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Vanbrabant TJF, Dijkmans AC, den Hartigh J, Touw DJ, Arend SM. Rifampin levels in daily practice: the accuracy of a single measurement. Neth J Med 2018; 76:235-242. [PMID: 30019679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
BACKGROUND Measurement of rifampin levels is not part of routine practice. However, low levels are associated with failure of tuberculosis treatment. The clinical relevance of serum levels in daily practice is unclear. The objective was to evaluate rifampin serum concentrations and factors associated with insufficient concentrations. METHODS Patients with at least one rifampin concentration drawn 3 hours after intake (C3) between 2005 and 2014 were included. Data on demographic and clinical characteristics were collected, including side effects and dose adjustments. Two different criteria were used to define adequate concentrations (criterion 1: C3 a nd C 6 ≥ 3 mg/l; criterion 2: C3 or C6 ≥ 5 mg/l). RESULTS Of 63 patients, 66% and 76% had a sufficient level according to criterion 1 or 2, respectively. C3 exceeded C6 in most patients, while a late maximum was significantly associated with diabetes mellitus (p = 0.003). A dose adjustment was made in 19% of cases, more frequently in patients with insufficient levels (p = 0.02) or with ≥ 2 side effects (p = 0.03). CONCLUSION Rifampin levels varied but were mostly adequate and a single measurement at 3 hours after intake provided the required information in most cases, indicating that full AUC0-24 measurements could be limited to specific situations.
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Affiliation(s)
- T J F Vanbrabant
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, the Netherlands
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Bertina RM, van der Meer FJM, den Hartigh J, van den Besselaar AMHP. Different Sensitivities of Various Thromboplastins to Two Blood Collection Systems for Monitoring Oral Anticoagulant Therapy. Thromb Haemost 2017. [DOI: 10.1055/s-0037-1614649] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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de Wit D, Schneider TC, Moes DJAR, Roozen CFM, den Hartigh J, Gelderblom H, Guchelaar HJ, van der Hoeven JJ, Links TP, Kapiteijn E, van Erp NP. Everolimus pharmacokinetics and its exposure-toxicity relationship in patients with thyroid cancer. Cancer Chemother Pharmacol 2016; 78:63-71. [PMID: 27169792 PMCID: PMC4921118 DOI: 10.1007/s00280-016-3050-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 04/27/2016] [Indexed: 12/16/2022]
Abstract
Background Everolimus is a mTOR inhibitor used for the treatment of different solid malignancies. Many patients treated with the registered fixed 10 mg dose once daily are in need of dose interruptions, reductions or treatment discontinuation due to severe adverse events. This study determined the correlation between systemic everolimus exposure and toxicity. Additionally, the effect of different covariates on everolimus pharmacokinetics (PK) was explored. Methods Forty-two patients with advanced thyroid carcinoma were treated with 10 mg everolimus once daily. Serial pharmacokinetic sampling was performed on days 1 and 15. Subsequently, a population PK model was developed using NONMEM to estimate individual PK values used for analysis of an exposure–toxicity relationship. Furthermore, this model was used to investigate the influence of patient characteristics and genetic polymorphisms in genes coding for enzymes relevant in everolimus PK. Results Patients who required a dose reduction (n = 18) due to toxicity at any time during treatment had significant higher everolimus exposures [mean AUC0–24 (SD) 600 (274) vs. 395 (129) µg h/L, P = 0.008] than patients without a dose reduction (n = 22). A significant association between everolimus exposure and stomatitis was found in the four-level ordered logistic regression analysis (P = 0.047). The presence of at least one TTT haplotype in the ABCB1 gene was associated with a 21 % decrease in everolimus exposure. Conclusion The current study showed that dose reductions and everolimus-induced stomatitis were strongly associated with systemic everolimus drug exposure in patients with cancer. Our findings confirm observations from another study in patients with cancer and show us that everolimus is a good candidate for individualized dosing in patients with cancer. ClinicalTrial.gov number NCT01118065. Electronic supplementary material The online version of this article (doi:10.1007/s00280-016-3050-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- D de Wit
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, Leiden, The Netherlands
| | - T C Schneider
- Department of Medical Oncology, Leiden University Medical Center, Leiden, The Netherlands
| | - D J A R Moes
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, Leiden, The Netherlands
| | - C F M Roozen
- Department of Medical Oncology, Leiden University Medical Center, Leiden, The Netherlands
| | - J den Hartigh
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, Leiden, The Netherlands
| | - H Gelderblom
- Department of Medical Oncology, Leiden University Medical Center, Leiden, The Netherlands
| | - H J Guchelaar
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, Leiden, The Netherlands
| | - J J van der Hoeven
- Department of Medical Oncology, Leiden University Medical Center, Leiden, The Netherlands
| | - T P Links
- Department of Endocrinology, University Medical Center Groningen, Groningen, The Netherlands
| | - E Kapiteijn
- Department of Medical Oncology, Leiden University Medical Center, Leiden, The Netherlands
| | - N P van Erp
- Department of Clinical Pharmacy, Radboud University Medical Center, Postbus 9101, 6500 HB, Nijmegen, The Netherlands.
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Moes DJAR, Swen JJ, van der Bent SAS, van der Straaten T, Inderson A, Olofsen E, Verspaget HW, Guchelaar HJ, den Hartigh J, van Hoek B. Response: Limited sampling strategies for once daily tacrolimus exposure monitoring. Eur J Clin Pharmacol 2016; 72:775-6. [PMID: 26931555 DOI: 10.1007/s00228-016-2036-y] [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: 02/24/2016] [Accepted: 02/25/2016] [Indexed: 12/01/2022]
Affiliation(s)
- D J A R Moes
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, Leiden, The Netherlands.
| | - J J Swen
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, Leiden, The Netherlands
| | - S A S van der Bent
- Department of Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, The Netherlands
| | - T van der Straaten
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, Leiden, The Netherlands
| | - A Inderson
- Department of Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, The Netherlands
| | - E Olofsen
- Department of Anesthesiology, Leiden University Medical Center, Leiden, The Netherlands
| | - H W Verspaget
- Department of Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, The Netherlands
| | - H J Guchelaar
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, Leiden, The Netherlands
| | - J den Hartigh
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, Leiden, The Netherlands
| | - B van Hoek
- Department of Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, The Netherlands
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van Rongen A, Kervezee L, Brill MJE, van Meir H, den Hartigh J, Guchelaar HJ, Meijer JH, Burggraaf J, van Oosterhout F. Population Pharmacokinetic Model Characterizing 24-Hour Variation in the Pharmacokinetics of Oral and Intravenous Midazolam in Healthy Volunteers. CPT Pharmacometrics Syst Pharmacol 2015; 4:454-64. [PMID: 26380154 PMCID: PMC4562161 DOI: 10.1002/psp4.12007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 06/11/2015] [Indexed: 12/19/2022] Open
Abstract
Daily rhythms in physiology may affect the pharmacokinetics of a drug. The aim of this study was to evaluate 24-hour variation in the pharmacokinetics of the CYP3A substrate midazolam. Oral (2 mg) and intravenous (1 mg) midazolam was administered at six timepoints throughout the 24-hour period in 12 healthy volunteers. Oral bioavailability (population mean value [RSE%] of 0.28 (7.1%)) showed 24-hour variation that was best parameterized as a cosine function with an amplitude of 0.04 (17.3%) and a peak at 12:14 in the afternoon. The absorption rate constant was 1.41 (4.7%) times increased after drug administration at 14:00. Clearance (0.38 L/min (4.8%)) showed a minor 24-hour variation with an amplitude of 0.03 (14.8%) L/min and a peak at 18:50. Simulations show that dosing time minimally affects the concentration time profiles after intravenous administration, while concentrations are higher during the day compared to the night after oral dosing, reflecting considerable variation in intestinal processes.
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Affiliation(s)
- A van Rongen
- Department of Clinical Pharmacy, St. Antonius HospitalNieuwegein, The Netherlands
- Division of Pharmacology, Leiden Academic Centre for Drug Research, Leiden UniversityLeiden, The Netherlands
| | - L Kervezee
- Division of Pharmacology, Leiden Academic Centre for Drug Research, Leiden UniversityLeiden, The Netherlands
- Department of Molecular Cell Biology, Leiden University Medical CenterLeiden, The Netherlands
- Centre for Human Drug ResearchLeiden, The Netherlands
| | - MJE Brill
- Department of Clinical Pharmacy, St. Antonius HospitalNieuwegein, The Netherlands
- Division of Pharmacology, Leiden Academic Centre for Drug Research, Leiden UniversityLeiden, The Netherlands
| | - H van Meir
- Centre for Human Drug ResearchLeiden, The Netherlands
| | - J den Hartigh
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical CenterLeiden, The Netherlands
| | - H-J Guchelaar
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical CenterLeiden, The Netherlands
| | - JH Meijer
- Department of Molecular Cell Biology, Leiden University Medical CenterLeiden, The Netherlands
| | - J Burggraaf
- Division of Pharmacology, Leiden Academic Centre for Drug Research, Leiden UniversityLeiden, The Netherlands
- Centre for Human Drug ResearchLeiden, The Netherlands
| | - F van Oosterhout
- Department of Molecular Cell Biology, Leiden University Medical CenterLeiden, The Netherlands
- Centre for Human Drug ResearchLeiden, The Netherlands
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Kerkhofs TMA, Derijks LJJ, Ettaieb MHT, Eekhoff EMW, Neef C, Gelderblom H, den Hartigh J, Guchelaar HJ, Haak HR. Short-term variation in plasma mitotane levels confirms the importance of trough level monitoring. Eur J Endocrinol 2014; 171:677-83. [PMID: 25201518 DOI: 10.1530/eje-14-0388] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Mitotane is the drug of choice in patients with adrenocortical carcinoma. The anti-neoplastic effect is correlated with mitotane plasma levels, which render it crucial to reach and maintain the concentration above 14 mg/l. However, mitotane pharmacokinetics is poorly understood. The aim of this study was to investigate the variation in plasma mitotane levels during the day and the influence of a single morning dose. DESIGN A prospective case-control study was conducted to investigate the variation in plasma mitotane levels. METHODS Patients who had been treated for at least 24 weeks and had reached the therapeutic plasma level (14 mg/l) at least once were eligible. In the first group, mitotane levels were determined hourly for the duration of 8 h after administration of a single morning dose. In the second group, mitotane levels were assessed similarly without administration of a morning dose. RESULTS Ten patients were included in this study, and three patients participated in both groups. Median plasma level at baseline was 16.2 mg/l (range 11.3-23.3 mg/l) in the first group (n=7) and 17.0 mg/l (13.7-23.8) in the second group (n=6). Plasma levels displayed a median increase compared with baseline of 24% (range 6-42%) at t=4 after morning dose and a change of 13% (range -14 to 33%) at t=4 without morning dose (P=0.02). CONCLUSION A substantial increase in mitotane plasma levels was observed in steady-state patients within a period of 8 h after morning dosing. Without morning dose, mitotane curves showed a variable profile throughout the day. This implies that random sampling could yield incidentally high levels. For this reason, we recommend early-morning trough sampling as standard management in monitoring mitotane treatment.
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Affiliation(s)
- T M A Kerkhofs
- Department of Internal MedicineMáxima Medical Center, Ds. Th. Fliednerstraat 1, Eindhoven/Veldhoven 5631, The NetherlandsDepartment of Clinical PharmacologyMáxima Medical Center, Eindhoven/Veldhoven, The NetherlandsSection EndocrinologyDepartment of Internal Medicine, VU Medical Center, Vrije Universiteit Amsterdam, Amsterdam, The NetherlandsDepartment of Clinical Pharmacy and ToxicologyMaastricht University Medical Center+, Maastricht, The NetherlandsDepartment of Health Services Research and CAPHRI School for Public Health and Primary CareMaastricht University, Maastricht, The NetherlandsDepartments of Clinical OncologyClinical Pharmacy and ToxicologyLeiden University Medical Center, Leiden, The NetherlandsDivision of General Internal MedicineDepartment of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - L J J Derijks
- Department of Internal MedicineMáxima Medical Center, Ds. Th. Fliednerstraat 1, Eindhoven/Veldhoven 5631, The NetherlandsDepartment of Clinical PharmacologyMáxima Medical Center, Eindhoven/Veldhoven, The NetherlandsSection EndocrinologyDepartment of Internal Medicine, VU Medical Center, Vrije Universiteit Amsterdam, Amsterdam, The NetherlandsDepartment of Clinical Pharmacy and ToxicologyMaastricht University Medical Center+, Maastricht, The NetherlandsDepartment of Health Services Research and CAPHRI School for Public Health and Primary CareMaastricht University, Maastricht, The NetherlandsDepartments of Clinical OncologyClinical Pharmacy and ToxicologyLeiden University Medical Center, Leiden, The NetherlandsDivision of General Internal MedicineDepartment of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - M H T Ettaieb
- Department of Internal MedicineMáxima Medical Center, Ds. Th. Fliednerstraat 1, Eindhoven/Veldhoven 5631, The NetherlandsDepartment of Clinical PharmacologyMáxima Medical Center, Eindhoven/Veldhoven, The NetherlandsSection EndocrinologyDepartment of Internal Medicine, VU Medical Center, Vrije Universiteit Amsterdam, Amsterdam, The NetherlandsDepartment of Clinical Pharmacy and ToxicologyMaastricht University Medical Center+, Maastricht, The NetherlandsDepartment of Health Services Research and CAPHRI School for Public Health and Primary CareMaastricht University, Maastricht, The NetherlandsDepartments of Clinical OncologyClinical Pharmacy and ToxicologyLeiden University Medical Center, Leiden, The NetherlandsDivision of General Internal MedicineDepartment of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - E M W Eekhoff
- Department of Internal MedicineMáxima Medical Center, Ds. Th. Fliednerstraat 1, Eindhoven/Veldhoven 5631, The NetherlandsDepartment of Clinical PharmacologyMáxima Medical Center, Eindhoven/Veldhoven, The NetherlandsSection EndocrinologyDepartment of Internal Medicine, VU Medical Center, Vrije Universiteit Amsterdam, Amsterdam, The NetherlandsDepartment of Clinical Pharmacy and ToxicologyMaastricht University Medical Center+, Maastricht, The NetherlandsDepartment of Health Services Research and CAPHRI School for Public Health and Primary CareMaastricht University, Maastricht, The NetherlandsDepartments of Clinical OncologyClinical Pharmacy and ToxicologyLeiden University Medical Center, Leiden, The NetherlandsDivision of General Internal MedicineDepartment of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - C Neef
- Department of Internal MedicineMáxima Medical Center, Ds. Th. Fliednerstraat 1, Eindhoven/Veldhoven 5631, The NetherlandsDepartment of Clinical PharmacologyMáxima Medical Center, Eindhoven/Veldhoven, The NetherlandsSection EndocrinologyDepartment of Internal Medicine, VU Medical Center, Vrije Universiteit Amsterdam, Amsterdam, The NetherlandsDepartment of Clinical Pharmacy and ToxicologyMaastricht University Medical Center+, Maastricht, The NetherlandsDepartment of Health Services Research and CAPHRI School for Public Health and Primary CareMaastricht University, Maastricht, The NetherlandsDepartments of Clinical OncologyClinical Pharmacy and ToxicologyLeiden University Medical Center, Leiden, The NetherlandsDivision of General Internal MedicineDepartment of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands Department of Internal MedicineMáxima Medical Center, Ds. Th. Fliednerstraat 1, Eindhoven/Veldhoven 5631, The NetherlandsDepartment of Clinical PharmacologyMáxima Medical Center, Eindhoven/Veldhoven, The NetherlandsSection EndocrinologyDepartment of Internal Medicine, VU Medical Center, Vrije Universiteit Amsterdam, Amsterdam, The NetherlandsDepartment of Clinical Pharmacy and ToxicologyMaastricht University Medical Center+, Maastricht, The NetherlandsDepartment of Health Services Research and CAPHRI School for Public Health and Primary CareMaastricht University, Maastricht, The NetherlandsDepartments of Clinical OncologyClinical Pharmacy and ToxicologyLeiden University Medical Center, Leiden, The NetherlandsDivision of General Internal MedicineDepartment of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - H Gelderblom
- Department of Internal MedicineMáxima Medical Center, Ds. Th. Fliednerstraat 1, Eindhoven/Veldhoven 5631, The NetherlandsDepartment of Clinical PharmacologyMáxima Medical Center, Eindhoven/Veldhoven, The NetherlandsSection EndocrinologyDepartment of Internal Medicine, VU Medical Center, Vrije Universiteit Amsterdam, Amsterdam, The NetherlandsDepartment of Clinical Pharmacy and ToxicologyMaastricht University Medical Center+, Maastricht, The NetherlandsDepartment of Health Services Research and CAPHRI School for Public Health and Primary CareMaastricht University, Maastricht, The NetherlandsDepartments of Clinical OncologyClinical Pharmacy and ToxicologyLeiden University Medical Center, Leiden, The NetherlandsDivision of General Internal MedicineDepartment of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - J den Hartigh
- Department of Internal MedicineMáxima Medical Center, Ds. Th. Fliednerstraat 1, Eindhoven/Veldhoven 5631, The NetherlandsDepartment of Clinical PharmacologyMáxima Medical Center, Eindhoven/Veldhoven, The NetherlandsSection EndocrinologyDepartment of Internal Medicine, VU Medical Center, Vrije Universiteit Amsterdam, Amsterdam, The NetherlandsDepartment of Clinical Pharmacy and ToxicologyMaastricht University Medical Center+, Maastricht, The NetherlandsDepartment of Health Services Research and CAPHRI School for Public Health and Primary CareMaastricht University, Maastricht, The NetherlandsDepartments of Clinical OncologyClinical Pharmacy and ToxicologyLeiden University Medical Center, Leiden, The NetherlandsDivision of General Internal MedicineDepartment of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - H J Guchelaar
- Department of Internal MedicineMáxima Medical Center, Ds. Th. Fliednerstraat 1, Eindhoven/Veldhoven 5631, The NetherlandsDepartment of Clinical PharmacologyMáxima Medical Center, Eindhoven/Veldhoven, The NetherlandsSection EndocrinologyDepartment of Internal Medicine, VU Medical Center, Vrije Universiteit Amsterdam, Amsterdam, The NetherlandsDepartment of Clinical Pharmacy and ToxicologyMaastricht University Medical Center+, Maastricht, The NetherlandsDepartment of Health Services Research and CAPHRI School for Public Health and Primary CareMaastricht University, Maastricht, The NetherlandsDepartments of Clinical OncologyClinical Pharmacy and ToxicologyLeiden University Medical Center, Leiden, The NetherlandsDivision of General Internal MedicineDepartment of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - H R Haak
- Department of Internal MedicineMáxima Medical Center, Ds. Th. Fliednerstraat 1, Eindhoven/Veldhoven 5631, The NetherlandsDepartment of Clinical PharmacologyMáxima Medical Center, Eindhoven/Veldhoven, The NetherlandsSection EndocrinologyDepartment of Internal Medicine, VU Medical Center, Vrije Universiteit Amsterdam, Amsterdam, The NetherlandsDepartment of Clinical Pharmacy and ToxicologyMaastricht University Medical Center+, Maastricht, The NetherlandsDepartment of Health Services Research and CAPHRI School for Public Health and Primary CareMaastricht University, Maastricht, The NetherlandsDepartments of Clinical OncologyClinical Pharmacy and ToxicologyLeiden University Medical Center, Leiden, The NetherlandsDivision of General Internal MedicineDepartment of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands Department of Internal MedicineMáxima Medical Center, Ds. Th. Fliednerstraat 1, Eindhoven/Veldhoven 5631, The NetherlandsDepartment of Clinical PharmacologyMáxima Medical Center, Eindhoven/Veldhoven, The NetherlandsSection EndocrinologyDepartment of Internal Medicine, VU Medical Center, Vrije Universiteit Amsterdam, Amsterdam, The NetherlandsDepartment of Clinical Pharmacy and ToxicologyMaastricht University Medical Center+, Maastricht, The NetherlandsDepartment of Health Services Research and CAPHRI School for Public Health and Primary CareMaastricht University, Maastricht, The NetherlandsDepartments of Clinical OncologyClinical Pharmacy and ToxicologyLeiden University Medical Center, Leiden, The NetherlandsDivision of General Internal MedicineDepartment of Internal Medicine, Maastricht University Medical Centre+, Maastricht, The Netherlands Department of Internal MedicineMáxima Medical Center, Ds. Th. Fliednerstraat 1, Eindhoven/Veldhoven 5631, The NetherlandsDepartment of Clinical PharmacologyMáxima Medical Center, Eindhoven/Veldhoven, The NetherlandsSection EndocrinologyDepartment of Internal Medicine, VU Medical Cent
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Moes D, Bent S, Swen J, van der Straaten T, Verspaget H, Guchelaar H, den Hartigh J, van Hoek B. Population pharmacokinetics and pharmacogenetics of once daily tacrolimus formulation (Advagraf®) in liver transplant patients. Transpl Immunol 2014. [DOI: 10.1016/j.trim.2014.11.123] [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: 11/28/2022]
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van Iersel LBJ, de Leede EM, Vahrmeijer AL, Tijl FGJ, den Hartigh J, Kuppen PJK, Hartgrink HH, Gelderblom H, Nortier JWR, Tollenaar RAEM, van de Velde CJH. Isolated hepatic perfusion with oxaliplatin combined with 100 mg melphalan in patients with metastases confined to the liver: A phase I study. Eur J Surg Oncol 2014; 40:1557-63. [PMID: 25125340 DOI: 10.1016/j.ejso.2014.06.010] [Citation(s) in RCA: 14] [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] [Received: 02/28/2014] [Revised: 06/18/2014] [Accepted: 06/26/2014] [Indexed: 12/31/2022] Open
Abstract
AIM To improve isolated hepatic perfusion (IHP), we performed a phase I dose-escalation study to determine the optimal oxaliplatin dose in combination with a fixed melphalan dose. METHODS Between June 2007 and July 2008, 11 patients, comprising of 8 colorectal cancer and 3 uveal melanoma patients and all with isolated liver metastases, were treated with a one hour IHP with escalating doses of oxaliplatin combined with 100 mg melphalan. Samples of blood and perfusate were taken during IHP treatment for pharmacokinetic analysis of both drugs and patients were monitored for toxicity, response and survival. RESULTS Dose limiting sinusoidal obstruction syndrome (SOS) occurred at 150 mg oxaliplatin. The areas under the concentration-time curves (AUC) of oxaliplatin at the maximal tolerated dose (MTD) of 100 mg oxaliplatin ranged from 11.9 mg/L h to 16.5 mg/L h. All 4 patients treated at the MTD showed progressive disease 3 months after IHP. CONCLUSIONS In view of similar and even higher doses of oxaliplatin applied in both systemic treatment and hepatic artery infusion (HAI), applying this dose in IHP is not expected to improve treatment results in patients with isolated hepatic metastases.
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Affiliation(s)
- L B J van Iersel
- Department of Clinical Oncology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - E M de Leede
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - A L Vahrmeijer
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - F G J Tijl
- Department of Extra Corporal Circulation, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - J den Hartigh
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - P J K Kuppen
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - H H Hartgrink
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - H Gelderblom
- Department of Clinical Oncology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - J W R Nortier
- Department of Clinical Oncology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - R A E M Tollenaar
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - C J H van de Velde
- Department of Surgery, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands.
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de Wit D, Gelderblom H, Sparreboom A, den Hartigh J, den Hollander M, König-Quartel JMC, Hessing T, Guchelaar HJ, van Erp NP. Midazolam as a phenotyping probe to predict sunitinib exposure in patients with cancer. Cancer Chemother Pharmacol 2013; 73:87-96. [DOI: 10.1007/s00280-013-2322-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 10/09/2013] [Indexed: 12/28/2022]
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Opdam FL, Dezentje VO, den Hartigh J, Modak AS, Vree R, Batman E, Smorenburg CH, Nortier JWR, Gelderblom H, Guchelaar HJ. Erratum to: The use of the 13C-dextromethorphan breath test for phenotyping CYP2D6 in breast cancer patients using tamoxifen: association with CYP2D6 genotype and serum endoxifen levels. Cancer Chemother Pharmacol 2013. [DOI: 10.1007/s00280-012-2065-x] [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: 11/28/2022]
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Daleboudt GMN, Reinders MEJ, Hartigh JD, Huizinga TWJ, Rabelink AJ, de Fijter JW, Berger SP. Concentration-controlled treatment of lupus nephritis with mycophenolate mofetil. Lupus 2012; 22:171-9. [DOI: 10.1177/0961203312469261] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Background: Mycophenolate mofetil (MMF) has recently been established as a potent drug in maintenance treatment for lupus nephritis. However, there is no consensus on the optimal dosing regimen because of a high inter-individual variability of mycophenolic acid (MPA), the active metabolite of MMF. This retrospective study aimed to investigate the effect of an individualized dosing regimen through concentration-controlled treatment on MPA exposure and renal outcome in patients with lupus nephritis. Methods: Sixteen patients with lupus nephritis and treatment with low-dose intravenous cyclophosphamide followed by MMF were included. MPA area under the plasma concentration-time curve from 0 to 12 hours (MPA-AUC0–12) was assessed within a month after MMF initiation. After determination of MPA-AUC0–12, MMF doses were titrated to achieve a target MPA-AUC0–12 of 60–90 mg*h/l. After on average six months, MPA-AUC0–12 measures were repeated to assess the effect of dose adjustment. Results: One month after introducing MMF, MPA-AUC0–12 was low and showed a high inter-individual variability. Dose adjustment with a target MPA-AUC0–12 of 60–90 mg*h/l resulted in individualized MMF dosing, significantly higher MPA-AUC0–12 levels, and a non-significant reduction in variability of MPA-AUC0–12. Adverse effects were reported by 37.5% of patients, which resulted in a switch to azathioprine in two patients. There was no significant relationship between the occurrence of adverse effects and MPA-AUC0–12. At 12 months of follow-up 87.5% of patients had achieved either partial (18.7%) or complete (68.8%) remission. Conclusion: Concentration-controlled dose adjustments with a target MPA-AUC0–12 of 60–90 mg*h/l was associated with optimized MPA exposure and an excellent renal outcome at 12 months of follow-up in a small sample of SLE patients with lupus nephritis.
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Affiliation(s)
- GMN Daleboudt
- Department of Nephrology, Leiden University Medical Center, The Netherlands
| | - MEJ Reinders
- Department of Nephrology, Leiden University Medical Center, The Netherlands
| | - J den Hartigh
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, The Netherlands
| | - TWJ Huizinga
- Department of Rheumatology, Leiden University Medical Center, The Netherlands
| | - AJ Rabelink
- Department of Nephrology, Leiden University Medical Center, The Netherlands
| | - JW de Fijter
- Department of Nephrology, Leiden University Medical Center, The Netherlands
| | - SP Berger
- Department of Nephrology, Leiden University Medical Center, The Netherlands
- Department of Internal Medicine, Erasmus Medical Center, The Netherlands
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12
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Dezentje VO, den Hartigh J, Guchelaar H, Hessing T, van der Straaten T, Vletter - Bogaartz JM, Vree R, Maartense E, Smorenburg CH, Putter H, Dieudonné A, Neven P, Nortier JWR, Gelderblom H. Association between endoxifen serum concentration and predicted CYP2D6 phenotype in a prospective cohort of patients with early-stage breast cancer. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.562] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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13
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Welzen MEB, Dezentje VO, van Schaik RHN, Colbers EPH, Guchelaar H, den Hartigh J, Burger DM, Van Laarhoven H. The effect of a tamoxifen dose increase from 20 mg to 40 mg in patients with at least one inactive CYP2D6 variant allele and/or concomitant use of a CYP2D6 inhibitor. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.584] [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: 11/20/2022] Open
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14
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ten Brink MH, Wessels JA, Hartigh JD, van der Straaten T, von dem Borne PA, Guchelaar HJ, Zwaveling J. Effect of genetic polymorphisms in genes encoding GST isoenzymes on BU pharmacokinetics in adult patients undergoing hematopoietic SCT. Bone Marrow Transplant 2011; 47:190-5. [DOI: 10.1038/bmt.2011.55] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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15
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van Nieuwkoop C, den Exter P, Elzevier H, den Hartigh J, van Dissel J. Intravesical gentamicin for recurrent urinary tract infection in patients with intermittent bladder catheterisation. Int J Antimicrob Agents 2010; 36:485-90. [DOI: 10.1016/j.ijantimicag.2010.05.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Revised: 05/10/2010] [Accepted: 05/18/2010] [Indexed: 11/29/2022]
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17
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Zuurman L, Roy C, Schoemaker RC, Hazekamp A, den Hartigh J, Bender JCME, Verpoorte R, Pinquier JL, Cohen AF, van Gerven JMA. Effect of intrapulmonary tetrahydrocannabinol administration in humans. J Psychopharmacol 2008; 22:707-16. [PMID: 18515447 DOI: 10.1177/0269881108089581] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This randomised, double-blind, placebo-controlled, cross-over study was designed to identify which pharmacodynamic parameters most accurately quantify the effects of delta-9-Tetrahydrocannabinol (THC), the predominantly psychoactive component of cannabis. In addition, we investigated the acceptability and usefulness of a novel mode of intrapulmonary THC administration using a Volcano vaporizer and pure THC instead of cannabis. Rising doses of THC (2, 4, 6 and 8 mg) or vehicle were administered with 90 minutes intervals to twelve healthy males using a Volcano vaporizer. Very low between-subject variability was observed in THC plasma concentrations, characterising the Volcano vaporizer as a suitable method for the administration of THC. Heart rate showed a sharp increase and rapid decline after each THC administration (8 mg: 19.4 bpm: 95% CI 13.2, 25.5). By contrast, dose dependent effects of body sway (8 mg: 108.5%: 95% CI 72.2%, 152.4%) and different subjective parameters did not return to baseline between doses (Visual Analogue Scales of 'alertness' (8 mg: -33.6 mm: 95% CI -41.6, -25.7), 'feeling high' (8 mg: 1.09 U: 95% CI 0.85, 1.33), 'external perception' (8 mg: 0.62 U: 95% CI 0.37, 0.86)). PK/PD-modeling of heart rate displayed a relatively short equilibration half-life of 7.68 min. CNS parameters showed equilibration half-lives ranging between 39.4 - 84.2 min. Some EEG-frequency bands, and pupil size showed small changes following the highest dose of THC. No changes were seen in saccadic eye movements, smooth pursuit and adaptive tracking performance. These results may be applicable in the development of novel cannabinoid agonists and antagonists, and in studies of the pharmacology and physiology of cannabinoid systems in humans.
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Affiliation(s)
- L Zuurman
- Centre for Human Drug Research, Pharmacology CNS, Leiden, The Netherlands.
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18
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den Hartigh J, Voortman G, van Oort WJ, Weenen H, Pinedo HM. Handling of biological samples in the determination of the anti-neoplastic drug mitomycin C. J Pharm Biomed Anal 2008; 3:417-23. [PMID: 16867653 DOI: 10.1016/0731-7085(85)80055-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/1984] [Revised: 08/16/1984] [Indexed: 11/30/2022]
Abstract
A study to ascertain suitable conditions for handling biological samples from patients, treated with the antibiotic mitomycin C (MMC), with the objective of improving the accuracy and reliability of the determination is described. Situations frequently occurring in medical practice are simulated to optimize procedures for reliable and reproducible sampling, sample treatment and determination of MMC. Continuation of drug partitioning in whole blood after sampling can be prevented by immediate cooling in ice before the separation of plasma from cells. The adjustment of the pH of urine samples is shown to be particularly important since a low urinary pH causes decomposition of MMC; moreover, it may decrease extraction recovery. Furthermore, long-term exposure of samples to daylight induces drug decomposition. Frozen storage of plasma and urine samples for periods greater than 3 weeks is to be avoided as this results in a considerable drop in MMC concentration. Repeated cycles of freezing and thawing are shown to have no effect upon the analytical results (6 cycles tested). The analysis of extracts of biological samples may take place up to at least 24 h after their preparation without measurable loss of analyte.
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Affiliation(s)
- J den Hartigh
- Department of Analytical Pharmacy, Faculty of Pharmacy, State University of Utrecht, Catharijnesingel 60, 3511 GH, Utrecht, The Netherlands
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19
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Willemze AJ, Cremers SC, Schoemaker RC, Lankester AC, den Hartigh J, Burggraaf J, Vossen JM. Ciclosporin kinetics in children after stem cell transplantation. Br J Clin Pharmacol 2008; 66:539-45. [PMID: 18492124 DOI: 10.1111/j.1365-2125.2008.03217.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
AIMS To develop a limited sampling strategy to determine ciclosporin systemic exposure [area-under-the-curve(AUC)]. This is meant to be the first step in a future study of the relationship between AUC and the biological effects of ciclosporin. METHODS The pharmacokinetics of ciclosporin was investigated prospectively following stem cell transplantation (SCT) in 17 children, aged 1.8-16.1 years. Ciclosporin was given twice daily, intravenously over a short infusion of 2 h duration during the early post-SCT period, or orally later on, when oral medication was well tolerated. Parameter estimation was performed using nonlinear mixed effect modelling as implemented in the NONMEM program. Individual empirical Bayes estimates of clearance and distribution volume were correlated with the demographic variables. RESULTS Pharmacokinetics was described adequately with a two-compartment model with lag time (population estimates: CL = 11.3 l h(-1); V(c) = 16.5 l; V(p) = 59.9 l; t(1/2) absorption = 0.78 h, t(lag) = 0.6 h). The AUCs, determined for the combination of trough level with one time point between 2 and 3 h after dosing, correlated very well with the reference AUC (r(2) = 0.97). No correlation was found between clearance and distribution volume, and the demographic patient variables length, body weight, age and glomerular filtration rate. CONCLUSION A two-point limited sampling strategy, in combination with a Bayesian fitting procedure using the pharmacokinetic population model described, can adequately determine the AUC of ciclosporin. Since no correlation between clearance and body weight was found, dosing ciclosporin per kg bodyweight is not supported by the results of this study. We suggest starting with a fixed dose, followed by AUC determination and dose adjustment.
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Affiliation(s)
- A J Willemze
- Department of Paediatrics, Division of Immunology, Haematology, Oncology and Bone Marrow Transplantation and Autoimmune Diseases, Leiden University Medical Centre, Leiden, The Netherlands.
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20
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Bartelink IH, Bredius RGM, Ververs TT, Raphael MF, van Kesteren C, Bierings M, Rademaker CMA, den Hartigh J, Uiterwaal CSPM, Zwaveling J, Boelens JJ. Once-daily intravenous busulfan with therapeutic drug monitoring compared to conventional oral busulfan improves survival and engraftment in children undergoing allogeneic stem cell transplantation. Biol Blood Marrow Transplant 2008; 14:88-98. [PMID: 18158965 DOI: 10.1016/j.bbmt.2007.09.015] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2007] [Accepted: 09/24/2007] [Indexed: 11/25/2022]
Abstract
Because of intra- and interindividual variability, bioavailability, and pharmacokinetics of busulfan (Bu) in children, oral busulfan without therapeutic drug monitoring (TDM) is assumed to be associated with higher graft failure rates as well as higher toxicity (eg, veno-occlusive disease [VOD]). This study compares the outcome of hematopoietic stem cell transplantation (HSCT) of 2 groups: 1) 30 patients who received myeloablation with once-daily intravenous (i.v.) dose-targeted busulfan (BUdtIV) based on TDM and 2) 30 patients who received the current practice of untargeted oral busulfan (BUPO). Patients received a 3-hour infusion of Bu at a first dose of 120 mg/m(2) (age >or=1 year) or 80 mg/m(2) (<1 year), or BUPO 1 mg/kg 4 times daily. Both regimens were continued for 4 days. The target area under the curve (AUC) was defined as 17,500 microg *h/l. BUdtIV resulted in higher event-free survival (EFS) and survival rates compared to BUPO (EFS: 30% versus 83%, P < .001, survival: 53% versus 83%, P = .016). BUdtIV was associated with more cases of VOD. TDM was feasible in routine clinical practice. The results show that i.v. Bu using TDM is preferable over oral Bu in children undergoing allogeneic stem cell transplantation, especially in those at high risk for graft failure/relapse.
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Affiliation(s)
- Imke H Bartelink
- Department of Hematology, University Medical Center Utrecht, the Netherlands.
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21
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Langers P, Cremers SCLM, den Hartigh J, Rijnbeek EMT, Ringers J, Lamers CBHW, Hommes DW, van Hoek B. Individualized population pharmacokinetic model with limited sampling for cyclosporine monitoring after liver transplantation in clinical practice. Aliment Pharmacol Ther 2007; 26:1447-54. [PMID: 17848182 DOI: 10.1111/j.1365-2036.2007.03514.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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
BACKGROUND We recently developed and validated limited sampling models (LSMs) for cyclosporine monitoring after orthotopic liver transplantation based on individualized population pharmacokinetic models with Bayesian modelling. Aim To evaluate LSM in practice, and to seek optimal balance between benefit and discomfort. METHODS In 30 stable patients, more than 6 months after orthotopic liver transplantation, previously switched from trough- to 2 h post-dose (C2)-monitoring, we switched to 3-monthly LSM 0,1,2,3 h-monitoring. During 18 months we evaluated dose, creatinine clearance, calculated area under the curve, intra-patient pharmacokinetic variability and ability to assess systemic exposure by several previously validated LSMs. RESULTS Within patients, there was variability of cyclosporine-area under the curve with the same dose (CV of 15%). Compared to C2-monitoring, there was no significant difference in dose (P = 0.237), creatinine clearance (P = 0.071) and number of rejections. Some models showed excellent correlation and precision with LSM 0,1,2,3 h comparing area under the curves (0,2 h: r(2) = 0.88; 0,1,3 h: r(2) = 0.91; 0,2,3 h: r(2) = 0.92, all P < 0.001) with no difference in advised dose. CONCLUSIONS The limited sampling model, with only trough- and 2-h sampling, yields excellent accuracy and assesses systemic exposure much better than C2 with less bias and greater precision. Considering the calculated intra-patient variability, more precision is redundant, so LSM 0,2 h seems the optimal way of cyclosporine-monitoring.
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Affiliation(s)
- P Langers
- Department of Gastroenterology, Leiden University Medical Center, Leiden, The Netherlands
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22
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Zwaveling J, Bredius RGM, Cremers SCLM, Ball LM, Lankester AC, Teepe-Twiss IM, Egeler RM, den Hartigh J, Vossen JM. Intravenous busulfan in children prior to stem cell transplantation: study of pharmacokinetics in association with early clinical outcome and toxicity. Bone Marrow Transplant 2005; 35:17-23. [PMID: 15502853 DOI: 10.1038/sj.bmt.1704707] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We studied the pharmacokinetics of intravenous busulfan (Bu) in children in order to further optimize intravenous Bu dosing in relation to toxicity and survival. A total of 31 children undergoing Bu-based conditioning for allogeneic SCT were enrolled in a study. The starting dose was 1.0 mg/kg (age < 4 years) and 0.8 mg/kg (age > or =4 years), four doses per day during 4 days. Dose adjustment was allowed up to a maximum dose of 1.0 mg/kg per dose if the target area under the serum concentration-time curve (AUC) was not reached. Pharmacokinetic studies were performed after the first dose. Donor engraftment was established in 28 out of 31 patients. The average AUC after the first dose was the same in children < 4 years as in children > or =4 years. Mean clearance was higher in children < 4 years than in children > or =4 years. In 35% of all patients, total AUC was within the target AUC. The other children's AUCs were below the target range. No relationships were found between systemic exposure to Bu and toxicity or clinical outcome. We concluded that, in accordance with previous data, within the observed AUCs no clear relationship was observed between Bu AUC and outcome with respect to toxicity, engraftment and relapse.
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Affiliation(s)
- J Zwaveling
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands.
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23
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Langers P, Cremers SCLM, den Hartigh J, Rijnbeek EMT, Ringers J, Lamers CBHW, van Hoek B. Easy-to-use, accurate and flexible individualized Bayesian limited sampling method without fixed time points for ciclosporin monitoring after liver transplantation. Aliment Pharmacol Ther 2005; 21:549-57. [PMID: 15740538 DOI: 10.1111/j.1365-2036.2005.02364.x] [Citation(s) in RCA: 9] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND New methods to estimate the systemic exposure to ciclosporin such as the level 2 h after dosing and limited sampling formulas may lead to improved clinical outcome after orthotopic liver transplantation. However, most strategies are characterized by rigid sampling times. AIM To develop and validate a flexible individualized population-pharmacokinetic model for ciclosporin monitoring in orthotopic liver transplantation. METHODS A total of 62 curves obtained from 31 patients at least 0.5 year after orthotopic liver transplantation were divided into two equal groups. From 31 curves, relatively simple limited sampling formulas were derived using multiple regression analysis, while using pharmacokinetic software a two-compartment population-pharmacokinetic model was derived from these same data. We then tested the ability to estimate the AUC by the limited sampling formulas and a different approach using several limited sampling strategies on the other 31 curves. The new approach consists of individualizing the mean a priori population-pharmacokinetic parameters of the two-compartment population-pharmacokinetic model by means of maximum a posteriori Bayesian fitting with individual data leading to an individualized population-pharmacokinetic limited sampling model. From the individualized pharmacokinetic parameters, AUC(0-12h) was calculated for each combination of measured blood concentrations. The calculated AUC(0-12h) both from the limited-sampling formulas and the limited-sampling model were compared with the gold standard AUC(0-12h) (trapezoidal rule) by Pearson's correlation coefficient and prediction precision and bias were calculated. RESULTS The AUC(0-12h) value calculated by individualizing the population-pharmacokinetic model using several combinations of measured blood concentrations: 0 + 2 h (r(2) = 0.94), 0 + 1 + 2 h (r(2) = 0.94), 0 + 1 + 3 h (r(2) = 0.92), 0 + 2 + 3 h (r(2) = 0.92) and 0 + 1 + 2 + 3 h (r(2) = 0.96) had excellent correlation with AUC(0-12h), better than limited sampling formulas with less than three sampling time points. Even trough level with limited sampling method (r(2) = 0.86) correlated better than the level after 2 h of dosing (r(2) = 0.75) or trough level (r(2) = 0.64) as single values without limited sampling method. Moreover, the individualized population-pharmacokinetic model had a low prediction bias and excellent precision. CONCLUSION Multiple rigid sampling time points limit the use of limited sampling formulas. The major advantage of the Bayesian estimation approach presented here, is that blood sampling time points are not fixed, as long as sampling time is known. The predictive performance of this new approach is superior to trough level and that after 2 h of dosing and at least as good as limited sampling formulas. It is of clear advantage in busy out-patient clinics.
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Affiliation(s)
- P Langers
- Department of Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, The Netherlands
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24
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Twiss IM, Burggraaf J, Schoemaker RC, van Elburg RM, den Hartigh J, Cohen AF, Vermeij P. The sugar absorption test in the evaluation of the gastrointestinal intolerance to bisphosphonates: studies with oral pamidronate. Clin Pharmacol Ther 2001; 69:431-7. [PMID: 11406740 DOI: 10.1067/mcp.2001.115724] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
UNLABELLED RATIONALE AND AIMS Some bisphosphonates induce gastrointestinal side effects, but the localization in the gastrointestinal tract and the underlying mechanism are unknown. The feasibility of the sugar absorption test was investigated to assess the gastrointestinal effects of oral enteric-coated pamidronate. The sugar absorption test measures the urinary excretion of lactulose, mannitol, and sucrose after oral intake. Increases in the lactulose/mannitol ratio and sucrose excretion indicate increased small intestinal permeability and gastroduodenal disease, respectively. SUBJECTS AND METHODS Twelve volunteers (5 women and 7 men) participated in a randomized, double-blind, 4-way crossover study. The sugar absorption test was performed 2 hours after the final drug intake following a 3-day course of enteric-coated pamidronate (300 mg daily), placebo, or acetylsalicylic acid (3 g daily). The lactulose/mannitol ratio and sucrose excretion were measured in urine collected for 5 hours after ingestion of the solution. The fourth treatment consisted of intravenous administration of pamidronate. Treatment comparison was with paired t tests after log-transformation. RESULTS The lactulose/mannitol ratio after pamidronate and acetylsalicylic acid administration was 54% and 118% higher than that after placebo (95% confidence intervals [CI], +8%, +119%, and +69%, +182%). The lactulose/mannitol ratio after pamidronate administration was 29% lower (95% CI, -54%, +3%) than that after acetylsalicylic acid. Compared with placebo the sucrose excretion was 290% higher after acetylsalicylic acid (95% CI, +46%, +518%) but only 8% higher after pamidronate (95% CI, -41%, +97%). The absorption of pamidronate was below 1%, and there was no relationship with the increased lactulose/mannitol ratio. CONCLUSION Oral enteric-coated pamidronate increases intestinal but not gastroduodenal permeability. There was no relationship between intestinal permeability and absorption of pamidronate. It appears that the sugar absorption test is an appropriate, noninvasive method for evaluation of gastrointestinal effects of bisphosphonates in humans.
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Affiliation(s)
- I M Twiss
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, Leiden, The Netherlands.
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25
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van der Vorst MM, Ruys-Dudok van Heel I, Kist-van Holthe JE, den Hartigh J, Schoemaker RC, Cohen AF, Burggraaf J. Continuous intravenous furosemide in haemodynamically unstable children after cardiac surgery. Intensive Care Med 2001; 27:711-5. [PMID: 11398698 DOI: 10.1007/s001340000819] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [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: 10/27/2022]
Abstract
OBJECTIVE The commonly used continuous intravenous (i.v.) furosemide dosing schedule after cardiac surgery in children is largely empirical and may not be optimal. This may even be more marked in children after cardiac surgery who are haemodynamically unstable, and in whom transient renal insufficiency may occur. A study was performed to obtain an impression regarding which clinically applicable measures may be used to design a rational scheme for continuous i.v. furosemide therapy in children after cardiac surgery. SUBJECTS AND METHODS Twelve paediatric patients (5F/7 M, age 0-33 weeks) post-cardiac surgery, who were to receive 3 days of continuous i.v. furosemide treatment, were included in an open study. Blood and urine samples were taken for furosemide, creatinine, and electrolyte levels, and fractionated urinary output was measured. Furosemide in blood and urine was measured using high performance liquid chromatography (HPLC). RESULTS The mean starting dose of continuous i.v. furosemide was 0.093 (+/- 0.016) mg/kg per hour. The mean dose was increased to 0.175 (+/- 0.045) mg/kg per hour per hour on day 2, and changed to 0.150 (+/- 0.052) mg/kg per hour on day 3. Infusion rates were increased from day 1 to day 2 in ten cases, and decreased from day 2 to day 3 in three cases. Serum furosemide levels never exceeded ototoxic levels. The urinary furosemide excretion rate was inversely related to serum creatinine levels. CONCLUSIONS This study extends the observation of the beneficial effects of continuous i.v. furosemide also to those children who are haemodynamically unstable after cardiac surgery. However, as the effects of furosemide are dependent on renal function, it can be hypothesised that the dosing schedule may be optimised. Contrary to the currently used dosage schedule in which the dose of furosemide is gradually increased over time, it may be more rational to start with a higher dose and adapt this dose (downward) guided by the observed effect (urine output). Because the infusion rate was increased to 0.2 mg/kg per hour in nine out of 12 patients on day 2 and was never increased further, this suggests that a starting rate of 0.2 mg/kg per hour may be optimal.
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Affiliation(s)
- M M van der Vorst
- Department of Paediatrics, Leiden University Medical Centre, PO Box 9600, 2300 Leiden, The Netherlands.
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26
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Schippers EF, Hugen PW, den Hartigh J, Burger DM, Hoetelmans RM, Visser LG, Kroon FP. No drug-drug interaction between nelfinavir or indinavir and mefloquine in HIV-1-infected patients. AIDS 2000; 14:2794-5. [PMID: 11125902 DOI: 10.1097/00002030-200012010-00023] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- E F Schippers
- Department of Infectious Diseases, Leiden University Medical Center, The Netherlands
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27
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Sarton E, Olofsen E, Romberg R, den Hartigh J, Kest B, Nieuwenhuijs D, Burm A, Teppema L, Dahan A. Sex differences in morphine analgesia: an experimental study in healthy volunteers. Anesthesiology 2000; 93:1245-54; discussion 6A. [PMID: 11046213 DOI: 10.1097/00000542-200011000-00018] [Citation(s) in RCA: 257] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Animal and human studies indicate the existence of important sex-related differences in opioid-mediated behavior. In this study the authors examined the influence of morphine on experimentally induced pain in healthy male and female volunteers. METHODS Young healthy men and women (10 of each sex) received intravenous morphine (bolus 0.1-mg/kg dose followed by an infusion of 0.030 mg. kg-1. h-1 for 1 h). Pain threshold and pain tolerance in response to a gradual increase in transcutaneous electrical stimulation, as well as plasma concentrations of morphine and its major metabolites (morphine-6-glucuronide and morphine-3-glucuronide) were determined at regular intervals up to 7 h after the start of morphine infusion. A population pharmacodynamic model was used to analyze the morphine-induced changes in stimulus intensity. The improvement of the model fits by inclusion of covariates (sex, age, weight, lean body mass) was tested for significance. The model is characterized by baseline current, a rate constant for equilibrium between plasma and effect-site morphine concentrations (ke0), and analgesic potency (AC50, or the morphine concentration causing a 100% increase in stimulus intensity for response). RESULTS The inclusion of the covariates age, weight, and lean body mass did not improve the model fits for any of the model parameters. For both pain threshold and tolerance, a significant dependency on sex was observed for the parameters ke0 (pain threshold: 0.0070 +/- 0.0013 (+/- SE) min-1 in men vs. 0.0030 +/- 0. 0005 min-1 in women; pain tolerance: 0.0073 +/- 0.0012 min-1 in men vs. 0.0024 +/- 0.0005 min-1 in women) and AC50 (pain threshold: 71.2 +/- 10.5 nm in men vs. 41.7 +/- 8.4 nm in women; pain tolerance: 76. 5 +/- 7.4 nm in men vs. 32.9 +/- 7.9 nm in women). Baseline currents were similar for both sexes: 21.4 +/- 1.6 mA for pain threshold and 39.1 +/- 2.3 mA for pain tolerance. Concentrations of morphine, morphine-3-glucuronide, and morphine-6-glucuronide did not differ between men and women. CONCLUSIONS These data show sex differences in morphine analgesia, with greater morphine potency but slower speed of onset and offset in women. The data are in agreement with observations of sex differences in morphine-induced respiratory depression and may explain higher postoperative opioid consumption in men relative to women.
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Affiliation(s)
- E Sarton
- Departments of Anesthesiology, Clinical Pharmacy and Toxicology, and Physiology, Leiden University Medical Center, Leiden, The Netherlands
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Franken KL, Hiemstra HS, van Meijgaarden KE, Subronto Y, den Hartigh J, Ottenhoff TH, Drijfhout JW. Purification of his-tagged proteins by immobilized chelate affinity chromatography: the benefits from the use of organic solvent. Protein Expr Purif 2000; 18:95-9. [PMID: 10648174 DOI: 10.1006/prep.1999.1162] [Citation(s) in RCA: 181] [Impact Index Per Article: 7.5] [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]
Abstract
Recombinant proteins overexpressed in and purified from Escherichia coli contain impurities that are toxic in biological assays. The application of affinity purification procedures is often not sufficient to remove these toxic components. We here describe a simple and fast, one-step protocol to remove these impurities highly efficiently. Four recombinant proteins were overexpressed in E. coli as His-tagged fusion proteins and purified by immobilized metal chelate affinity chromatography on Ni-NTA beads. Depending on the protein, the composition of the lysis buffer, and the washing protocol, various impurities appeared to be present in the purified protein preparations. Here we show how the use of 60% isopropanol during washing steps removed most of these contaminants from the end products. In addition to the removal of proteins that aspecifically adhere to the beads or to the tagged protein, this procedure was particularly useful in removing endotoxins. Moreover, we show that detergents such as NP-40, that are necessarily employed during lysis, are also efficiently removed. Finally, we show that proteins are able to refold correctly after isopropanol treatment. Thus, the resulting end products contain significantly less contaminating E. coli proteins, endotoxins, and detergents.
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Affiliation(s)
- K L Franken
- Department of Immunohematology and Blood Bank, Leiden University Medical Center, Leiden, 2300 RC, The Netherlands
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van den Besselaar AM, Bertina RM, van der Meer FJ, den Hartigh J. Different sensitivities of various thromboplastins to two blood collection systems for monitoring oral anticoagulant therapy. Thromb Haemost 1999; 82:153-4. [PMID: 10456474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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31
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Sparidans RW, den Hartigh J, Cremers S, Beijnen JH, Vermeij P. Semi-automatic liquid chromatographic analysis of pamidronate in urine after derivatization with 1-naphthylisothiocyanate. J Chromatogr B Biomed Sci Appl 1999; 730:95-9. [PMID: 10437676 DOI: 10.1016/s0378-4347(99)00196-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
An existing sensitive chromatographic assay for pamidronate in urine has considerably been automated. Using the same sample processor, the solid-phase extraction (SPE) was automated separately from the derivatization with 1-naphthylisothiocyanate, the two-fold ion-pair liquid-liquid-extraction and the treatment with hydrogen peroxide for the 2-20 ng/ml concentration range. The automatic procedure was preceded by a triple calcium precipitation and interrupted by evaporation of the SPE eluate under nitrogen. For the 0.5-5 microg/ml concentration range one automatic sequence was used by avoiding evaporation during the sample treatment. In addition to the labour-saving of the semi-automatic procedure, the daily sample-throughput was improved compared to the existing manual assay. Further, the validation showed marginal improvements in the precision, accuracy and lower limit of quantification.
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Affiliation(s)
- R W Sparidans
- Leiden University Medical Center, Department of Clinical Pharmacy and Toxicology, The Netherlands.
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32
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Abstract
Chromatographic analysis of bisphosphonates in the past has been based primarily on reversed-phase liquid chromatography (RPLC) and ion-exchange chromatography. Gas chromatography (GC) and recently even capillary electrophoresis have also been employed. For bioanalysis, pre-treatment of the sample is a major part of the analysis; protein precipitation, calcium precipitation, solid-phase extraction (SPE) and derivatization have demonstrated to play an important role in bisphosphonate assays. For some of these treatments, for example SPE and derivatization, automation may be possible. Derivatization is a prerequisite for GC analysis of bisphosphonates; a volatile derivative has to be formed. For liquid chromatography, two types of derivatization are known for bisphosphonates. First, the bisphosphonate side chain can be modified by a chemical reaction to yield a derivative with advantageous chromatographic and spectroscopic properties. Secondly, by complexation of both phosphonate groups or of phosphate after decomposition of the analyte, a coloured complex can be formed. The most sensitive bioanalytical methods are based on RPLC and fluorescence detection, if necessary after derivatization. If low detection limits are not required, for example for analysis of pharmaceutical preparations, non-specific detection methods can be applied.
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Affiliation(s)
- R W Sparidans
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Centre, The Netherlands
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33
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Kuijpers EA, den Hartigh J, Vermeij P. A stability study involving HPLC analysis of aqueous thiorphan solutions in the presence of human serum albumin. Pharm Dev Technol 1998; 3:185-92. [PMID: 9653755 DOI: 10.3109/10837459809028494] [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] [Indexed: 11/13/2022]
Abstract
The stability of thiorphan (1.0 mg/ml) in normal saline containing 1% human serum albumin (HSA) was determined in order to find the most appropriate storage conditions. Direct liquid chromatographic analysis of this solution was feasible through the use of a micellar chromatographic system and proved to be stability indicating. During 8 weeks the percentages of the initial thiorphan concentration remaining after storage at 4, 20, 30, and 50 degrees C were determined. An Arrhenius plot was composed using the rate constants of thiorphan degradation at these temperatures. The thiorphan solution was stable for at least 2 months if stored at -20 degrees C. Taking into account the oxidative degradation of about 7% after thawing, we determined that the solution can be kept in a refrigerator for 4 days. Storage at room temperature should be limited to 1 day. By identification of the degradation products it could be concluded that thiorphan is degraded mainly via oxidation forming disulfides. Therefore, it is recommended that the solvent be purged with nitrogen before thiorphan is dissolved.
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Affiliation(s)
- E A Kuijpers
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, The Netherlands
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34
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Sparidans RW, den Hartigh J, Beijnen JH, Vermeij P. Semi-automatic liquid chromatographic analysis of pamidronate in serum and citrate plasma after derivatization with 1-naphthylisothiocyanate. J Chromatogr B Biomed Sci Appl 1998; 705:331-9. [PMID: 9521572 DOI: 10.1016/s0378-4347(97)00507-0] [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: 02/06/2023]
Abstract
The semi-automatic method for the determination of the bisphosphonate pamidronate in serum and citrate plasma involves a manual protein precipitation with trichloroacetic acid and a manual coprecipitation of the bisphosphonate with calcium phosphate, followed by an automated solid-phase extraction on anion-exchange columns. After off-line evaporation of the extract under nitrogen and reconstitution in water, the automatic procedure is continued by automatic derivatization with 1-naphthylisothiocyanate, ion-pair liquid-liquid extraction and a treatment with hydrogen peroxide, prior to analysis by ion-pair HPLC and fluorescence detection at 285/390 nm. The intra- and inter-day precisions are 1.3 and 7%, respectively, for a standard of 100 ng ml(-1) pamidronate in serum; the average accuracy for this standard is 107%. The lower limit of quantification is 20 ng ml(-1) pamidronate in 1 ml of human serum.
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Affiliation(s)
- R W Sparidans
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Centre, The Netherlands
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35
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Sparidans RW, den Hartigh J, Ramp-Koopmanschap WM, Langebroek RH, Vermeij P. The determination of pamidronate in pharmaceutical preparations by ion-pair liquid chromatography after derivatization with phenylisothiocyanate. J Pharm Biomed Anal 1997; 16:491-7. [PMID: 9589408 DOI: 10.1016/s0731-7085(97)00090-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [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: 02/07/2023]
Abstract
An analytical method was developed for the determination of pamidronate [(3-amino-1-hydroxypropylidene)bisphosphonate] by ion-pair liquid chromatography. The analyte was derivatized with phenylisothiocyanate into an UV-absorbing derivative. The reaction product was cleaned-up by a double ion-pair extraction and treated with hydrogen peroxide prior to injection. Both, the detection limit and the lower limit of quantification of pamidronate in water were 0.1 microgram ml-1 disodium pamidronate. The intra-day precision was 3% for a 5-microgram ml-1 pamidronate standard solution and the inter-day precision 6% for a 3-microgram ml-1 solution. The method was applied in the quality control of pamidronate injection concentrates and tablets.
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Affiliation(s)
- R W Sparidans
- Department of Clinical Pharmacy and Toxicology, Leiden University Hospital, The Netherlands
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Sparidans RW, den Hartigh J, Beijnen JH, Vermeij P. Determination of pamidronate in urine by ion-pair liquid chromatography after derivatization with 1-naphthylisothiocyanate. J Chromatogr B Biomed Sci Appl 1997; 696:137-44. [PMID: 9300918 DOI: 10.1016/s0378-4347(97)00226-0] [Citation(s) in RCA: 19] [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: 02/05/2023]
Abstract
A sensitive method for the determination of pamidronate disodium [(3-amino-1-hydroxypropylidene)bisphosphonate, APD] in urine has been developed and validated. The procedure involves a triple co-precipitation with calcium phosphate, solid-phase extraction on a quaternary ammonium column, derivatization with 1-naphthylisothiocyanate and ion-pair liquid-liquid extraction. From the two reaction products, naphthylthiocarbamyl-APD is converted into the other, naphthylcarbamyl-APD, by an oxidative desulphuration with hydrogen-peroxide prior to analysis by ion-pair HPLC and fluorescence detection at 285/390 nm. The method has a coefficient of variation of 7% for the intra-assay precision of 99 ng ml-1 APD and 11% for the inter-assay precision. The lower limit of quantification is 3 ng ml-1 APD in 2.5 ml of human urine.
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Affiliation(s)
- R W Sparidans
- Department of Clinical Pharmacy and Toxicology, Leiden University Hospital, The Netherlands
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Kuijpers EA, den Hartigh J, Savelkoul TJ, de Wolff FA. A method for the simultaneous identification and quantitation of five superwarfarin rodenticides in human serum. J Anal Toxicol 1995; 19:557-62. [PMID: 8577178 DOI: 10.1093/jat/19.7.557] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [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: 01/31/2023] Open
Abstract
A high-performance liquid chromatographic method with ultraviolet (UV) and fluorescence detection was developed for the analysis of one indandione and four hydroxycoumarin anticoagulant rodenticides in human serum. The superwarfarin rodenticides, chlorophacinone, bromadiolone, difenacoum, brodifacoum, and difethialone, can be identified and quantitated simultaneously with this method. After adding a buffer (pH 5.5), the anticoagulants were extracted from serum with chloroform-acetone. The organic phase was separated and evaporated to dryness, and the residue was subjected to chromatographic analysis. The anticoagulants were separated by reversed-phase chromatography and detected by UV absorption at 285 nm and by fluorescence at an excitation wavelength of 265 nm and an emission wavelength of 400 nm. Extraction efficiencies from 55 to 131% were obtained. The within-run precision ranged from 2.0 to 7.1% for UV detection and from 0.0 to 4.8% for fluorescence detection. Between-run precision ranged from 1.3 to 16.0% for UV detection and from 1.8 to 9.0% for fluorescence detection. The anticoagulants can be quantitated at serum concentrations down to 3-12 ng/mL for fluorescence detection and down to 20-75 ng/mL for UV detection. No interferences were observed with the related compounds warfarin and vitamin K1.
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Affiliation(s)
- E A Kuijpers
- Department of Clinical Chemistry, Pharmacy and Toxicology, Leiden University Hospital, The Netherlands
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38
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Sparidans RW, den Hartigh J, Vermeij P. High-performance ion-exchange chromatography with in-line complexation of bisphosphonates and their quality control in pharmaceutical preparations. J Pharm Biomed Anal 1995; 13:1545-50. [PMID: 8788141 DOI: 10.1016/0731-7085(95)01572-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [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: 02/02/2023]
Abstract
An ion-exchange chromatographic method using an anion-exchange column was developed for the analysis of a number of bisphosphonates. The bisphosphonates were in-line complexed by copper(II) ions and added to the acidic eluent, to yield an UV-absorbing complex. Chromatographic parameters were studied for eight different bisphosphonates, particularly amino-1-hydroxyalkyl-1,1-bisphosphonates; special attention was paid to the relationship between retention and complex formation. The method was applied to the quality control of pamidronate injection concentrate and olpadronate tablets. The lower detection limit was 8 ng of disodium pamidronate, and the inter-assay precision was 1.0% for both pamidronate and olpadronate standard solutions and 1.8% for a 3 mg ml-1 disodium pamidronate injection concentrate. The method was compared with a previously described ion-exchange chromatographic method with conductivity detection, without copper(II) ions in the eluent.
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Affiliation(s)
- R W Sparidans
- Department of Clinical Pharmacy and Toxicology, Leiden University Hospital, Netherlands
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39
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Cheung D, van der Veen H, den Hartigh J, Dijkman JH, Sterk PJ. Effects of inhaled substance P on airway responsiveness to methacholine in asthmatic subjects in vivo. J Appl Physiol (1985) 1994; 77:1325-32. [PMID: 7530706 DOI: 10.1152/jappl.1994.77.3.1325] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.0] [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: 01/25/2023] Open
Abstract
We tested the hypothesis that the inhaled tachykinin substance P (SP) can induce hyperresponsiveness to methacholine in asthmatic subjects in vivo. Nine atopic nonsmoking asthmatic males with normal forced expiratory volume in 1 s (FEV1; > 80% predicted) and increased methacholine sensitivity [provocative concn causing 20% fall in FEV1 (PC20) < 8 mg/ml] participated in a two-period placebo-controlled crossover study. Dose-response curves to SP (0.25-8 mg/ml) and placebo were recorded on 2 randomized days at least 1 wk apart, and methacholine tests were done 24 h before and 2 and 24 h after these challenges. The responses were measured by FEV1 (%fall from baseline). The position of the methacholine dose-response curves was expressed by the PC20 FEV1 and by the maximal response by the plateau level (MFEV1). SP caused a dose-dependent fall in FEV1 (P < 0.001). There was a slight increase in the PC20 FEV1 at 2 and 24 h, which was not significantly different between placebo and SP. Similarly, there was a reduction in MFEV1 at 2 h after both pretreatments. However, at 24 h after SP inhalation, MFEV1 increased compared with placebo. These changes in MFEV1 were significantly different between SP and placebo by 5.2 +/- 2.2% fall (SE) (P < 0.05). We conclude that 1) a bronchoconstrictive dose of SP, compared with placebo, enhances maximal airway narrowing to methacholine in asthma 24 h after inhalation and 2) tolerance develops to high doses of inhaled methacholine. These findings are suggestive of a role of SP in causing excessive airway narrowing in asthma by inflammatory mechanisms.
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Affiliation(s)
- D Cheung
- Department of Pulmonology, University Hospital Leiden, The Netherlands
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40
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Twiss IM, de Water R, den Hartigh J, Sparidans R, Ramp-Koopmanschap W, Brill H, Wijdeveld M, Vermeij P. Cytotoxic effects of pamidronate on monolayers of human intestinal epithelial (Caco-2) cells and its epithelial transport. J Pharm Sci 1994; 83:699-703. [PMID: 8071824 DOI: 10.1002/jps.2600830521] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Pamidronate (APD) is a new drug in the treatment of osteolytic bone diseases. Caco-2 cells were used to study the cytotoxic effects of APD on intestinal epithelium and also the transport (mechanism) of APD across the intestinal epithelium. We investigated the cytotoxic effect of APD by combining two spectrophotometric assays [neutral red (NR) uptake and lactate dehydrogenase (LDH) release] with a morphological assay (electron microscopy). The amount of APD transported across the Caco-2 monolayer was measured by HPLC. The permeability of the monolayer was studied by determining the transepithelial electrical resistance (TEER). The results show that after exposing the Caco-2 cells to increasing concentrations of APD [dose range calculated on the basis of relevance to the oral dose administered to patients] the NR uptake decreased while LDH loss increased, which is indicative of a cytotoxic effect of APD. Ultrastructural alterations, including a widening in intercellular spaces and, at higher doses, complete cell death, were observed. The transport percentage of nontoxic doses of APD was low, while the TEER decreased with increasing doses of APD. In conclusion, APD is cytotoxic for Caco-2 cells. As the transport percentage of nontoxic doses of APD is low and APD reduces the TEER, it is hypothesized that APD is transported paracellularly.
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Affiliation(s)
- I M Twiss
- Department of Clinical Pharmacy, University Hospital Leiden, The Netherlands
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41
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van Steveninck AL, Schoemaker HC, den Hartigh J, Rijnkels J, Pieters MS, Breimer DD, Cohen AF. Effects of intravenous temazepam. I. Saccadic eye movements and electroencephalogram after fast and slow infusion to pseudo steady state. Clin Pharmacol Ther 1994; 55:535-45. [PMID: 8181198 DOI: 10.1038/clpt.1994.67] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [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: 01/29/2023]
Abstract
OBJECTIVE To study the pharmacodynamic effects of intravenous temazepam after different infusion rates to pseudo steady-state concentrations. METHODS This was a randomized, double-blind, placebo-controlled crossover study in an academic department of clinical pharmacology. Subjects were nine healthy volunteers. A computerized infusion pump was used to obtain target plasma concentrations of temazepam after 30 or 120 minutes and to maintain these levels for 2 hours. A vehicle infusion, similar to the 30-minute (fast) infusion was used as a placebo control. Infusion schedules were based on data obtained from individual subjects after infusion of 0.4 mg/kg temazepam in 30 minutes. Target plasma concentrations were chosen to induce subhypnotic effects and averaged (+/- SD) 597 +/- 123 ng/ml. Venous plasma concentrations of temazepam were measured by HPLC. Free fractions of temazepam were assessed at the start of the pseudo steady-state concentration intervals. Electroencephalogram alpha and beta amplitudes, saccadic peak velocity, and saccadic latency were used as pharmacodynamic parameters. RESULTS The rate of change of plasma concentrations averaged 21 +/- 4 ng/ml.min-1 during fast infusion and 5 +/- 1 ng/ml.min-1 during slow infusion of temazepam. Average pseudo steady-state concentrations were 639 +/- 132 ng/ml after fast infusion and 629 +/- 133 ng/ml after slow infusion. At the onset of pseudo steady-state concentration intervals the average free fractions of temazepam were 44% (95% confidence interval, 19% to 61%) lower for slow than for fast infusions. Compared with the slow infusion, electroencephalogram beta amplitudes were significantly larger during the first 30 minutes of pseudo steady-state concentration after fast infusion of temazepam. No significant differences were found for the other parameters. There was a slight decline of temazepam effects during the pseudo steady-state concentration intervals for all parameters after the fast infusion and for saccadic peak velocity and saccadic latency after the slow infusion. CONCLUSIONS The pharmacodynamic effects of intravenous temazepam may depend partly on the rate of administration. Differences in pharmacodynamic effects after fast and slow infusions could be caused by changes in protein binding over time.
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Affiliation(s)
- A L van Steveninck
- Center for Human Drug Research, University Hospital Leiden, The Netherlands
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42
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van Steveninck AL, Schoemaker HC, den Hartigh J, Pieters MS, Breimer DD, Cohen AF. Effects of intravenous temazepam. II. A study of the long-term reproducibility of pharmacokinetics, pharmacodynamics, and concentration-effect parameters. Clin Pharmacol Ther 1994; 55:546-55. [PMID: 8181199 DOI: 10.1038/clpt.1994.68] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [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: 01/29/2023]
Abstract
OBJECTIVE To evaluate the long-term reproducibility of pharmacokinetic, pharmacodynamic, and concentration-effect parameters after intravenous administration of temazepam. METHODS Nine healthy volunteers were studied. Temazepam, 0.4 mg/kg, was infused intravenously for 30 minutes on two occasions 6 months apart. Venous plasma concentrations of temazepam were measured by HPLC in samples obtained between 0 and 24 hours. Pharmacodynamic effects were evaluated up to 8 hours for saccadic peak velocity and electroencephalogram (EEG) beta amplitudes. Subjects' state and trait anxiety were assessed by use of the Spielberger anxiety inventory. RESULTS Significant correlations between occasions were found for area under the plasma concentration-time curve (AUC) values (r = 0.91; p < 0.01) but not for maximum concentration and half-life. Significant correlations were also found for area under the effect-time curve (AUEC) values of peak velocity (r = 0.88; p < 0.01) but not for peak velocity (r = 0.48; p > 0.05). Significant differences between the slopes of concentration effect plots on different occasions were observed in two subjects for EEG beta and in three subjects for peak velocity, with one subject showing a similar change for both parameters. Trait anxiety scores were higher on the first occasion (33 +/- 7) than on the second occasion (29 +/- 7; p < 0.01). A negative correlation was found between trait anxiety scores and the slopes of concentration-effect plots for peak velocity (r = -0.63; p < 0.01). CONCLUSIONS For AUC and AUEC values the results indicate a reasonable long-term reproducibility of differences between subjects in the pharmacokinetics and pharmacodynamics of temazepam. However, there were limitations to the predictive value of derived concentration-effect parameters.
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Affiliation(s)
- A L van Steveninck
- Center for Human Drug Research, Leiden University Hospital, The Netherlands
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43
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Cheung D, Timmers MC, Zwinderman AH, den Hartigh J, Dijkman JH, Sterk PJ. Neutral endopeptidase activity and airway hyperresponsiveness to neurokinin A in asthmatic subjects in vivo. Am Rev Respir Dis 1993; 148:1467-73. [PMID: 8256886 DOI: 10.1164/ajrccm/148.6_pt_1.1467] [Citation(s) in RCA: 59] [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] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In a previous study we have shown that inhibition of the endogenous neuropeptide-degrading enzyme, neutral endopeptidase (NEP), potentiates airway narrowing to neurokinin A (NKA) in normal humans in vivo. In the present study, we tested the hypothesis that hyperresponsiveness to NKA in asthma is caused by a reduction in endogenous NEP activity. To that end, we used the NEP inhibitor, thiorphan, or placebo as inhaled pretreatment to NKA challenge in eight atopic asthmatic men, who were controlled by on-demand usage of beta 2-agonists alone. The dose of thiorphan pretreatment was obtained from pilot experiments in which 0.5 ml of a 2.5-mg/ml concentration appeared to be the maximally effective nebulized dose. Dose-response curves to inhaled NKA (1 to 125 micrograms/ml, 0.5 ml/dose) were recorded on 2 randomized days 1 wk apart, in a cross-over study. To detect any effects of thiorphan on bronchoconstriction per se, we also investigated the effect of thiorphan or placebo on the dose-response curve to inhaled methacholine in a separate set of experiments. The response was measured by FEV1 and by partial expiratory flow-volume curves (V40p). The position of the dose-response curves was expressed as the concentration causing a 20% fall in FEV1 (PC20FEV1) or a 40% fall in V40p (PC40V40p). Baseline FEV1 and V40p were not affected by either pretreatment (p > 0.06). PC20FEV1 and PC40V40p to NKA were significantly lower after thiorphan pretreatment as compared with placebo (mean difference +/- SEM: 2.3 +/- 0.6 and 1.6 +/- 0.5 doubling dose, respectively; p < 0.015).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- D Cheung
- Department of Pulmonology, University Hospital Leiden, The Netherlands
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44
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den Hartigh J, Hilders CG, Schoemaker RC, Hulshof JH, Cohen AF, Vermeij P. Tinnitus suppression by intravenous lidocaine in relation to its plasma concentration. Clin Pharmacol Ther 1993; 54:415-20. [PMID: 8222484 DOI: 10.1038/clpt.1993.168] [Citation(s) in RCA: 26] [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: 01/29/2023]
Abstract
In a double-blind controlled trial in nine patients with tinnitus we measured the lidocaine plasma concentrations during and after intravenous administration of lidocaine or placebo and scored the level of tinnitus on a visual analog scale. No patient showed any effect during the placebo infusion. Administration of lidocaine resulted in total suppression or suppression to a non-annoying level of tinnitus in five patients, slight suppression but still annoying tinnitus in two patients, and worsening tinnitus in one patient. No effect of lidocaine was observed in one patient. Most relief was obtained at plasma concentrations between 1.5 and 2.5 micrograms/ml. In this concentration range a significant (p < 0.05) effect of lidocaine on tinnitus was observed. However, notable side effects were observed at plasma concentrations greater than 2.0 micrograms/ml. The effect persisted until plasma levels of about 0.5 microgram/ml were reached. A large variability in the effects existed because of variations in lidocaine kinetics and because of the presumed psychologic components of tinnitus.
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Affiliation(s)
- J den Hartigh
- Department of Clinical Pharmacy, University Medical Centre, Leiden, The Netherlands
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45
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Boets PM, van Vreeswijk H, Verhaegen A, den Hartigh J, van Best JA. Determination of the molar absorption coefficient of fluorescein sodium. Exp Eye Res 1992; 54:143-4. [PMID: 1541332 DOI: 10.1016/0014-4835(92)90078-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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46
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Vermeij P, Hulshof J, Hilders C, den Hartigh J, Cohen A. Lidocaine in the treatment of tinnitus. Eur J Pharmacol 1990. [DOI: 10.1016/0014-2999(90)92872-g] [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: 11/15/2022]
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47
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den Hartigh J, Brandenburg HC, Vermeij P. Stability of azacitidine in lactated Ringer's injection frozen in polypropylene syringes. Am J Hosp Pharm 1989; 46:2500-5. [PMID: 2481397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The stability of azacitidine diluted in lactated Ringer's injection was studied. Azacitidine was reconstituted with ice-cold lactated Ringer's injection to concentrations of 2.0 and 0.5 mg/mL and stored in polypropylene syringes at -20 degrees C. On days 1, 3, 7, and 14, the solutions were thawed over 30-45 minutes and the azacitidine concentration was determined by high-performance liquid chromatography immediately after thawing and one, three, and six hours later. Other studies were conducted at 37, 20, and 0-4 degrees C to determine decomposition rate constants for azacitidine at both concentrations. Hydrolysis of azacitidine resulted in a biphasic decline when the log of the percentage of drug remaining was plotted against time. No substantial decomposition occurred during storage at -20 degrees C. In thawed samples, azacitidine concentrations decreased to 90% of the initial concentrations within three hours after reaching room temperature; similar decreases in concentration were seen in nonfrozen samples stored at room temperature. The results of these studies indicate that azacitidine solutions in lactated Ringer's injection can be stored in polypropylene syringes at -20 degrees C for two weeks without decomposition. The thawed solutions should be used within three hours.
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Affiliation(s)
- J den Hartigh
- Department of Clinical Pharmacy and Toxicology, University Hospital, Leiden, the Netherlands
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Verweij J, den Hartigh J, Stuurman M, de Vries J, Pinedo HM. Relationship between clinical parameters and pharmacokinetics of mitomycin C. J Cancer Res Clin Oncol 1987; 113:91-4. [PMID: 3102501 DOI: 10.1007/bf00389973] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Although the number of reports on mitomycin C (MMC) pharmacokinetics is increasing, data on possible relations between clinical parameters and pharmacokinetics are usually lacking. The present report concerns the results of a detailed study on this subject in 35 patients receiving MMC, either as a single agent or as a part of combination chemotherapy. MMC concentrations were determined by HPLC. T1/2 beta varied from 23 to 78 min, VD from 11 to 48 l/m2, Cl tot from 12 to 42 l/h per m2, and AUC from 138 to 1221 micrograms/h per l, confirming previously reported data. Infusion time, cholestasis, and urinary pH did not influence the pharmacokinetic data. There were no relations between other clinical data and pharmacokinetics, nor between AUC and bone marrow toxicity. An interaction between MMC and furosemide could not be excluded, but there was no interaction with other comedication. Consecutive pharmacokinetics in 6 patients showed consistent results. Because renal impairment does not alter MMC pharmacokinetics and renal excretion is not a major route of elimination, it is suggested that renal impairment does not call for dose adjustment.
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Beijnen JH, den Hartigh J, Underberg WJ. Quantitative aspects of the degradation of mitomycin C in alkaline solution. J Pharm Biomed Anal 1985; 3:59-69. [PMID: 16867710 DOI: 10.1016/0731-7085(85)80007-8] [Citation(s) in RCA: 13] [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] [Received: 07/24/1984] [Revised: 10/04/1984] [Indexed: 11/20/2022]
Abstract
The alkaline hydrolysis of mitomycin C has been studied over a wide range of pH/H_(7-15). A stability-indicating high-performance liquid chromatographic (HPLC) method was used to separate the degradation products from the parent drug. The quantitative effects of temperature and buffers on the degradation of mitomycin C in alkali have been determined. A profile of log k(obs) against pH/H_ was constructed after corrections had been made for buffer effects and after extrapolation to 25 degrees C by application of the Arrhenius equation.
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Affiliation(s)
- J H Beijnen
- Department of Analytical Pharmacy, Subfaculty of Pharmacy, State University of Utrecht, Catharijnesingel 60, 3511 GH Utrecht, The Netherlands
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Beijnen JH, den Hartigh J, Underberg WJ. Qualitative aspects of the degradation of mitomycins in alkaline solution. J Pharm Biomed Anal 1985; 3:71-9. [PMID: 16867711 DOI: 10.1016/0731-7085(85)80008-x] [Citation(s) in RCA: 13] [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] [Received: 07/24/1984] [Revised: 10/04/1984] [Indexed: 11/28/2022]
Abstract
The major degradation product in alkaline solution of mitomycin A, mitomycin C and porfiromycin is the corresponding 7-hydroxymitosane. The isolation and the physico-chemical and analytical properties of these compounds and their derivatized analogues are discussed. Data are presented on the degradation of mitomycin C at extremely high pH values.
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Affiliation(s)
- J H Beijnen
- Department of Analytical Pharmacy, Subfaculty of Pharmacy, State University of Utrecht, Catharijnesingel 60, 3511 GH Utrecht, The Netherlands
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