/s00228-017-2243-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 03/22/2017] [Indexed: 12/19/2022]
Abstract
PURPOSE Rocuronium (ROC) is a neuromuscular blocker mainly eliminated by biliary excretion dependent on organic anion transporting polypeptide 1A2 (OATP1A2) hepatocellular uptake. However, the influence of SLCO1A2 (gene encoding OATP1A2) genetic polymorphism on ROC pharmacokinetics was never described before. The objective of this work was to evaluate the influence of genetic polymorphisms of SLCO1A2 on the pharmacokinetics of rocuronium (ROC). METHODS Patients undergoing elective surgeries under general anesthesia using rocuronium as a neuromuscular blocker were genotyped for SLCO1A2 polymorphisms in the coding region (41A>G, 382A>T, 404A>T, 502C>T, 516A>C, 559G>A, 830C>A, and 833delA) and in the promoter region (-1105G>A, -1032G>A, -715T>C, -361G>A, and -189_-188insA). Rocuronium pharmacokinetic parameters were estimated by non-compartmental analysis. RESULTS None of the patients had heterozygous or homozygous variant of 404A>T, 382A>T, 502C>T, 833delA, 830C>A, 41A>G, and -715T>C. A linkage disequilibrium was found between -1105G>A and -1032G>A genotypes. Patients genotyped as -A or AA (n = 17) for SLCO1A2 -189_-188InsA showed reduced total clearance of ROC compared to patients genotyped as -/- (n = 13) (151.6 vs 207.1 mL/min, p ≤ 0.05). The pharmacokinetics parameters of ROC were not significantly different between other SLCO1A2 genotypes. CONCLUSION SLCO1A2 -189_-188InsA polymorphism is related to the reduced clearance of rocuronium in patients submitted to elective surgeries under general anesthesia. TRIAL REGISTRATION NCT 02399397 ( ClinicalTrials.gov ).
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Affiliation(s)
- A C C Costa
- Universidade de São Paulo (USP), Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Ribeirão Preto, SP, Brazil
| | - E B Coelho
- Universidade de São Paulo (USP), Faculdade de Medicina de Ribeirão Preto, Ribeirão Preto, SP, Brazil
| | - V L Lanchote
- Universidade de São Paulo (USP), Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Ribeirão Preto, SP, Brazil
| | - B V Correia
- Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas, Araraquara, SP, Brazil
| | - J T Abumansur
- Universidade de São Paulo (USP), Faculdade de Medicina de Ribeirão Preto, Ribeirão Preto, SP, Brazil
| | - G R Lauretti
- Universidade de São Paulo (USP), Faculdade de Medicina de Ribeirão Preto, Ribeirão Preto, SP, Brazil
| | - N V de Moraes
- Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas, Araraquara, SP, Brazil.
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Nardotto GHB, Coelho EB, Paiva CE, Lanchote VL. Effects of Type 2 Diabetes Mellitus in Patients on Treatment With Glibenclamide and Metformin on Carvedilol Enantiomers Metabolism. J Clin Pharmacol 2017; 57:760-769. [DOI: 10.1002/jcph.864] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 11/30/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Glauco H. B. Nardotto
- Faculdade de Ciências Farmacêuticas Ribeirão Preto; Universidade de São Paulo; São Paulo Brazil
| | - Eduardo B. Coelho
- Faculdade de Medicina de Ribeirão Preto; Universidade de São Paulo; São Paulo Brazil
| | - Carlos E. Paiva
- Faculdade de Medicina de Ribeirão Preto; Universidade de São Paulo; São Paulo Brazil
| | - Vera L. Lanchote
- Faculdade de Ciências Farmacêuticas Ribeirão Preto; Universidade de São Paulo; São Paulo Brazil
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Varrique RM, Lauretti GR, Matsumoto JA, Lanchote VL, de Moraes NV. Pharmacokinetics and pharmacodynamics of rocuronium in young adult and elderly patients undergoing elective surgery. J Pharm Pharmacol 2016; 68:1351-1358. [DOI: 10.1111/jphp.12617] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 07/10/2016] [Indexed: 12/20/2022]
Abstract
Abstract
Objective
To evaluate the impact of advanced age on rocuronium kinetic disposition in ASA I–III patients undergoing elective surgeries.
Methods
Young adult (20–50 years, n = 15) and elderly patients (65–85 years, n = 14) submitted to surgery under general anaesthesia were investigated. All patients were induced with individual intravenous doses of midazolam, rocuronium, fentanyl and propofol. Rocuronium-induced neuromuscular block was monitored by train of four stimulations of the adductor muscle of the thumb on the ulnar nerve. The pharmacokinetic parameters were calculated by non-compartmental analysis. The relationship between rocuronium plasma concentration and the neuromuscular blockade was described by a sigmoidal Emax model.
Key-findings
Elderly patients presented decreased Cl (2.1 ml/kg per min vs 2.8 ml/kg per min; P = 0.0123); increased AUC/dose (507.8 μg min/ml (mg/kg) vs 392.2 μg min/ml/(mg/kg); P = 0.0168) and reduced volume of distribution (285.4 ml/kg vs 435.6 ml/kg, P = 0.0434) compared to young adults. The concentrations required to achieve 50% of maximum neuromuscular block (EC50) were similar for young adult (338.8 ng/ml) and elderly (462.7 ng/ml) patients (P > 0.05).
Conclusions
Elderly patients showed increased AUC/D and reduced total Cl compared to young adult patients due to the age-related reduced renal function. Differences in the PK-PD properties of rocuronium in elderly population are due to changes in drug disposition rather than to alterations in the sensitivity to the drug.
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Affiliation(s)
- Renan M Varrique
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, USP – Univ. de São Paulo, Ribeirão Preto, Brazil
| | - Gabriela R Lauretti
- Faculdade de Medicina de Ribeirão Preto, USP – Univ. de São Paulo, Ribeirão Preto, Brazil
| | - Julia A Matsumoto
- Faculdade de Ciências Farmacêuticas, UNESP – Univ. Estadual Paulista, Araraquara, Brazil
| | - Vera L Lanchote
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, USP – Univ. de São Paulo, Ribeirão Preto, Brazil
| | - Natalia V de Moraes
- Faculdade de Ciências Farmacêuticas, UNESP – Univ. Estadual Paulista, Araraquara, Brazil
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Neves DV, Lanchote VL, Moysés Neto M, Cardeal da Costa JA, Vieira CP, Coelho EB. Influence of chronic kidney disease and haemodialysis treatment on pharmacokinetics of nebivolol enantiomers. Br J Clin Pharmacol 2016; 82:83-91. [PMID: 26914703 DOI: 10.1111/bcp.12917] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 01/19/2016] [Accepted: 02/18/2016] [Indexed: 11/29/2022] Open
Abstract
AIM The present study evaluated the pharmacodynamics and pharmacokinetics of nebivolol enantiomers in patients with chronic kidney disease (CKD) and in patients undergoing haemodialysis. METHODS Forty-three adult patients were distributed into three groups: healthy volunteers and hypertensive patients with normal kidney function (n = 22); patients with stage 3 and 4 CKD (n = 11); and patients with stage 5 CKD undergoing haemodialysis (n = 10). The subjects received a single oral dose of 10 mg racemic nebivolol. Serial blood samples were collected up to 48 h after administration of the drug and heart rate variation was measured over the same interval during the isometric handgrip test. The nebivolol enantiomers in plasma were analysed by liquid chromatography-tandem mass spectrometry. RESULTS The pharmacokinetics of nebivolol is enantioselective, with a greater plasma proportion of l-nebivolol. CKD increased the area under the concentration-time curve (AUC) of l-nebivolol (6.83 ng.h ml(-1) vs. 9.94 ng.h ml(-1) ) and d-nebivolol (4.15 ng.h ml(-1) vs. 7.30 ng.h ml(-1) ) when compared with the control group. However, the AUC values of l-nebivolol (6.41 ng.h ml(-1) ) and d-nebivolol (4.95 ng.h ml(-1) ) did not differ between the haemodialysis and control groups. The administration of a single dose of 10 mg nebivolol did not alter the heart rate variation induced by isometric exercise in the investigated patients. CONCLUSIONS Stage 3 and 4 CKD increases the plasma concentrations of both nebivolol enantiomers, while haemodialysis restores the pharmacokinetic parameters to values similar to those observed in the control group. No significant difference in heart rate variation induced by isometric exercise was observed between the investigated groups after the administration of a single oral dose of 10 mg nebivolol.
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Affiliation(s)
- Daniel V Neves
- Department of Clinical Analysis, Food Science and Toxicology, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Vera L Lanchote
- Department of Clinical Analysis, Food Science and Toxicology, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Miguel Moysés Neto
- Department of Internal Medicine, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - José A Cardeal da Costa
- Department of Internal Medicine, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Carolina P Vieira
- Department of Clinical Analysis, Food Science and Toxicology, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Eduardo B Coelho
- Department of Internal Medicine, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
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de Moraes NV, Lauretti GR, Coelho EB, Godoy ALPC, Neves DV, Lanchote VL. Impact of fraction unbound, CYP3A, and CYP2D6 in vivo activities, and other potential covariates to the clearance of tramadol enantiomers in patients with neuropathic pain. Fundam Clin Pharmacol 2015; 30:153-61. [PMID: 26947771 DOI: 10.1111/fcp.12168] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 10/15/2015] [Accepted: 11/05/2015] [Indexed: 01/04/2023]
Abstract
The pharmacokinetics of tramadol is characterized by a large interindividual variability, which is partially attributed to polymorphic CYP2D6 metabolism. The contribution of CYP3A, CYP2B6, fraction unbound, and other potential covariates remains unknown. This study aimed to investigate the contribution of in vivo activities of cytochrome P450 (CYP) 2D6 and 3A as well as other potential covariates (CYP2B6 genotype to the SNP g.15631G>T, fraction unbound, age, body weight, creatinine clearance) to the enantioselective pharmacokinetics of tramadol. Thirty patients with neuropathic pain and phenotyped as CYP2D6 extensive metabolizers were treated with a single oral dose of 100 mg tramadol. Multiple linear regressions were performed to determine the contribution of CYP activities and other potential covariates to the clearance of tramadol enantiomers. The apparent total clearances were 44.9 (19.1-102-2) L/h and 55.2 (14.8-126.0) L/h for (+)- and (-)-tramadol, respectively [data presented as median (minimum-maximum)]. Between 79 and 83% of the overall variation in apparent clearance of tramadol enantiomers was explained by fraction unbound, CYP2D6, and CYP3A in vivo activities and body weight. Fraction unbound explained 47 and 41% of the variation in clearance of (+)-tramadol and (-)-tramadol, respectively. Individually, CYP2D6 and CYP3A activities were shown to have moderate contribution on clearance of tramadol enantiomers (11-16% and 11-18%, respectively). In conclusion, factors affecting fraction unbound of drugs (such as hyperglycemia or co-administration of drugs highly bound to plasma proteins) should be monitored, because this parameter dominates the elimination of tramadol enantiomers.
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Affiliation(s)
- Natália V de Moraes
- Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, ZIP 14801-902, Araraquara, SP, Brazil
| | - Gabriela R Lauretti
- Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, ZIP 14049-900, Ribeirão Preto, SP, Brazil
| | - Eduardo B Coelho
- Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, ZIP 14049-900, Ribeirão Preto, SP, Brazil
| | - Ana Leonor P C Godoy
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, ZIP 14040-903, Ribeirão Preto, SP, Brazil
| | - Daniel V Neves
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, ZIP 14040-903, Ribeirão Preto, SP, Brazil
| | - Vera L Lanchote
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, ZIP 14040-903, Ribeirão Preto, SP, Brazil
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de Castro FA, Piana C, Simões BP, Lanchote VL, Della Pasqua O. Busulfan dosing algorithm and sampling strategy in stem cell transplantation patients. Br J Clin Pharmacol 2015; 80:618-29. [PMID: 25819742 DOI: 10.1111/bcp.12648] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 02/25/2015] [Accepted: 03/24/2015] [Indexed: 01/22/2023] Open
Abstract
AIM The aim of this investigation was to develop a model-based dosing algorithm for busulfan and identify an optimal sampling scheme for use in routine clinical practice. METHODS Clinical data from an ongoing study (n = 29) in stem cell transplantation patients were used for the purposes our analysis. A one compartment model was selected as basis for sampling optimization and subsequent evaluation of a suitable dosing algorithm. Internal and external model validation procedures were performed prior to the optimization steps using ED-optimality criteria. Using systemic exposure as parameter of interest, dosing algorithms were considered for individual patients with the scope of minimizing the deviation from target range as determined by AUC(0,6 h). RESULTS Busulfan exposure after oral administration was best predicted after the inclusion of adjusted ideal body weight and alanine transferase as covariates on clearance. Population parameter estimates were 3.98 h(-1), 48.8 l and 12.3 l h(-1) for the absorption rate constant, volume of distribution and oral clearance, respectively. Inter-occasion variability was used to describe the differences between test dose and treatment. Based on simulation scenarios, a dosing algorithm was identified, which ensures target exposure values are attained after a test dose. Moreover, our findings show that a sparse sampling scheme with five samples per patient is sufficient to characterize the pharmacokinetics of busulfan in individual patients. CONCLUSION The use of the proposed dosing algorithm in conjunction with a sparse sampling scheme may contribute to considerable improvement in the safety and efficacy profile of patients undergoing treatment for stem cell transplantation.
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Affiliation(s)
- Francine A de Castro
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Chiara Piana
- Leiden Academic Centre for Drug Research, Division of Pharmacology, Leiden University, Leiden, The Netherlands
| | - Belinda P Simões
- Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Vera L Lanchote
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - O Della Pasqua
- Leiden Academic Centre for Drug Research, Division of Pharmacology, Leiden University, Leiden, The Netherlands.,Clinical Pharmacology & Therapeutics, University College London, London, UK
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de Oliveira Baraldi C, Moisés ECD, de Jesus Ponte Carvalho TM, de Jesus Antunes N, Lanchote VL, Duarte G, Cavalli RC. Effect of type 2 diabetes mellitus on the pharmacokinetics of metformin in obese pregnant women. Clin Pharmacokinet 2013; 51:743-9. [PMID: 23018469 DOI: 10.1007/s40262-012-0008-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND AND OBJECTIVE The use of metformin throughout gestation by women with polycystic ovary syndrome (PCOS) and type 2 diabetes mellitus (T2DM) significantly reduces the number of first-trimester spontaneous abortions and the rate of occurrence of gestational diabetes and hypertensive syndromes. Metformin is taken up into renal tubular cells by organic cation transport 2 (OCT2) and eliminated unchanged into the urine. The objective of this study was to analyse the influence of T2DM on the pharmacokinetics of metformin in obese pregnant women and in a control group of non-diabetic obese pregnant women with PCOS. METHODS Eight non-diabetic obese pregnant women with PCOS and nine obese pregnant women with T2DM taking oral metformin 850 mg every 12 h were evaluated throughout gestation. Serial blood samples were collected over a 12-h period during the third trimester of pregnancy. Steady-state plasma concentrations of metformin were determined by high-performance liquid chromatography with a UV detector. The pharmacokinetic results of the two groups, reported as median and 25th and 75th percentile, were compared statistically using the Mann-Whitney test, with the level of significance set at p < 0.05. RESULTS The pharmacokinetic parameters detected for PCOS versus T2DM patients, reported as median, were, respectively: elimination half-life 3.75 versus 4.00 h; time to maximum concentration 2.00 versus 3.00 h; maximum concentration 1.42 versus 1.21 μg/mL; mean concentration 0.53 versus 0.56 μg/mL; area under the plasma concentration-time curve from time zero to 12 h 6.42 versus 6.73 μg·h/mL; apparent total oral clearance 105.39 versus 98.38 L/h; apparent volume of distribution after oral administration 550.51 versus 490.98 L; and fluctuation (maximum-minimum concentration variation) of 179.56 versus 181.73 %. No significant differences in pharmacokinetic parameters were observed between the groups. CONCLUSION T2DM in the presence of insulin use does not influence the pharmacokinetics of metformin in pregnant patients, demonstrating the absence of a need to increase the dose, and consequently does not influence the OCT2-mediated transport in pregnant women with PCOS.
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Affiliation(s)
- Cláudia de Oliveira Baraldi
- Department of Gynecology and Obstetrics, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Av Bandeirantes 3900, Campus da USP, CEP 14049-900, Ribeirão Preto, Brazil
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Garcia HH, Lescano AG, Lanchote VL, Pretell EJ, Gonzales I, Bustos JA, Takayanagui OM, Bonato PS, Horton J, Saavedra H, Gonzalez AE, Gilman RH. Pharmacokinetics of combined treatment with praziquantel and albendazole in neurocysticercosis. Br J Clin Pharmacol 2011; 72:77-84. [PMID: 21332573 DOI: 10.1111/j.1365-2125.2011.03945.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
AIMS Neurocysticercosis is the most common cause of acquired epilepsy in the world. Antiparasitic treatment of viable brain cysts is of clinical benefit, but current antiparasitic regimes provide incomplete parasiticidal efficacy. Combined use of two antiparasitic drugs may improve clearance of brain parasites. Albendazole (ABZ) has been used together with praziquantel (PZQ) before for geohelminths, echinococcosis and cysticercosis, but their combined use is not yet formally recommended and only scarce, discrepant data exist on their pharmacokinetics when given together. We assessed the pharmacokinetics of their combined use for the treatment of neurocysticercosis. METHODS A randomized, double-blind, placebo-controlled phase II evaluation of the pharmacokinetics of ABZ and PZQ in 32 patients with neurocysticercosis was carried out. Patients received their usual concomitant medications including an antiepileptic drug, dexamethasone, and ranitidine. Randomization was stratified by antiepileptic drug (phenytoin or carbamazepine). Subjects had sequential blood samples taken after the first dose of antiparasitic drugs and again after 9 days of treatment, and were followed for 3 months after dosing. RESULTS Twenty-one men and 11 women, aged 16 to 55 (mean age 28) years were included. Albendazole sulfoxide concentrations were increased in the combination group compared with the ABZ alone group, both in patients taking phenytoin and patients taking carbamazepine. PZQ concentrations were also increased by the end of therapy. There were no significant side effects in this study group. CONCLUSIONS Combined ABZ + PZQ is associated with increased albendazole sulfoxide plasma concentrations. These increased concentrations could independently contribute to increased cysticidal efficacy by themselves or in addition to a possible synergistic effect.
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Affiliation(s)
- Hector H Garcia
- Cysticercosis Unit, Department of Transmissible Diseases, Instituto Nacional de Ciencias Neurologicas, Jr. Ancash 1271, Barrios Altos, Lima.
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Rocha A, Coelho EB, Sampaio SA, Lanchote VL. Omeprazole preferentially inhibits the metabolism of (+)-(S)-citalopram in healthy volunteers. Br J Clin Pharmacol 2011; 70:43-51. [PMID: 20642546 DOI: 10.1111/j.1365-2125.2010.03649.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT Citalopram (CITA) pharmacokinetics are enantioselective in healthy volunteers and the metabolism of (+)-(S)-CITA to (+)-(S)-DCITA is dependent on CYP2C19. Omeprazole is a potent CYP2C19 inhibitor. WHAT THIS STUDY ADDS This study indicates that omeprazole induces a loss of enantioselectivity in the CITA pharmacokinetics because of the selective inhibition of (+)-(S)-CITA metabolism. AIM The study assessed the influence of omeprazole on the kinetic disposition of the (+)-(S)-citalopram (CITA) and (-)-(R)-CITA enantiomers in healthy volunteers. METHODS In a cross-over study, healthy volunteers (n = 9) phenotyped as extensive metabolizers of CYP2C19 and CYP2D6 and with an oral midazolam clearance ranging from 10.9 to 149.3 ml min(-1) kg(-1) received a single dose of racemic CITA (20 mg orally) in combination or not with omeprazole (20 mg day(-1) for 18 days). Serial blood samples were collected up to 240 h after CITA administration. CITA and demethylcitalopram (DCITA) enantiomers were analyzed by LC-MS/MS using a Chiralcel OD-R column. RESULTS The kinetic disposition of CITA was enantioselective in the absence of treatment with omeprazole, with the observation of a greater proportion of plasma (-)-(R)-CITA [AUC S:R ratio of 0.53 (95% CI 0.41, 0.66) for CITA and 1.08 (95% CI 0.80, 1.76) for DCITA] than (+)-(S)-CITA. Racemic CITA administration to healthy volunteers in combination with omeprazole showed a loss of enantioselectivity in CITA pharmacokinetics with an increase of approximately 120% in plasma (+)-(S)-CITA concentrations [AUC S:R ratio of 0.95 (95% CI 0.72, 1.10) for CITA and 0.95 (95% CI 0.44, 1.72) for DCITA]. CONCLUSIONS The administration of multiple doses of omeprazole preferentially inhibited (+)-(S)-CITA metabolism in healthy volunteers. Although omeprazole increased plasma concentrations of (+)-(S)-CITA by approximately 120%, it is difficult to evaluate the clinical outcome because the range of plasma CITA concentrations related to maximum efficacy and minimum risk of adverse effects has not been established.
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Affiliation(s)
- Adriana Rocha
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto-Universidade de São Paulo, Ribeirão Preto, SP, Brazil
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Mateus FH, Lepera JS, Marques MP, Boralli VB, Lanchote VL. Influence of N-hexane inhalation on the enantioselective pharmacokinetics and metabolism of verapamil in rats. Chirality 2010; 22:29-34. [PMID: 19229957 DOI: 10.1002/chir.20700] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Verapamil (VER) is commercialized as a racemic mixture of the (+)-(R)-VER and (-)-(S)-VER enantiomers. VER is biotransformed into norverapamil (NOR) and other metabolites through CYP-dependent pathways. N-hexane is a solvent that can alter the metabolism of CYP-dependent drugs. The present study investigated the influence of n-hexane (nose-only inhalation exposure chamber at concentrations of 88, 176, and 352 mg/m3) on the kinetic disposition of the (+)-(R)-VER, (-)-(S)-VER, (R)-NOR and (S)-NOR in rats treated with a single dose of racemic VER (10 mg/kg). VER and NOR enantiomers in rat plasma was analyzed by LC-MS/MS (m/z = 441.3 > 165.5 for the NOR and m/z 455.3 > 165.5 for the VER enantiomers) using a Chiralpak AD column. Pharmacokinetic analysis was performed using a monocompartmental model. The pharmacokinetics of VER was enantioselective in control rats, with higher plasma proportions of the (-)-(S)-VER eutomer (AUC(0-infinity) = 250.8 vs. 120.4 ng/ml/h; P < or = 0.05, Wilcoxon test). The (S)-NOR metabolite was also found to accumulate in plasma of control animals, with an S/R AUC(0-infinity) ratio of 1.5. The pharmacokinetic parameters AUC(0-infinity), Cl/F, Vd/F, and t(1/2) obtained for VER and NOR enantiomers were not altered by nose-only exposure to n-hexane at concentrations of 88, 176, or 352 mg/m3 (P > 0.05, Kruskal-Wallis test). However, the verapamil kinetic disposition was not enantioselective for the animals exposed to n-hexane at concentrations equal to or higher than the TLV-TWA. This finding is relevant considering that the (-)-(S)-VER eutomer is 10-20 times more potent than R-(+)-VER in terms of its chronotropic effect on atrioventricular conduction in rats and humans.
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Affiliation(s)
- Fabiano H Mateus
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
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Rocha A, Coelho EB, Lanchote VL. Influence of quinidine, fluvoxamine, and ketoconazole on the enantioselective pharmacokinetics of citalopram in rats. Can J Physiol Pharmacol 2008; 86:770-6. [DOI: 10.1139/y08-088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Citalopram (CITA) is available as a racemic mixture or as (+)-(S)-CITA. In humans, CITA is metabolized to demethylcitalopram (DCITA) by CYP2C19, CYP2D6, and CYP3A and to didemethylcitalopram by CYP2D6. There are no data regarding the enzymes involved in CITA and DCITA metabolism in rats. The present study investigated the influence of CYP inhibitors on the enantioselective metabolism of CITA in rats. Male Wistar rats (n = 6) received a single dose of 20 mg·kg–1 CITA after pretreatment with 80 mg·kg–1 quinidine, 10 mg·kg–1 fluvoxamine, 50 mg·kg–1 ketoconazole, or vehicle (control). Blood samples were collected up to 20 h after CITA administration. The CITA and DCITA enantiomers were analyzed by LC-MS/MS using a Chiralcel OD-R column. The kinetic disposition of CITA was enantioselective in rats (AUCS/R ratio = 0.4). Coadministration with quinidine resulted in non-enantioselective inhibition of the metabolism of CITA. Coadministration with fluvoxamine or ketoconazole, however, inhibited only the metabolism of (+)-(S)-CITA, but not of (–)-(R)-CITA when the racemic drug was administered to rats.
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Affiliation(s)
- Adriana Rocha
- Department of Clinical, Toxicologic and Bromatologic Analyses, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
- Department of Internal Medicine, Discipline of Nephrology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Eduardo B. Coelho
- Department of Clinical, Toxicologic and Bromatologic Analyses, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
- Department of Internal Medicine, Discipline of Nephrology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Vera L. Lanchote
- Department of Clinical, Toxicologic and Bromatologic Analyses, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
- Department of Internal Medicine, Discipline of Nephrology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
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Peccinini RG, Ximenes VF, Cesarino EJ, Lanchote VL. Stereoselective analysis of carvedilol in human plasma and urine using HPLC after chiral derivatization. Biopharm Drug Dispos 2008; 29:280-8. [DOI: 10.1002/bdd.613] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Rocha A, Coelho EB, Moussa SAP, Lanchote VL. Investigation of the in vivo activity of CYP3A in Brazilian volunteers: comparison of midazolam and omeprazole as drug markers. Eur J Clin Pharmacol 2008; 64:901-6. [PMID: 18581106 DOI: 10.1007/s00228-008-0510-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Accepted: 05/15/2008] [Indexed: 01/22/2023]
Abstract
OBJECTIVE This study compares midazolam with omeprazole as marker drugs for the evaluation of CYP3A activity in nine healthy self-reported white Brazilian volunteers. METHODS Omeprazole was also used to evaluate the CYP2C19 phenotype. The volunteers received p.o. 20 mg omeprazole, and blood samples were collected 3.5 h after drug administration. After a washout period of 10 days, the volunteers received p.o. 15 mg midazolam maleate, and serial blood samples were collected up to 6 h after administration of the drug. CYP2C19 was genotyped for the allelic variants CYP2C19*1, CYP2C19*2, CYP2C19*3, and CYP2C19*17. Analysis of omeprazole, hydroxyomeprazole, omeprazole sulfone, and midazolam in plasma was carried out by LC-MS/MS. RESULTS The volunteers genotyped as CYP2C19*1*17, CYP2C19*17*17, CYP2C19*1*1 (n = 8), or CYP2C19*17*2 (n = 1) presented a median hydroxylation index (omeprazole/hydroxyomeprazole) of 1.35, indicating that all of them were extensive metabolizers of CYP2C19. The volunteers (n = 9) presented a 0.12 log of the omeprazole/sulfone ratio and a median oral clearance of midazolam of 17.89 ml min(-1) kg(-1), suggesting normal CYP3A activity. CONCLUSIONS Orthogonal regression analysis between midazolam clearance and log of the plasma concentrations of the omeprazole/omeprazole sulfone ratio (R = -0.7544, P < 0.05) suggests that both midazolam and omeprazole can be used as markers of CYP3A activity in the population investigated.
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Affiliation(s)
- Adriana Rocha
- Departamento de Análises Clínicas, Toxicológicas and Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
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Mateus FH, Lepera JS, Marques MP, Boralli VB, Lanchote VL. Reduction of enantioselectivity in the kinetic disposition and metabolism of verapamil in rats exposed to toluene. Can J Physiol Pharmacol 2008; 86:232-9. [PMID: 18432283 DOI: 10.1139/y08-017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Toluene and verapamil are subject to extensive oxidative metabolism mediated by CYP enzymes, and their interaction can be stereoselective. In the present study we investigated the influence of toluene inhalation on the enantioselective kinetic disposition of verapamil and its metabolite, norverapamil, in rats. Male Wistar rats (n = 6 per group) received a single dose of racemic verapamil (10 mg/kg) orally at the fifth day of nose-only toluene or air (control group) inhalation for 6 h/day (25, 50, and 100 ppm). Serial blood samples were collected from the tail up to 6 h after verapamil administration. The plasma concentrations of verapamil and norverapamil enantiomers were analyzed by LC-MS/MS by using a Chiralpak AD column. Toluene inhalation did not influence the kinetic disposition of verapamil or norverapamil enantiomers (p > 0.05, Kruskal-Wallis test) in rats. The pharmacokinetics of verapamil was enantioselective in the control group, with a higher plasma proportion of the S-verapamil (AUC 250.8 versus 120.4 ng x h x mL(-1); p < or = 0.05, Wilcoxon test) and S-norverapamil (AUC 72.3 versus 52.3 ng x h x mL(-1); p < or = 0.05, Wilcoxon test). Nose-only exposure to toluene at 25, 50, or 100 ppm resulted in a lack of enantioselectivity for both verapamil and norverapamil. The study demonstrates the importance of the application of enantioselective methods in studies on the interaction between solvents and chiral drugs.
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Affiliation(s)
- F H Mateus
- Departamento de Analises Clinicas, Toxicologicas e Bromatologicas, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Universidade de Sao Paulo, Brazil
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Tirapelli CR, Legros E, Brochu I, Honoré JC, Lanchote VL, Uyemura SA, de Oliveira AM, D'Orléans-Juste P. Chronic ethanol intake modulates vascular levels of endothelin-1 receptor and enhances the pressor response to endothelin-1 in anaesthetized rats. Br J Pharmacol 2008; 154:971-81. [PMID: 18469849 DOI: 10.1038/bjp.2008.157] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND AND PURPOSE The contribution of endothelin-1 (ET-1) to vascular hyper-reactivity associated with chronic ethanol intake, a major risk factor in several cardiovascular diseases, remains to be investigated. EXPERIMENTAL APPROACH The biphasic haemodynamic responses to ET-1 (0.01-0.1 nmol kg(-1), i.v.) or to the selective ETB agonist, IRL1620 (0.001-1.0 nmol kg(-1), i.v.), with or without ETA or ETB antagonists (BQ123 (c(DTrp-Dasp-Pro-Dval-Leu)) at 1 and 2.5 mg kg(-1) and BQ788 (N-cis-2,6-dimethyl-piperidinocarbonyl-L-gamma-methylleucyl1-D-1methoxycarbonyltryptophanyl-D-norleucine) at 0.25 mg kg(-1), respectively) were tested in anaesthetized rats, after 2 weeks' chronic ethanol treatment. Hepatic parameters and ET receptor protein levels were also determined. KEY RESULTS The initial hypotensive responses to ET-1 or IRL1620 were unaffected by chronic ethanol intake, whereas the subsequent pressor effects induced by ET-1, but not by IRL1620, were potentiated. BQ123 at 2.5 but not 1 mg kg(-1) reduced the pressor responses to ET-1 in ethanol-treated rats. Conversely, BQ788 (0.25 mg kg(-1)) potentiated ET-1-induced increases in mean arterial blood pressure in control as well as in ethanol-treated rats. Interestingly, in the latter group, increases in heart rate, induced by ET-1 at a dose of 0.025 mg kg(-1) were enhanced following ETB receptor blockade. Finally, we observed higher levels of ETA receptor in the heart and mesenteric artery and a reduction of ETB receptor protein levels in the aorta and kidney from rats chronically treated with ethanol. CONCLUSIONS AND IMPLICATIONS Increased vascular reactivity to ET-1 and altered protein levels of ETA and ETB receptors could play a role in the pathogenesis of cardiovascular complications associated with chronic ethanol consumption.
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Affiliation(s)
- C R Tirapelli
- Department of Pharmacology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
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Tirapelli CR, Leone AFC, Yogi A, Tostes RC, Lanchote VL, Uyemura SA, Resstel LBM, Corrêa FMA, Padovan CM, de Oliveira AM, Coelho EB. Ethanol consumption increases blood pressure and alters the responsiveness of the mesenteric vasculature in rats. J Pharm Pharmacol 2008; 60:331-41. [PMID: 18284813 DOI: 10.1211/jpp.60.3.0008] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Chronic ethanol consumption and hypertension are related. In the current study we investigated whether changes in reactivity of the mesenteric arterial bed could account for the increased blood pressure associated with chronic ethanol intake. Changes in reactivity to phenylephrine and acetylcholine were investigated in the perfused mesenteric bed from rats treated with ethanol for 2 or 6 weeks and their age-matched controls. Mild hypertension was observed in chronically ethanol-treated rats. Treatment of rats for 6 weeks induced an increase in the contractile response of endothelium-intact mesenteric bed to phenylephrine, but not denuded rat mesenteric bed. The phenylephrine-induced increase in perfusion pressure was not altered after 2 weeks' treatment with ethanol. Moreover, acetylcholine-induced endothelium-dependent relaxation was reduced by ethanol treatment for 6 weeks, but not 2 weeks. Pre-treatment with indometacin, a cyclooxygenase inhibitor, reduced the maximum effect induced by phenylephrine (Emax) in endothelium-intact mesenteric bed from both control and ethanol-treated rats. No differences in the Emax values for phenylephrine were observed between groups in the presence of indometacin. L-NNA, a nitric oxide (NO) synthase (NOS) inhibitor, increased the Emax for phenylephrine in endothelium-intact mesenteric bed from control rats but not from ethanol-treated rats. Levels of endothelial NOS (eNOS) mRNA were not altered by chronic ethanol consumption. However, chronic ethanol intake strongly reduced eNOS protein levels in the mesenteric bed. This study shows that chronic ethanol consumption increases blood pressure and alters the reactivity of the mesenteric bed. Moreover, the increased vascular response to phenylephrine observed in the mesenteric bed is maintained by two mechanisms: an increased release of endothelial-derived vasoconstrictor prostanoids and a reduced modulatory action of endothelial NO, which seems to be associated with reduced post-transcriptional expression of eNOS.
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Affiliation(s)
- Carlos R Tirapelli
- Department of Psychiatric Nursing and Human Sciences, College of Nursing of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
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Tirapelli CR, Fukada SY, Yogi A, Chignalia AZ, Tostes RC, Bonaventura D, Lanchote VL, Cunha FQ, de Oliveira AM. Gender-specific vascular effects elicited by chronic ethanol consumption in rats: a role for inducible nitric oxide synthase. Br J Pharmacol 2007; 153:468-79. [PMID: 18037914 DOI: 10.1038/sj.bjp.0707589] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND AND PURPOSE Epidemiological data suggest that the risk of ethanol-associated cardiovascular disease is greater in men than in women. This study investigates the mechanisms underlying gender-specific vascular effects elicited by chronic ethanol consumption in rats. EXPERIMENTAL APPROACH Vascular reactivity experiments using standard muscle bath procedures were performed on isolated thoracic aortae from rats. mRNA and protein for inducible NO synthase (iNOS) and for endothelial NOS (eNOS) was assessed by RT-PCR or western blotting, respectively. KEY RESULTS In male rats, chronic ethanol consumption enhanced phenylephrine-induced contraction in both endothelium-intact and denuded aortic rings. However, in female rats, chronic ethanol consumption enhanced phenylephrine-induced contraction only in endothelium denuded aortic rings. After pre-incubation of endothelium-intact rings with L-NAME, both male and female ethanol-treated rats showed larger phenylephrine-induced contractions in aortic rings, compared to the control group. Acetylcholine-induced relaxation was not affected by ethanol consumption. The effects of ethanol on responses to phenylephrine were similar in ovariectomized (OVX) and intact (non-OVX) female rats. In the presence of aminoguanidine, but not 7-nitroindazole, the contractions to phenylephrine in rings from ethanol-treated female rats were greater than that found in control tissues in the presence of the inhibitors. mRNA levels for eNOS and iNOS were not altered by ethanol consumption. Ethanol intake reduced eNOS protein levels and increased iNOS protein levels in aorta from female rats. CONCLUSIONS AND IMPLICATIONS Gender differences in the vascular effects elicited by chronic ethanol consumption were not related to ovarian hormones but seemed to involve the upregulation of iNOS.
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Affiliation(s)
- C R Tirapelli
- Department of Psychiatry Nursing and Human Sciences, College of Nursing of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
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Rocha A, Marques MP, Coelho EB, Lanchote VL. Enantioselective analysis of citalopram and demethylcitalopram in human and rat plasma by chiral LC-MS/MS: application to pharmacokinetics. Chirality 2007; 19:793-801. [PMID: 17722014 DOI: 10.1002/chir.20452] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Citalopram (CITA) is available as a racemic mixture and as a pure enantiomer. Its antidepressive action is related to the (+)-(S)-CITA and to the metabolite (+)-(S)-demethylcitalopram (DCITA). In the present investigation, a method for the analysis of CITA and DCITA enantiomers in human and rat plasma was developed and applied to the study of pharmacokinetics. Plasma samples (1 ml) were extracted at pH 9.0 with toluene:isoamyl alcohol (9:1, v/v). The CITA and DCITA enantiomers were analyzed by LC-MS/MS on a Chiralcel OD-R column. Recovery was higher than 70% for both enantiomers. The quantification limit was 0.1 ng/ml, and linearity was observed up to 500 ng/ml plasma for each CITA and DCITA enantiomer. The method was applied to the study of the kinetic disposition of CITA administered in a single oral dose of 20 mg to a healthy volunteer and in a single dose of 20 mg/kg (by gavage) to Wistar rats (n = 6 for each time). The results showed a higher proportion of the (-)-(R)-CITA in human and rat plasma, with S/R AUC ratios for CITA of 0.28 and 0.44, respectively. S/R AUC ratios of DCITA were 0.48 for rats and 1.04 for the healthy volunteer.
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Affiliation(s)
- Adriana Rocha
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Análises Clínicas, Toxicológicas e Bromatológicaas, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
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Tirapelli CR, Leone AFC, Coelho EB, Resstel LBM, Corrêa FMA, Lanchote VL, Uyemura SA, Padovan CM, de Oliveira AM. Effect of ethanol consumption on blood pressure and rat mesenteric arterial bed, aorta and carotid responsiveness. J Pharm Pharmacol 2007; 59:985-93. [PMID: 17637194 DOI: 10.1211/jpp.59.7.0011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This study investigates whether chronic ethanol consumption increases blood pressure and alters vascular reactivity in different tissues. Changes in reactivity to phenylephrine and acetylcholine were investigated in the aorta, carotid artery and mesenteric arterial bed (MAB) isolated from rats pretreated with ethanol for 2 or 6 weeks. Mild hypertension was observed in chronically ethanol-treated rats, which was due to rises in both systolic and diastolic pressures. Chronic ethanol consumption increased the contractile response to phenylephrine of endothelium-intact and denuded rat aortic rings from rats pretreated with ethanol for 2 or 6 weeks. Conversely, no differences were found in acetylcholine-induced relaxation. Neither phenylephrine-induced contraction nor acetylcholine-induced relaxation were altered in the rat carotid. Six weeks' ethanol consumption enhanced the contractile response to phenylephrine of endothelium-intact, but not denuded rat MAB. On the other hand, 2 weeks' ethanol consumption did not affect phenylephrine-induced increase in perfusion pressure. Moreover, acetylcholine-induced endothelium-dependent relaxation in the MAB was reduced after treatment with ethanol for 6 weeks but not after 2 weeks. In conclusion, ethanol affects both blood pressure and vessel reactivity, but the effect on vascular reactivity may take longer to become apparent in MAB than in the aorta, and was not evident in the carotid. Moreover, we provide evidence that the effect of ethanol depends on the agonist and blood vessel studied.
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Affiliation(s)
- Carlos R Tirapelli
- Department of Psychiatry Nursing and Human Sciences, College of Nursing of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil.
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Tirapelli CR, Casolari DA, Yogi A, Tostes RC, Legros E, Lanchote VL, Uyemura SA, de Oliveira AM. Effect of chronic ethanol consumption on endothelin-1 generation and conversion of exogenous big-endothelin-1 by the rat carotid artery. Alcohol 2007; 41:77-85. [PMID: 17466482 DOI: 10.1016/j.alcohol.2007.02.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2006] [Revised: 01/16/2007] [Accepted: 02/09/2007] [Indexed: 12/27/2022]
Abstract
The purpose of the present work was to investigate whether conversion of exogenous applied big-endothelin-1 (Big-ET-1) as well as the basal release and mRNA levels of endothelin-1 (ET-1) is altered by ethanol consumption in the rat carotid. The measurement of the contraction induced by Big-ET-1 served as an indicative of functional endothelin (ET)-converting enzyme (ECE) activity. Cumulative application of exogenous Big-ET-1 elicited a concentration-related contraction with the concentration-response curve shifted to the right when compared to ET-1. In endothelium-intact rings, phosphoramidon (1 mmol/l), a nonselective ECE/neutral endopeptidase (NEP) inhibitor, produced a rightward displacement of the concentration-response curves and reduced the maximal contractile response to Big-ET-1. However, in endothelium-denuded rings phosphoramidon reduced the maximum contraction for Big-ET-1 but did not alter the potency when compared to the curves obtained in the absence of the inhibitor. Ethanol consumption for 2, 6, or 10 weeks reduced the contractile effect elicited by Big-ET-1 in carotid rings with intact endothelium when compared to control or isocaloric rings. However, no differences on Big-ET-1-induced contraction were observed after endothelial denudation. On the other hand, ethanol consumption increased ET-1-induced contraction. Finally, chronic ethanol consumption did not alter either the mRNA levels for pre-pro-ET-1 nor the basal release of ET-1. The present findings show that chronic ethanol consumption does not alter the mRNA levels for ET-1 or its basal release in the rat carotid. Moreover, ethanol intake reduces the contraction induced by exogenously applied Big-ET-1 in carotid rings with intact endothelium, a fact that might be the result of a reduced conversion of this peptide by ECE on its mature active peptide ET-1.
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Affiliation(s)
- Carlos R Tirapelli
- Department of Psychiatry Nursing and Human Sciences, College of Nursing of Ribeirão Preto, University of São Paulo (USP), SP, Brazil
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Tirapelli CR, Casolari DA, Montezano AC, Yogi A, Tostes RC, Legros E, D'Orléans-Juste P, Lanchote VL, Uyemura SA, de Oliveira AM. Ethanol consumption enhances endothelin-1-induced contraction in the isolated rat carotid. J Pharmacol Exp Ther 2006; 318:819-27. [PMID: 16651399 DOI: 10.1124/jpet.106.103010] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
We investigated the mechanisms involved in the enhancement of endothelin (ET)-1 vascular reactivity induced by ethanol consumption. Ethanol intake for 2, 6, and 10 weeks enhanced the ET-1-induced contractile response of endothelium-intact but not endothelium-denuded rat carotid rings independently of the treatment duration. Conversely, phenylephrine-induced contraction was not affected by ethanol intake. The contraction induced by IRL1620 [succinyl-(Glu(9),Ala(11,15))-ET-1-(8-21)], a selective ET(B) agonist, was increased after treatment with ethanol in endothelium-intact but not in endothelium-denuded carotid rings. Moreover, ET-1- and IRL1620-induced relaxation was reduced in endothelium-intact phenylephrine-precontracted rings from ethanol-treated rats. Acetylcholine-induced relaxation was not affected by ethanol treatment. N(G)-Nitro-l-arginine methyl ester, 1H-[1,2,4]-oxadiazolo[4,3-a]quinoxalin-1-one, indomethacin, and tetraethylammonium reduced the relaxation induced by IRL1620 in carotid glands from control but not ethanol-treated rats. The mRNA levels for ET(A) and ET(B) receptors were not altered by ethanol consumption. However, ethanol treatment reduced the protein expression of ET(B) receptors. Furthermore, immunohistochemical assays showed reduced immunostaining for endothelial ET(B) receptors after treatment with ethanol. We conclude that ethanol consumption enhances ET-1-induced contraction in the rat carotid and that this response is not different among the three periods of treatment used in this study. Finally, the potentiation of ET-1-induced vascular reactivity is probably caused by reduced expression of relaxing endothelial ET(B) receptors.
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Affiliation(s)
- Carlos R Tirapelli
- Department of Pharmacology, Faculty of Medicine of Ribeirão Preto, University of Sao Paulo, Sao Paulo, Sao Paulo, Brazil
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Resstel LBM, Tirapelli CR, Lanchote VL, Uyemura SA, de Oliveira AM, Corrêa FMA. Chronic ethanol consumption alters cardiovascular functions in conscious rats. Life Sci 2005; 78:2179-87. [PMID: 16288925 DOI: 10.1016/j.lfs.2005.09.021] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2005] [Accepted: 09/06/2005] [Indexed: 01/02/2023]
Abstract
Chronic ethanol intake and hypertension are related. In the present work, we investigated the effect of chronic ethanol (20% v/v) intake for 2, 6 and 10 weeks on basal arterial blood pressure, baroreflex and heart rate levels, as well as on the cardiovascular responses to the infusion of vasoactive agents in unanesthetized rats. Mild hypertension was observed after 2 weeks, 6 weeks or 10 weeks of treatment. On the other hand, no changes were observed in heart rate after long-term ethanol intake. Similar baroreflex changes were observed in 2- or 6-week ethanol-treated rats, and affected all parameters of baroreflex sigmoid curves, when compared to the control group. These changes were characterized by an enhanced baroreflex sympathetic component and a reduction in the baroreflex parasympathetic component. No differences in baroreflex parameters were observed in 10-week ethanol-treated animals. The pressor effects of i.v. phenylephrine were enhanced in 2-week ethanol-treated rats; not affected in 6-week treated animals and reduced in 10-week ethanol-treated rats, when compared to respective control and isocaloric groups. The hypotensive response to i.v. sodium nitroprusside (SNP) was enhanced at all different times of treatment, when compared to respective control and isocaloric groups. In conclusion, the present findings showed increased arterial pressure in the early phase of chronic ethanol consumption, which was consequent of rise in both systolic and diastolic pressures. Ethanol intake affected both the sympathetic and the parasympathetic components of the baroreflex. Vascular responsiveness to the pressor agent phenylephrine was initially enhanced and later on decreased during chronic ethanol intake. Vascular responsiveness to the depressor agent SNP was enhanced during chronic ethanol intake.
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Affiliation(s)
- Leonardo B M Resstel
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, Brazil
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Jabor VAP, Coelho EB, Dos Santos NAG, Bonato PS, Lanchote VL. A highly sensitive LC-MS-MS assay for analysis of midazolam and its major metabolite in human plasma: applications to drug metabolism. J Chromatogr B Analyt Technol Biomed Life Sci 2005; 822:27-32. [PMID: 15993663 DOI: 10.1016/j.jchromb.2005.05.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2004] [Revised: 04/29/2005] [Accepted: 05/17/2005] [Indexed: 12/18/2022]
Abstract
The present report describes a rapid, selective and a highly sensitive assay for midazolam (MDZ) and its major metabolite 1-hydroxymidazolam (1-OH-MDZ) in human plasma employing liquid chromatography-tandem mass spectrometry (LC-MS-MS) detection. The method involves liquid-liquid extraction sample clean-up, separation on a Purospher RP 18-e column and detection with an electrospray interface in the positive ion mode. The overall recoveries were about 100% and 80% for midazolam and 1-hydroxymidazolam, respectively. Accuracy, precision and linearity were acceptable for biological samples with quantitation limits of 0.1-100 ng mL(-1) plasma for both analytes. The validated method was successfully applied to quantify plasma concentration of midazolam and 1-hydroxymidazolam in authentic samples from a healthy volunteer following a single 15 mg oral dose of midazolam (apparent total clearance: 3.47 L h(-1)kg(-1) and AUC(0-alpha)IOH-MDZ/MDZ: 0.338).
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Affiliation(s)
- Valquiria A P Jabor
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências, Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo 14040-903, Brazil
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Tirapelli CR, Al-Khoury J, Bkaily G, D'Orléans-Juste P, Lanchote VL, Uyemura SA, de Oliveira AM. Chronic ethanol consumption enhances phenylephrine-induced contraction in the isolated rat aorta. J Pharmacol Exp Ther 2005; 316:233-41. [PMID: 16174792 DOI: 10.1124/jpet.105.092999] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Changes in reactivity to phenylephrine in aortas isolated from 2-, 6-, and 10-week ethanol-treated rats and their age-matched control and isocaloric rats were investigated. Chronic ethanol consumption enhances the contractile response of endothelium-intact and -denuded rat aortic rings to phenylephrine, a response that is time-independent. Pretreatment with indomethacin reduced E(max) for phenylephrine in denuded aortas from ethanol-treated rats but not control or isocaloric rats. After indomethacin treatment, no differences in E(max) from phenylephrine were observed among the groups. SQ29548 ([1S-[1alpha-2alpha(Z)3alpha,4alpha]]-7-[3-[[(phenylamino)carbonyl]hydrazino]methyl]-7-oxabicyclo[2.2.1]hept-2-yl]-5-heptenoic acid), an antagonist of prostaglandin H(2)/thromboxane A(2) (TXA(2)) receptors, did not alter phenylephrine-induced contraction in control or isocaloric aortas. However, in ethanol-treated aortas, E(max) was reduced to control level. Moreover, phenylephrine-stimulated release of thromboxane B(2), a stable metabolite of TXA(2), was higher in tissues from ethanol-treated rats. Simultaneous measurement of the changes in [Ca(2+)](i) and contraction induced by phenylephrine showed that both parameters are higher in the rat aorta from ethanol-treated rats. CaCl(2)-induced contraction in free Ca(2+) solution containing phenylephrine was increased in ethanol-treated aortas. Additionally, the enhancement in CaCl(2)-induced contraction was prevented by SQ29548. The major contribution of the present study is that it demonstrates a detailed description of the mechanisms involved in the enhancement of phenylephrine-induced contraction in rat aorta from ethanol-treated rats. We provided evidence that this response was not different among the three periods of treatment employed in this study and that it is maintained by two mechanisms: an increased release of vascular smooth muscle-derived vasoconstrictor prostanoids (probably TXA(2)) and an enhanced extracellular Ca(2+) influx.
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Affiliation(s)
- Carlos R Tirapelli
- Universidade de São Paulo, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Avenida do Café s/n, CEP 14040-903, Ribeirão Preto, SP, Brazil
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Cerdeira AL, dos Santos NAG, Pessoa MCPY, Gomes MAF, Lanchote VL. Herbicide leaching on a recharge area of the Guarany aquifer in Brazil. J Environ Sci Health B 2005; 40:159-165. [PMID: 15656174 DOI: 10.1081/pfc-200034294] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The region of Ribeirão Preto City, located in Southeast of Brazil, São Paulo State, is an important sugarcane, soybean, and corn producing area with a high level of pesticides utilization. This region is also an important recharge area for groundwater supply of the Guarany aquifer. Since the past ten years atrazine, simazine, ametryn, tebuthiuron, diuron, 2,4-D, picloram, and hexazinone are the main herbicides used in this area. In order to study a possible leaching of some of these herbicides into the aquifer, surface, and groundwater samples were collected in a watershed during the years of 1996 to 2003, from different locations. To detect and quantify the herbicides a GC-MS (gas chromatograph/mass spectrometry) method was used. The response of the herbicides analyzed was linear over the concentration range of 0.02 to 2.0 microg/L. Analysis of groundwater revealed that the herbicides tebuthiuron, diuron, atrazine, simazine, and ametryn were not present in the samples. In the surface water collected in 1997, ametryn was present in two out of nine locations with concentrations ranging from 0.17 and 0.23 microg/L, which is above the allowable 0.1 microg/L according to the European safety level. The leaching potential of tebuthiuron, diuron, atrazine, simazine, 2,4-D, picloram, and hexazinone has been evaluated using CMLS-94, "Chemical Movement in Layered Soil," as simulation model. No leaching into the depth of the water table at 40 m was found.
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Abstract
The present study investigates the urinary excretion of the enantiomers of (+)- and (-)-albendazole sulfoxide (ASOX) and albendazole sulfone (ASON) in 12 patients with neurocysticercosis treated with albendazole for 8 days (7.5 mg/kg/12 h). Serial blood samples (0-12 h) and urine (three periods of 8 h) were collected after administration of the last dose of albendazole. Plasma and urine (+)-ASOX, (-)-ASOX, and ASON metabolites were determined by HPLC using a chiral phase column (Chiralpak AD) with fluorescence detection. The pharmacokinetic parameters (P < 0.05) for (+)-ASOX, (-)-ASOX, and ASON metabolites are reported as means (95% CI); amount excreted (Ae) = 3.19 (1.53-4.85) vs. 0.72 (0.41-1.04) vs. 0.08 (0.03-0.13) mg; plasma concentration-time area under the curve, AUC(0-24) = 3.56 (0.93-6.18) vs. 0.60 (0.12-1.08) vs. 0.38 (0.20-0.55) microg x h/ml, and renal clearance Cl(R) = 1.20 (0.66-1.73) vs. 2.72 (0.39-5.05) vs. 0.25 (0.13-0.37) l/h. Sulfone formation capacity, expressed as the Ae ratio ASON/ASOX + ASON, was 2.21 (1.43-2.99). These data point to enantioselectivity in the renal excretion of ASOX as a complementary mechanism to the metabolism responsible for the plasma accumulation of (+)-ASOX. The results also suggest that the metabolite ASON is partially eliminated as a reaction product of the subsequent metabolism.
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Affiliation(s)
- V L Lanchote
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, USP, Ribeirão Preto, Brazil.
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Cerdeira AL, Santos NAG, Ueta J, Shuhama IK, Pessoa MCPY, Smith S, Lanchote VL. Atrnazine in water and biodegradation in a recharge area of Guarany aquifer in Brazil. Bull Environ Contam Toxicol 2004; 73:117-124. [PMID: 15386081 DOI: 10.1007/s00128-004-0402-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Affiliation(s)
- A L Cerdeira
- Embrapa, Meio-Ambiente, Research Division of the Brazilian Ministry of Agriculture, C.P. 69, Jaguariuna, SP, 13820-000, Brazil
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Abstract
An HPLC method was developed for the determination of paroxetine in depressed geriatric patients. This method includes only one-step extraction of paroxetine from 1 ml of plasma with hexane:isoamyl alcohol (99:1, v/v). Separation was obtained using an RP select B column (250 mm x 4 mm, 5 microm) under isocratic conditions with UV detection (lambda=205 nm). The mobile phase was 0.05 mol/l sodium phosphate buffer, pH 5.0, and acetonitrile (50:50, v/v). The intra- and inter-assay accuracy and precision, determined as relative error and relative standard deviation, respectively, were less than 10%. The lower limit of quantification, with relative error and relative standard deviation of less than 10%, was 5 ng/ml. Linearity was assessed in the 5-1250 ng/ml range and recovery was 80%. Neither endogenous compounds nor other drugs were found to interfere. The assay showed high specificity, even when patients were found to be on multiple medications. In conclusion, the present method, when compared to others reported in the literature, has advantages such as simplicity, selectivity and sensitivity as a routine procedure and can be applied to the therapeutic monitoring of depressed geriatric patients.
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Affiliation(s)
- Isis A Zainaghi
- Department of Clinical, Toxicological and Food Science Analysis, Faculty of Pharmaceutical Sciences of São Paulo, Av. do Café s/n, S.P. 14040-903, Ribeirão Preto, Brazil
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Abstract
This paper reports the development of a rapid method for the enantioselective analysis of the nonsteroidal anti-inflammatory drug ibuprofen in human plasma by capillary electrophoresis employing the anionic cyclodextrin-modified electrokinetic chromatography mode. Sample cleanup was carried out by acidification with HCl followed by liquid-liquid extraction with hexane:isopropanol (99:1 v/v). The complete enantioselective analysis was performed within 10 min, using 100 mmol L(-1) phosphoric acid/triethanolamine buffer, pH 2.6, containing 2.0% w/v sulfated beta-cyclodextrin as chiral selector; fenoprofen, another nonsteroidal anti-inflammatory drug, was used as internal standard. The calibration curves were linear over the concentration range of 0.25-125.0 microg mL(-1) for each enantiomer of ibuprofen. The mean recoveries for ibuprofen enantiomers were up to 85%. The enantiomers studied could be quantified at three different concentrations (0.5, 5.0 and 50.0 microg mL(-1)) with a coefficient of variation and relative error not higher than 15%. The quantitation limit was 0.2 microg mL(-1) for (+)-(S)- and (-)-(R)-ibuprofen using 1 mL of human plasma. The plasma endogenous compounds and other drugs did not interfere with the present assay. The analysis of real plasma samples obtained from a healthy volunteer after administration of 600 mg of racemic ibuprofen showed a maximum plasma level of 29.6 and 39.9 microg mL(-1) of (-)-(R)- and (+)-(S)-ibuprofen, respectively, and the area under plasma concentration-time curve AUC(0-infinity) (+)-(S)/AUC(0-infinity) (-)-(R) ratio was 1.87.
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Affiliation(s)
- Valquíria A P Jabor
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, SP, Brazil
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Takayanagui OM, Bonato PS, Dreossi SAC, Lanchote VL. Enantioselective distribution of albendazole metabolites in cerebrospinal fluid of patients with neurocysticercosis. Br J Clin Pharmacol 2002; 54:125-30. [PMID: 12207631 PMCID: PMC1874411 DOI: 10.1046/j.1365-2125.2002.01634.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AIMS Albendazole (ABZ) is effective in the treatment of neurocysticercosis. ABZ undergoes extensive metabolism to (+) and (-)-albendazole sulphoxide (ASOX), which are further metabolized to albendazole sulphone (ASON). We have investigated the distribution of (+)-ASOX (-)-ASOX, and ASON in cerebrospinal fluid (CSF) of patients with neurocysticercosis. METHODS Twelve patients with a diagnosis of active brain parenchymal neurocysticercosis treated with albendazole for 8 days (15 mg kg(-1) day(-1)) were investigated. On day 8, serial blood samples were collected during the dose interval (0-12 h) and one CSF sample was taken from each patient by lumbar puncture at different time points up to 12 h after the last albendazole dose. Albendazole metabolites were determined in CSF and plasma samples by h.p.l.c. using a Chiralpak AD column and fluorescence detection. Population curves for CSF albendazole metabolite concentration vs time were constructed. RESULTS The mean plasma/CSF ratios were 2.6 (95% CI: 1.9, 3.3) for (+)-ASOX and 2.7 (95% CI: 1.8, 3.7) for (-)-ASOX, with the two-tailed P value of 0.9873 being non-significant. These data indicate that the transport of ASOX through the blood-brain barrier is not enantioselective, but rather depends on passive diffusion. The present results suggest the accumulation of the (+)-ASOX metabolite in the CSF of patients with neurocysticercosis. The CSF AUC(+)/AUC(-) ratio was 3.4 for patients receiving albendazole every 12 h. The elimination half-life of both ASOX enantiomers in CSF was 2.5 h. ASOX was the predominant metabolite in the CSF compared with ASON; the CSF AUC(ASOX)/AUC(ASON) ratio was approximately 20 and the elimination half-life of ASON in CSF was 2.6 h. CONCLUSIONS We have demonstrated accumulation of the (+)-ASOX metabolite in CSF, which was about three times greater than the (-) antipode. ASOX concentrations were approximately 20 times higher than those observed for the ASON metabolite.
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Affiliation(s)
- O M Takayanagui
- Faculdade de Medicina de Ribeirão Preto, USP, Ribeirão Preto, Brazil
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Lanchote VL, Garcia FS, Dreossi SAC, Takayanagui OM. Pharmacokinetic interaction between albendazole sulfoxide enantiomers and antiepileptic drugs in patients with neurocysticercosis. Ther Drug Monit 2002; 24:338-45. [PMID: 12021623 DOI: 10.1097/00007691-200206000-00003] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The aim of the present investigation was to determine the interaction between the antiepileptic drugs (AEDs) phenytoin, carbamazepine, and phenobarbital and the enantioselective metabolism of albendazole. Thirty-two adults with a diagnosis of the active form of intraparenchymatous neurocysticercosis and treated with albendazole at the dose of 7.5 mg/kg every 12 hours for 8 days were studied. The patients were divided into four groups based on the combined use of AEDs or not: control group (n = 9), phenytoin group (n = 9 patients treated with 3-4 mg/kg/d sodium phenytoin), carbamazepine group (n = 9 patients treated with 10-20 mg/kg/d carbamazepine), and phenobarbital group (n = 5 patients treated with 1.5-4.5 mg/kg/d phenobarbital). Serial blood collections were carried out on day 8 of albendazole treatment during the last 12-hour dose interval. Plasma concentrations of the (+)- and (-)-albendazole sulfoxide (ASOX) and albendazole sulfone (ASON) metabolites were determined by high-performance liquid chromatography using a chiral phase column and fluorescence detection. The pharmacokinetic parameters were analyzed by analysis of variance followed by the Tukey-Kramer test. The results are reported as means. The following differences (P < 0.05) were observed between the control and the phenytoin, carbamazepine, and phenobarbital groups, respectively: (+)-ASOX area under the concentration-time curve for 0 to 12 hours after treatment (AUC(0-12)) 6.1, 2.1, 3.1, 2.4 microg/h/mL; (+)-ASOX maximum plasma concentration (C(max)) 0.8, 0.3, 0.4, 0.3 microg/mL; (+)-ASOX half-life (t1/2) 8.0, 3.8, 4.1, 4.9 h; (-)-ASOX AUC(0-12) 1.8, 0.4, 0.6, 0.5 microg/h/mL; (-)-ASOX C(max) 0.2, 0.06, 0.1, 0.1 microg/mL; (-)-ASOX (t(1/2)) 4.3, 1.9, 2.2, 2.1 h; ASON AUC(0-12) 0.5, 0.2 microg/h/mL; ASON C(max) 0.8, 0.3, 0.4, 0.3 microg/mL; ASON (t(1/2)) 8.0, 3.8, 4.1 h. The results show that phenytoin, carbamazepine, and phenobarbital induce to approximately the same extent the oxidative metabolism of albendazole in a nonenantioselective manner. Notably, a significant reduction in the plasma concentration of the active ASOX metabolite was observed in patients with neurocysticercosis treated with these AEDs.
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Affiliation(s)
- Vera L Lanchote
- Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Avenida Bandeirantes 3900, 14049-900 Ribeirão Preto, SP, Brazil
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37
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Marques MP, Takayanagui OM, Lanchote VL. Albendazole metabolism in patients with neurocysticercosis: antipyrine as a multifunctional marker drug of cytochrome P450. Braz J Med Biol Res 2002; 35:261-9. [PMID: 11847531 DOI: 10.1590/s0100-879x2002000200016] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The present study investigates the isoform(s) of cytochrome P450 (CYP) involved in the metabolism of albendazole sulfoxide (ASOX) to albendazole sulfone (ASON) in patients with neurocysticercosis using antipyrine as a multifunctional marker drug. The study was conducted on 11 patients with neurocysticercosis treated with a multiple dose regimen of albendazole for 8 days (5 mg/kg every 8 h). On the 5th day of albendazole treatment, 500 mg antipyrine was administered po. Blood and urine samples were collected up to 72 h after antipyrine administration. Plasma concentrations of (+)-ASOX, (-)-ASOX and ASON were determined by HPLC using a chiral phase column and detection by fluorescence. The apparent clearance (CL/f) of ASON and of the (+) and (-)-ASOX enantiomers were calculated and compared to total antipyrine clearance (CL(T)) and the clearance for the production of the three major antipyrine metabolites (CLm). A correlation (P<or=0.05) was obtained only between the CL(T) of antipyrine and the CL/f of ASON (r = 0.67). The existence of a correlation suggests the involvement of CYP isoforms common to the metabolism of antipyrine and of ASOX to ASON. Since the CL(T) of antipyrine is a general measure of CYP enzymes but with a slight to moderate weight toward CYP1A2, we suggest the involvement of this enzyme in ASOX to ASON metabolism in man. The study supports the establishment of a specific marker drug of CYP1A2 in the study of the in vivo metabolism of ASOX to ASON.
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Affiliation(s)
- M P Marques
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
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38
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Lanchote VL, Rocha A, de Albuquerque FU, Coelho EB, Bonato PS. Stereoselective analysis of fluvastatin in human plasma for pharmacokinetic studies. J Chromatogr B Biomed Sci Appl 2001; 765:81-8. [PMID: 11817313 DOI: 10.1016/s0378-4347(01)00407-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Fluvastatin, an inhibitor of cholesterol biosynthesis, is commercialized as a racemic mixture of the (+)-3R,5S and (-)-3S,5R stereoisomers, although inhibition of HMG-CoA reductase mainly resides in the (+)-(3R,5S)-fluvastatin isomer. The aim of the present study was to analyze fluvastatin isomers in human plasma with application to studies on kinetic disposition. Plasma samples of 1 ml were eluted into 3 ml LC-18 Supelclean (Supelco) columns equilibrated with methanol and water. The columns were washed with water and acetonitrile and then eluted with methanol containing 0.2% diethylamine. The (+)-3R,5S and (-)-3S,5R isomers were separated by HPLC on a Chiralcel OD-H chiral phase column and detected by fluorescence (lambda(ex) 305 nm; lambda(em) 390 nm). The quantification limit was 0.75 ng for each isomer/ml plasma and linearity was observed up to 625 ng/ml. The relative standard deviations obtained for intra- and inter-assay precision were lower than 10% and the recovery was higher than 80% for both enantiomers. Application of the method to a stereoselective study on the pharmacokinetics of fluvastatin administered as a single oral dose (Lescol, 20 mg) to a healthy volunteer revealed stereoselectivity, with the highest plasma concentrations being observed for the (-)-3S,5R isomer (Cmax 92.4 vs. 60.3 ng/ml, AUC(0-infinity) 133.3 vs. 97.4 ng h/ml, Cl/f 150.2 vs. 205.2 l h(-1) and Vd/f 4.4 vs. 6.0 l/kg).
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Affiliation(s)
- V L Lanchote
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, SP, Brazil.
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39
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Marques MP, Santos NA, Coelho EB, Bonato PS, Lanchote VL. Enantioselective assay of nisoldipine in human plasma by chiral high-performance liquid chromatography combined with gas chromatographic-mass spectrometry: applications to pharmacokinetics. J Chromatogr B Biomed Sci Appl 2001; 762:87-95. [PMID: 11589462 DOI: 10.1016/s0378-4347(01)00352-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Nisoldipine, a second-generation dihydropyridine calcium antagonist, is a racemate compound used in the treatment of hypertension and coronary heart disease. This study presents an enantioselective HPLC-GC-MS method for the analysis of nisoldipine in human plasma and establishes confidence limits for its application to pharmacokinetic studies. Plasma samples were basified and extracted with toluene. The enantiomers were resolved on a Chiralcel OD-H column using hexane-ethanol (97.5:2.5, v/v) and the (+)- and (-)-fractions were collected separately with the diode array detector switched off. For the quantification of the nisoldipine enantiomers a GC-MS with an Ultra 1 Hewlett-Packard column was used with the detector operated in the single-ion monitoring mode with electron-impact ionization (m/z 371.35 and 270.20 for nisoldipine and m/z 360.00 for the internal standard, nitrendipine). The method proved to be suitable for pharmacokinetic studies based on the low quantification limit (0.05 ng/ml for each enantiomer) and the broad linear range (0.05-50.0 ng/ml for each enantiomer). Low coefficients of variation (<15%) were demonstrated for both within-day and between-day assays. No interference from drugs associated with nisoldipine treatment was observed. The enantioselective pilot study on the kinetic disposition of nisoldipine administered in the racemic form to a hypertensive patient using a multiple dose regimen revealed the accumulation of the (+)-enantiomer with an AUC(0-24) (+)/(-) ratio of approximately 8. Both enantiomers were quantified in plasma at a time interval of 24 h. This HPLC-GC-MS method is reliable, selective and sensitive enough to be used in clinical pharmacokinetic studies on the enantioselective disposition of nisoldipine in humans.
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Affiliation(s)
- M P Marques
- Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Brazil
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40
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Abstract
Albendazole (ABZ) is a benzimidazole anthelmintic drug used in the treatment of neurocysticercosis. After oral administration, ABZ is rapidly oxidized to albendazole sulfoxide (ABZSO), which has an asymmetric sulfur center, and later to albendazole sulfone (ABZSO2). ABZSO is the active metabolite responsible for the therapeutic effect of the drug. Previous studies have demonstrated pharmacokinetic differences between the two enantiomers, with the predominance of (+)-ABZSO in human biological fluids. This article describes for the first time the enantioselective analysis of ABZSO in cerebrospinal fluid (CSF) using capillary electrophoresis. The samples were prepared by liquid-liquid extraction using chloroform:isopropanol (8:2 v/v). The resolution of ABZSO enantiomers was obtained with a fused-silica capillary (60 cm x 75 microm ID) using 20 mmol/L Tris, pH 7.0, with 3.0% w/w sulfated beta-cyclodextrin as running buffer. The coefficient of variations and % relative error obtained for both within-day and between-days assays were lower than 15%. The method was linear over the concentration range of 100 to 2,500 ng/mL for each enantiomer, indicating that it is suitable for the analysis of ABZSO enantiomers in CSF from patients medicated with ABZ.
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Affiliation(s)
- F O Paias
- Departamento de Química, Facultade de Filosofia, Ciências e Letras de Ribeirão Preto, Brazil
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41
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Abstract
In this paper, a rapid method for the enantioselective analysis of the antiarrhythmic drug disopyramide and its main metabolite mono-N-dealkyldisopyramide in human plasma by capillary electrophoresis employing the cyclodextrin-modified electrokinetic chromatography mode is described. Sample clean-up was carried out by alkalinization with sodium hydroxide followed by liquid-liquid extraction with toluene. The complete enantioselective analysis was performed within less than 5 min using 20 mmol/L sodium acetate buffer, pH 5.0, containing 0.2% w/v sulfated beta-cyclodextrin as chiral selector. A 40 cm uncoated fused-silica capillary was used for the analysis, performed at a voltage of 15 kV and at 20 degrees C. The calibration curves were linear over the concentration range of 62.5-1850 ng/mL and 125-1850 ng/mL for each enantiomer of disopyramide and mono-N-dealkyldisopyramide. The mean recoveries for disopyramide and mono-N-dealkyldisopyramide enantiomers were up to 87 and 69%, respectively. All four enantiomers studied could be quantified at three different concentrations (200, 400 and 600 ng/mL) with coefficient of variation and % relative error not higher than 15%. The quantitation limit was 62.5 ng/mL for (+)-(S)-and (-)-(R)-disopyramide and (-)-(R)-mono-N-dealkyldisopyramide and 125 ng/mL for (+)-(S)-mono-N-dealkyldisopyramide, using 1 mL of human plasma.
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Affiliation(s)
- V A Jabor
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, SP, Brazil
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42
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Abstract
In the present study we investigated the enantioselectivity in the pharmacokinetics of metoprolol administered in a multiple-dose regimen as the racemate. The study was conducted on 10 patients of both sexes with mild to severe essential hypertension, aged 28 to 76 years, with normal hepatic and renal function and phenotyped as extensive metabolizers of debrisoquine (urine debrisoquine to 4-hydroxydebrisoquine ratios of 0.28 to 6.56). The patients were treated with racemic metoprolol (two 100 mg tablets every 24 h) for 7 days. Serial blood samples were collected at times zero, 0.5, 1, 1.5, 2, 3, 4, 6, 8, 10, 12, 16, 20, 22, and 24 h and urine at each 6 h period until 24 h after metoprolol administration. The plasma concentrations of the (-)-(S)- and (+)-(R)-metoprolol enantiomers were determined by HPLC using a chiral stationary phase (Chiralpak AD, 4.6 x 250 mm) and fluorescence detection. The enantiomeric ratios differing from one were evaluated by the paired t test and the results are reported as means (95% CI). No differences were observed between metoprolol enantiomers in half-lives and absorption, distribution and elimination rate constants. However, the following differences (p < 0.05) were observed between the (-)-(S) and (+)-(R) enantiomers: maximum plasma concentration, C(max), 179.99 (123. 33-236.64) versus 151.30 (95.04-207.57) ng/mL; area under the plasma concentration versus time curve, AUC(0-24)(SS), 929.85 (458.02-1401. 70) versus 782.11 (329.80-1234.40) ng h/mL; apparent total clearance, Cl(T)/f, 1.70 (0.79-2.61) versus 2.21 (1.06-3.36) L/h/kg, apparent distribution volume, Vd/f, 10.51 (6.35-14.68) versus 13.80 (6.93-20. 68) L/kg, and renal clearance, Cl(R), 0.06 (0.05-0.08) versus 0.07 (0.05-0.09) L/kg. The enantiomeric ratios AUC((-)-(S))/AUC((+)-(R)) ranged from 1.14 to 1.44, with a mean of 1.29. The data obtained demonstrate enantioselectivity in the kinetic disposition of metoprolol, with plasma accumulation of the pharmacologically more active (-)-(S)-metoprolol enantiomer in hypertensive patients phenotyped as extensive metabolizers of debrisoquine.
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Affiliation(s)
- P M Cerqueira
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
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Cerqueira PM, Mateus FH, Cesarino EJ, Bonato PS, Lanchote VL. Enantioselectivity of debrisoquine 4-hydroxylation in Brazilian Caucasian hypertensive patients phenotyped as extensive metabolizers. J Chromatogr B Biomed Sci Appl 2000; 749:153-61. [PMID: 11145052 DOI: 10.1016/s0378-4347(00)00402-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Debrisoquine (D), an antihypertensive drug metabolized to 4-hydroxydebrisoquine (4-OHD) by CYP2D6, is commonly used as an in vivo probe of CYP2D6 activity and can be used to phenotype individuals as either extensive (EMs) or poor metabolizers (PMs) of such drugs as beta-adrenergic blockers, tricyclic antidepressants, and class 1C antiarrhythmics. This report describes reversed-phase HPLC systems by which D and 4-OHD or S-(+) and R-(-)-4-OHD in urine are more selectively quantified without the need for derivatization techniques. We also studied the urinary excretion of R-(-)- and S-(+)-4-hydroxydebrisoquine in EM hypertensive patients in order to determine weather 4-OHD formation exhibits enantioselectivity. Twelve patients with mild to severe essential hypertension were admitted to the study. They received a single tablet of Declinax containing 10 mg debrisoquine sulfate. All the urine excreted during the following 8 h was collected. The debrisoquine metabolic ratio (DMR) was calculated as % of dose excreted as D/% of dose excreted as 4-OHD and the debrisoquine recovery ratio (DRR) was calculated as % of dose excreted as 4-OHD/% of dose excreted as D+4-OHD. Debrisoquine and its metabolite were determined in urine by HPLC using a reversed-phase Select B LiChrospher column, a mobile phase of 0.25 N acetate buffer, pH 5-acetonitrile (9:1, v/v) and a fluorescence detector. The limit of quantitation was determined to be 25.0 ng/ml for D and 18.75 ng/ml for 4-OHD. Intra- and inter-day relative standard deviations (RSDs) were less than 10%. All hypertensive patients studied showed a DMR of less than 12.6 or a DRR higher than 0.12 and were classified as EMs. Direct enantioselective separation on chiral stationary phase involved resolution of S-(+)-4-OHD and R-(-)-4-OHD on a Chiralcel OD-R column with a mobile phase of 0.125 N sodium perchlorate, pH 5-acetonitrile-methanol (85:12:3, v/v/v). The quantitation limit of each enantiomer was 3.75 ng/ml of urine. Intra- and inter-day RSDs were less than 10% for each enantiomer. A high degree of enantioselectivity in the 4-hydroxylation of D favouring the S-(+) enantiomer was observed, resulting in R-(-)-4-OHD not detected in the urine of the EM hypertensive patients studied.
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Affiliation(s)
- P M Cerqueira
- Universidade de São Paulo, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Brazil
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44
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Bortocan R, Lanchote VL, Cesarino EJ, Bonato PS. Enantioselective analysis of disopyramide and mono-N-dealkyldisopyramide in plasma and urine by high-performance liquid chromatography on an amylose-derived chiral stationary phase. J Chromatogr B Biomed Sci Appl 2000; 744:299-306. [PMID: 10993518 DOI: 10.1016/s0378-4347(00)00255-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
An enantioselective high-performance liquid chromatography method was developed for the simultaneous determination of disopyramide (DP) and mono-N-dealkyldisopyramide (MND) enantiomers in plasma and urine. The drugs were extracted from plasma samples by liquid-liquid extraction with dichloromethane after protein precipitation with trichloroacetic acid; the urine samples were processed by liquid-liquid extraction with dichloromethane. The enantiomers were resolved on a Chiralpak AD column using hexane-ethanol (91:9, v/v) plus 0.1% diethylamine as the mobile phase and monitored at 270 nm. Under these conditions the enantiomeric fractions of the drug and of its metabolite were analyzed within 20 min. The extraction procedure was efficient in removing endogenous interferents and low values for the relative standard deviations were demonstrated for both within-day and between-day assays. The method described in this paper allows the determination of DP and MND enantiomers at plasma levels as low as 12.5 ng/ml and can be used in clinical pharmacokinetic studies.
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Affiliation(s)
- R Bortocan
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto-USP, Brazil
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Bonato PS, de Abreu LR, de Gaitani CM, Lanchote VL, Bertucci C. Enantioselective HPLC analysis of propafenone and of its main metabolites using polysaccharide and protein-based chiral stationary phases. Biomed Chromatogr 2000. [PMID: 10861733 DOI: 10.1002/1099-0801(200006)14:4<227::aid-bmc971>3.0.co;2-q] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
HPLC on chiral stationary phases has been used for the enantioselective assay of propafenone (PPF), 5-hydroxypropafenone (PPF-50H) and N-despropylpropafenone (PPF-NOR) enantiomers. The results obtained on Chiralpak AD column showed that it is useful for the resolution of PPF and of its main metabolites, although the peaks obtained for PPF-NOR were not symmetrical under the conditions investigated. This column and circular dichroism-based detection system were used to determine the absolute configuration of the eluates. Furthermore, the influence of the mobile phase composition on the resolution of PPF and of its main metabolites was investigated on cellulose derivatives (Chiralcel OD-H and Chiralcel OD-R) and protein (Chiral AGP and Ultron ES-OVM)-based chiral stationary phases. The enantiomers of PPF were resolved on all the columns, except for the Ultron ES-OVM. This column, the Chiralpak AD and the Chiralcel OD-H columns were suitable for the resolution of the PPF-50H enantiomers. The PPF-NOR enantiomers were resolved on the Chiralpak AD, Chiral AGP and Chiralcel OD-R columns.
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Affiliation(s)
- P S Bonato
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto-USP, Ribeirão Preto, Brazil
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Abstract
The enantioselectivity of the kinetic disposition of albendazole sulfoxide (ASOX) was investigated in 18 patients with neurocysticercosis treated with a multiple dose regimen of albendazole for 8 days (5 mg/kg every 8 h). Serial blood samples were collected on the eighth day of treatment during the last dose interval, with prorogation up to 12 h. Albendazole sulfone (ASON) and enantiomers of ASOX were analyzed in plasma samples by HPLC using a Chiralpak AD column and detection by fluorescence. The pharmacokinetic parameters showing statistically significant differences between the (+) ASOX and (-) ASOX enantiomers are presented as respective means (95% CI) as follows: maximum plasma concentration, Cmax = 301.6 (179.7-423.5) vs 54.9 (21.9-87.9) ng.ml-1; elimination half-life, t1/2 = 5.2 (4.1-6.3) vs 3.3 (2.8-3.8) h, area under the plasma concentration-time curve, AUCss0-8 = 1719.2 (978.6-2459.8) vs 261.4 (102.9-419.8) ng.h.ml-1 and apparent clearance, Cl/fm = 5.8 (3.8-7.8) vs 54.0 (35.2-72.7) l.h-1.kg-1. The mean value of 9.2 (7.6-10.9) for the AUC0-8(+)-ASOX/AUC0-8(-)-ASOX ratio demonstrated plasma accumulation of the (+) enantiomer. Sulfone formation capacity, expressed by the AUCss0-8 ratio ASON/ASOX + ASON, was 8.0 (7.0-8.9). The present data indicate enantioselectivity in the kinetic disposition of ASOX in patients with neurocysticercosis.
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Affiliation(s)
- M P Marques
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Brazil
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Abstract
We present a method for the enantioselective analysis of albendazole sulfoxide (ABZSO) in plasma for application in clinical pharmacokinetic studies. ABZSO enantiomers were separated on a 5-micron Chiralcel OB-H column (4.6 x 150 mm) using hexane:ethanol (93:7, v/v) as the mobile phase and fluorescence detection. ABZSO was extracted with chloroform:isopropanol (8:2, v/v) from 500-microliter aliquots of acidified plasma, with full drug recovery. The proposed method presented quantitation limits of 20 ng/ml for (-)ABZSO and 50 ng/ml for (+)ABZSO and was linear up to a concentration of 5,000 ng/ml of each enantiomer.
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Affiliation(s)
- F O Paias
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto-USP, Brazil
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Lanchote VL, Cesarino EJ, Santos VJ, Mere Júnior Y, Santos SR. Enantioselectivity in the metabolism of mexiletine by conjugation in female patients with the arrhythmic form of chronic Chagas' heart disease. Chirality 2000; 11:29-32. [PMID: 9914650 DOI: 10.1002/(sici)1520-636x(1999)11:1<29::aid-chir5>3.0.co;2-u] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The phenomenon of enantioselectivity in the metabolism of mexiletine (MEX) conjugation was investigated in eight female patients with the arrhythmic form of chronic Chagas' heart disease treated with racemic mexiletine hydrochloride (two 100 mg capsules every 8 hr). Blood samples were collected up to 24 hr after the administration of the morning dose, with discontinuation of the subsequent doses during the study period. Plasma concentrations of N-hydroxymexiletine glucuronide were calculated as the difference between the concentrations of unchanged and total (unchanged + conjugated) MEX enantiomers. Total plasma MEX concentrations were analyzed by HPLC after enzymatic hydrolysis with beta-glucuronidase, the formation of diastereomeric derivatives with the chiral reagent N-acetyl-L-cysteine/o-phthalaldehyde, and fluorescence detection. The differences in the pharmacokinetic parameters of the enantiomers were evaluated by the paired t-test. The plasma concentrations of the (+)-(S)-MEX did not differ before and after enzymatic hydrolysis. The pharmacokinetic parameters calculated for (-)-(R)-N-hydroxymexiletine glucuronide are presented as means (95% confidence interval): maximum plasma concentration Cmax = 194.0 ng.ml-1 (154.3-233.7), time to maximum plasma concentration tmax = 1.4 hr (0.3-2.5), area under the plasma concentration versus time curve AUC0-24 = 2099.2 ng.h.ml-1 (1585.6-2612.6), elimination half-life t1/2 beta = 12.8 hr (9.9-15.6) and extent of conjugation of 31.6% (24.3-38.9%). The present data indicate stereospecific conjugation of (-)-(R)-N-hydroxymexiletine in the female patients with the arrhythmic form of Chagas' heart disease.
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Affiliation(s)
- V L Lanchote
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
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49
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Abstract
Pre-column derivatization with o-phthaldialdehyde and N-acetyl-l-cysteine was used for liquid-chromatographic diastereomeric resolution of p-hydroxymexiletine (PHM) and hydroxymethylmexiletine (HMM), metabolites of mexiletine formed by aromatic and aliphatic hydroxylation, respectively. The resulting diastereomeric derivatives were resolved on a C18 column and monitored by fluorescence detection. The diastereomeric elution order for both metabolites was determined on the basis of the circular dichroism spectra of each eluted fraction. Plasma samples (500 microliters) showed recoveries greater than 75% for both the metabolites. Calibration curves in plasma samples were linear over the concentration ranges 10-500 and 20-1,000 ng/ml for each enantiomer of PHM and HMM, respectively. The limits of quantitation were found to be 10.0 and 5.0 ng/ml for both enantiomers of PHM and HMM. The within-day and between-day coefficients of variation were less than 10%. The assay was shown to be suitable for a pharmacokinetic study performed in a patient with ventricular arrhythmias following the short-term oral treatment of 200 mg t.i.d. of racemic mexiletine hydrochloride.
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Affiliation(s)
- V L Lanchote
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Brazil
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Bonato PS, de Abreu LR, de Gaitani CM, Lanchote VL, Bertucci C. Enantioselective HPLC analysis of propafenone and of its main metabolites using polysaccharide and protein-based chiral stationary phases. Biomed Chromatogr 2000; 14:227-33. [PMID: 10861733 DOI: 10.1002/1099-0801(200006)14:4<227::aid-bmc971>3.0.co;2-q] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
HPLC on chiral stationary phases has been used for the enantioselective assay of propafenone (PPF), 5-hydroxypropafenone (PPF-50H) and N-despropylpropafenone (PPF-NOR) enantiomers. The results obtained on Chiralpak AD column showed that it is useful for the resolution of PPF and of its main metabolites, although the peaks obtained for PPF-NOR were not symmetrical under the conditions investigated. This column and circular dichroism-based detection system were used to determine the absolute configuration of the eluates. Furthermore, the influence of the mobile phase composition on the resolution of PPF and of its main metabolites was investigated on cellulose derivatives (Chiralcel OD-H and Chiralcel OD-R) and protein (Chiral AGP and Ultron ES-OVM)-based chiral stationary phases. The enantiomers of PPF were resolved on all the columns, except for the Ultron ES-OVM. This column, the Chiralpak AD and the Chiralcel OD-H columns were suitable for the resolution of the PPF-50H enantiomers. The PPF-NOR enantiomers were resolved on the Chiralpak AD, Chiral AGP and Chiralcel OD-R columns.
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Affiliation(s)
- P S Bonato
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto-USP, Ribeirão Preto, Brazil
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