1
|
Bustamante C, Muskus C, Ochoa R. Rational computational approaches to predict novel drug candidates against leishmaniasis. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2022. [DOI: 10.1016/bs.armc.2022.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
2
|
Bustamante C, Ochoa R, Asela C, Muskus C. Repurposing of known drugs for leishmaniasis treatment using bioinformatic predictions, in vitro validations and pharmacokinetic simulations. J Comput Aided Mol Des 2019; 33:845-854. [PMID: 31612362 DOI: 10.1007/s10822-019-00230-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 09/28/2019] [Indexed: 11/26/2022]
Abstract
Leishmaniasis is a neglected tropical disease caused by Leishmania parasites and is associated to more than 1.3 million cases annually. Some of the pharmacological options for treating the disease are pentavalent antimonials, pentamidine, miltefosine, and amphotericin B. However, all are associated with a wide range of adverse effects and contraindications, as well as resistance from the parasite. In the present study, we looked for pharmacological alternatives to treat leishmaniasis, with a focus on drug repurposing. This was done by detecting potential homologs between proteins targeted by approved drugs and proteins of the parasite. The proteins were analyzed using an interaction network, and the drugs were subjected to in vitro evaluations and pharmacokinetics simulations to compare probable plasma concentrations with the effective concentrations detected experimentally. This strategy yielded a list of 33 drugs with potential anti-Leishmania activity, and more than 80 possible protein targets in the parasite. From the drugs tested, two reported high in vitro activity (perphenazine EC50 = 1.2 µg/mL and rifabutin EC50 = 8.5 µg/mL). These results allowed us to propose these drugs as candidates for further in vivo studies and evaluations of the effectiveness on their topical forms.
Collapse
Affiliation(s)
- Christian Bustamante
- Programa de Estudio y Control de Enfermedades Tropicales-PECET, Faculty of Medicine, University of Antioquia, Medellin, Colombia
| | - Rodrigo Ochoa
- Programa de Estudio y Control de Enfermedades Tropicales-PECET, Faculty of Medicine, University of Antioquia, Medellin, Colombia
- Biophysics of Tropical Diseases, Max Planck Tandem Group, University of Antioquia, Medellin, Colombia
| | - Claudia Asela
- Programa de Estudio y Control de Enfermedades Tropicales-PECET, Faculty of Medicine, University of Antioquia, Medellin, Colombia
| | - Carlos Muskus
- Programa de Estudio y Control de Enfermedades Tropicales-PECET, Faculty of Medicine, University of Antioquia, Medellin, Colombia.
| |
Collapse
|
3
|
Critical Review: What Dose of Rifabutin Is Recommended With Antiretroviral Therapy? J Acquir Immune Defic Syndr 2017; 72:138-52. [PMID: 26855245 DOI: 10.1097/qai.0000000000000944] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Since the advent of combination antiretroviral therapy to successfully treat HIV infection, drug-drug interactions (DDIs) have become a significant problem as many antiretrovirals (ARVs) are metabolized in the liver. Antituberculous therapy traditionally includes rifamycins, particularly rifampicin. Rifabutin (RBT) has shown similar efficacy as rifampicin but induces CYP3A4 to a lesser degree and is less likely to have DDIs with ARVs. We identified 14 DDI pharmacokinetic studies on HIV monoinfected and HIV-tuberculosis coinfected individuals, and the remaining studies were healthy volunteer studies. Although RBT may be coadministered with most nonnucleoside reverse transcriptase inhibitors, identifying the optimal dose with ritonavir-boosted or cobicistat-boosted protease inhibitors is challenging because of concern about adverse effects with increased RBT exposure. Limited healthy volunteer studies on other ARV drug classes and RBT suggest that dose modification may be unnecessary. The paucity of data assessing clinical tuberculosis endpoints concurrently with RBT and ARV pharmacokinetics limits evidence-based recommendations on the optimal dose of RBT within available ARV drug classes.
Collapse
|
4
|
Hennig S, Svensson EM, Niebecker R, Fourie PB, Weiner MH, Bonora S, Peloquin CA, Gallicano K, Flexner C, Pym A, Vis P, Olliaro PL, McIlleron H, Karlsson MO. Population pharmacokinetic drug-drug interaction pooled analysis of existing data for rifabutin and HIV PIs. J Antimicrob Chemother 2016; 71:1330-40. [PMID: 26832753 DOI: 10.1093/jac/dkv470] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 12/04/2015] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES Extensive but fragmented data from existing studies were used to describe the drug-drug interaction between rifabutin and HIV PIs and predict doses achieving recommended therapeutic exposure for rifabutin in patients with HIV-associated TB, with concurrently administered PIs. METHODS Individual-level data from 13 published studies were pooled and a population analysis approach was used to develop a pharmacokinetic model for rifabutin, its main active metabolite 25-O-desacetyl rifabutin (des-rifabutin) and drug-drug interaction with PIs in healthy volunteers and patients who had HIV and TB (TB/HIV). RESULTS Key parameters of rifabutin affected by drug-drug interaction in TB/HIV were clearance to routes other than des-rifabutin (reduced by 76%-100%), formation of the metabolite (increased by 224% in patients), volume of distribution (increased by 606%) and distribution to the peripheral compartment (reduced by 47%). For des-rifabutin, clearance was reduced by 35%-76% and volume of distribution increased by 67%-240% in TB/HIV. These changes resulted in overall increased exposure to rifabutin in TB/HIV patients by 210% because of the effects of PIs and 280% with ritonavir-boosted PIs. CONCLUSIONS Given together with non-boosted or ritonavir-boosted PIs, rifabutin at 150 mg once daily results in similar or higher exposure compared with rifabutin at 300 mg once daily without concomitant PIs and may achieve peak concentrations within an acceptable therapeutic range. Although 300 mg of rifabutin every 3 days with boosted PI achieves an average equivalent exposure, intermittent doses of rifamycins are not supported by current guidelines.
Collapse
Affiliation(s)
- Stefanie Hennig
- School of Pharmacy, University of Queensland, Brisbane, Australia Department of Pharmaceutical Bioscience, Uppsala University, Uppsala, Sweden
| | - Elin M Svensson
- Department of Pharmaceutical Bioscience, Uppsala University, Uppsala, Sweden
| | - Ronald Niebecker
- Department of Pharmaceutical Bioscience, Uppsala University, Uppsala, Sweden
| | - P Bernard Fourie
- Department of Medical Microbiology, University of Pretoria, Pretoria, South Africa
| | - Marc H Weiner
- Department of Medicine, University of Texas Health Science Center and Veterans Administration Medical Center, San Antonio, TX, USA
| | - Stefano Bonora
- Unit of Infectious Diseases, Department of Medical Sciences, University of Torino, Torino, Italy
| | - Charles A Peloquin
- College of Pharmacy and Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | | | - Charles Flexner
- Johns Hopkins Adult AIDS Clinical Trials Unit, Division of Clinical Pharmacology, Baltimore, MD, USA
| | - Alex Pym
- Tuberculosis Research Unit, Medical Research Council and KwaZulu-Natal Research Institute for Tuberculosis and HIV (K-RITH), Durban, South Africa
| | - Peter Vis
- Janssen Infectious Diseases BVBA, Beerse, Belgium
| | - Piero L Olliaro
- Special Programme for Research and Training in Tropical Diseases (TDR), World Health Organization (WHO), Geneva, Switzerland
| | - Helen McIlleron
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Mats O Karlsson
- Department of Pharmaceutical Bioscience, Uppsala University, Uppsala, Sweden
| |
Collapse
|
5
|
Effect of SLCO1B1 Polymorphisms on Rifabutin Pharmacokinetics in African HIV-Infected Patients with Tuberculosis. Antimicrob Agents Chemother 2015; 60:617-20. [PMID: 26482301 DOI: 10.1128/aac.01195-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 10/01/2015] [Indexed: 11/20/2022] Open
Abstract
Rifabutin, used to treat HIV-infected tuberculosis, shows highly variable drug exposure, complicating dosing. Effects of SLCO1B1 polymorphisms on rifabutin pharmacokinetics were investigated in 35 African HIV-infected tuberculosis patients after multiple doses. Nonlinear mixed-effects modeling found that influential covariates for the pharmacokinetics were weight, sex, and a 30% increased bioavailability among heterozygous carriers of SLCO1B1 rs1104581 (previously associated with low rifampin concentrations). Larger studies are needed to understand the complex interactions of host genetics in HIV-infected tuberculosis patients. (This study has been registered at ClinicalTrials.gov under registration no. NCT00640887.).
Collapse
|
6
|
Trobec K, Kerec Kos M, von Haehling S, Springer J, Anker SD, Lainscak M. Pharmacokinetics of drugs in cachectic patients: a systematic review. PLoS One 2013; 8:e79603. [PMID: 24282510 PMCID: PMC3835942 DOI: 10.1371/journal.pone.0079603] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 09/25/2013] [Indexed: 12/27/2022] Open
Abstract
Cachexia is a weight-loss process caused by an underlying chronic disease such as cancer, chronic heart failure, chronic obstructive pulmonary disease, or rheumatoid arthritis. It leads to changes in body structure and function that may influence the pharmacokinetics of drugs. Changes in gut function and decreased subcutaneous tissue may influence the absorption of orally and transdermally applied drugs. Altered body composition and plasma protein concentration may affect drug distribution. Changes in the expression and function of metabolic enzymes could influence the metabolism of drugs, and their renal excretion could be affected by possible reduction in kidney function. Because no general guidelines exist for drug dose adjustments in cachectic patients, we conducted a systematic search to identify articles that investigated the pharmacokinetics of drugs in cachectic patients.
Collapse
Affiliation(s)
- Katja Trobec
- Pharmacy Department, University Clinic of Respiratory and Allergic Diseases Golnik, Golnik, Slovenia
| | - Mojca Kerec Kos
- Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Stephan von Haehling
- Applied Cachexia Research, Department of Cardiology, Charité Medical School, Campus Virchow-Klinikum, Berlin, Germany
- Center for Cardiovascular Research, Charité Medical School, Campus Virchow-Klinikum, Berlin, Germany
| | - Jochen Springer
- Applied Cachexia Research, Department of Cardiology, Charité Medical School, Campus Virchow-Klinikum, Berlin, Germany
- Center for Cardiovascular Research, Charité Medical School, Campus Virchow-Klinikum, Berlin, Germany
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Stefan D. Anker
- Center for Clinical and Basic Research, IRCCS San Raffaele, Rome, Italy
| | - Mitja Lainscak
- Applied Cachexia Research, Department of Cardiology, Charité Medical School, Campus Virchow-Klinikum, Berlin, Germany
- Division of Cardiology, University Clinic of Respiratory and Allergic Diseases Golnik, Golnik, Slovenia
- * E-mail:
| |
Collapse
|
7
|
Zhou H. Population-Based Assessments of Clinical Drug-Drug Interactions: Qualitative Indices or Quantitative Measures? J Clin Pharmacol 2013; 46:1268-89. [PMID: 17050792 DOI: 10.1177/0091270006294278] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Population-based assessments of drug-drug interactions have become more common since the introduction and acceptance of the population pharmacokinetic approach. Unlike traditional methods, population-based studies provide clinically relevant results that can be applied directly to a target patient population. Furthermore, population-based studies do not demand the traditional requirements of intensive pharmacokinetic sampling, rigorous inpatient stays, or stringent assessment schedules. As such, the population-based approach can effectively be used to confirm known drug-drug interactions and further characterize anticipated interactions. A prospectively designed analysis can also reveal drug-drug interactions that might otherwise have gone undetected with traditional methods. Ultimately, these results could help to alleviate clinicians' concerns about using widely marketed drugs in combination therapies and also reduce patients' risk of experiencing unacceptable side effects. This article intends to provide a balanced overview of the population-based approach and its merits, drawbacks, and potential utility in the assessment of drug-drug interactions during clinical drug development.
Collapse
Affiliation(s)
- Honghui Zhou
- Pharmacokinetics, Modeling & Simulation, Clinical Pharmacology & Experimental Medicine, Centocor Research & Development, Malvern, PA 19087, USA
| |
Collapse
|
8
|
Burman WJ, Gallicano K, Peloquin C. Comparative pharmacokinetics and pharmacodynamics of the rifamycin antibacterials. Clin Pharmacokinet 2001; 40:327-41. [PMID: 11432536 DOI: 10.2165/00003088-200140050-00002] [Citation(s) in RCA: 244] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The rifamycin antibacterials, rifampicin (rifampin), rifabutin and rifapentine, are uniquely potent in the treatment of patients with tuberculosis and chronic staphylococcal infections. Absorption is variably affected by food; the maximal concentration of rifampicin is decreased by food, whereas rifapentine absorption is increased in the presence of food. The rifamycins are well-known inducers of enzyme systems involved in the metabolism of many drugs, most notably those metabolised by cytochrome P450 (CYP) 3A. The relative potency of the rifamycins as CYP3A inducers is rifampin > rifapentine > rifabutin; rifabutin is also a CYP3A substrate. The antituberculosis activity of rifampicin is decreased by a modest dose reduction from 600 to 450mg. This somewhat surprising finding may be due to the binding of rifampicin to serum proteins, limiting free, active concentrations of the drug. However, increasing the administration interval (after the first 2 to 8 weeks of therapy) has little effect on the sterilising activity of rifampicin, suggesting that relatively brief exposures to a critical concentration of rifampicin are sufficient to kill intermittently metabolising mycobacterial populations. The high protein binding of rifapentine (97%) may explain the suboptimal efficacy of the currently recommended dose of this drug. The toxicity of rifampicin is related to dose and administration interval, with increasing rates of presumed hypersensitivity with higher doses combined with administration frequency of once weekly or less. Rifabutin toxicity is related to dose and concomitant use of CYP3A inhibitors. The rifamycins illustrate the complexity of predicting the pharmacodynamics of treatment of an intracellular pathogen with the capacity for dormancy.
Collapse
Affiliation(s)
- W J Burman
- Department of Public Health, Denver Health and Hospital Authority, University of Colorado Health Sciences Center, USA.
| | | | | |
Collapse
|
9
|
Mouly S, Aymard G, Tillement JP, Caulin C, Bergmann JF, Urien S. Increased oral ganciclovir bioavailability in HIV-infected patients with chronic diarrhoea and wasting syndrome--a population pharmacokinetic study. Br J Clin Pharmacol 2001; 51:557-65. [PMID: 11422015 PMCID: PMC2014490 DOI: 10.1046/j.0306-5251.2001.01389.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AIMS Despite a lack of data, the antiviral agent ganciclovir is not indicated in AIDS patients with diarrhoea because of its presumed poor oral bioavailability. To assess the effect of diarrhoea on ganciclovir intestinal absorption, we conducted a pharmacokinetic study in 42 HIV-infected patients categorized into three groups: A, HIV stage A and B (n = 15); B, AIDS stage C (n = 13); C, AIDS with chronic diarrhoea and wasting syndrome (n = 14). METHODS Each patient was evaluated for nutritional (body mass index, albumin, transferrin serum levels), inflammatory (haptoglobin, orosomucoid), immunological (CD4 count, plasma viral load) and intestinal (D-xylose test, faecal fat and nitrogen output, intestinal permeability) status. Ganciclovir (1 g) was administered orally to fasted patients. Six blood samples were collected over 24 h. Serum was analysed for ganciclovir by h.p.l.c. Population pharmacokinetic analysis was performed using a nonlinear mixed effects modelling program, MP2. RESULTS Mean intestinal permeability (lactulose/mannitol urinary ratio) was increased in group C (0.2) compared with group A (0.05) and B (0.1) patients. Drug concentration-time profiles were best described by a two-compartment model. Apparent oral clearance (CL/F) and central volume of distribution (V1/F) were influenced by clinical status (group). For groups A and B combined, final parameter estimates of CL/F and V1/F were 256 +/- 98 l h(-1) and 1320 +/- 470 l, respectively. Final parameter estimates for group C were 118 +/- 108 l h(-1) and 652 +/- 573 l for CL/F and V1/F, respectively. The 95% confidence intervals on differences between A and B combined and C were statistically significant ([ + 70, + 206] for CL/F, and [+ 314, + 1022] for V1/F). Compared with groups A and B, ganciclovir CL/F was significantly decreased in group C patients. CONCLUSIONS AIDS patients with diarrhoea and severe disease may benefit from ganciclovir therapy, but a dose adjustment may be required according to their digestive and immunological status.
Collapse
Affiliation(s)
- S Mouly
- Department of Internal Medicine, Lariboisiere Hospital, 75475 Paris Cedex 10, France.
| | | | | | | | | | | |
Collapse
|
10
|
José García M, Dolores Santos M, del Mar Fernández de Gatta M, José Otero M, Domínguez-Gil A. Farmacocinética de poblaciones: una aproximación a la optimización del tratamiento con antimicrobianos. Enferm Infecc Microbiol Clin 2001. [DOI: 10.1016/s0213-005x(01)72616-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
11
|
Mouly S, Aymard G, Diquet B, Caulin C, Bergmann JF. Oral ganciclovir systemic exposure is enhanced in HIV-infected patients with diarrhea and weight loss. J Acquir Immune Defic Syndr 2000; 24:344-51. [PMID: 11015151 DOI: 10.1097/00126334-200008010-00008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To determine whether diarrhea and intestinal malabsorption during HIV infection alter oral ganciclovir systemic exposure. METHODS We studied the oral disposition of ganciclovir in 42 HIV-infected patients stratified into three groups: A (n = 15), HIV (stage A and B); B (n = 13), AIDS (stage C); and C (n = 14), AIDS with chronic diarrhea and wasting syndrome (10% or more weight loss). Each patient was evaluated for nutritional (body mass index, serum albumin and transferrin), immunologic (CD4 count, plasma viral load) and intestinal status (D-xylose test, fecal fat and nitrogen excretion, and intestinal permeability). Following an overnight fast, 1 g oral ganciclovir was given to patients. Six blood samples were collected over 24 hours. Serum was analyzed for ganciclovir by high performance liquid chromatography. Drug disposition was characterized using a population pharmacokinetic approach. RESULTS Mean intestinal permeability increased as HIV disease progressed (0. 05, 0.1, and 0.2 for groups A, B, and C, respectively). Average weight-adjusted maximum concentration (Cmax) in group C was twofold more than that in group A and B patients (12.5 versus 6 and 6.4 ng/ml/kg), and average area under the curve (AUC0-infinity) was threefold greater in group C patients (193 versus 59 and 65 ng. hour/ml/kg in groups A and B, respectively). Mean oral clearance was threefold lower in group C (96 versus 258 and 212 L/hour in groups A and B, respectively). CONCLUSION Because systemic exposure of oral ganciclovir is enhanced in AIDS patients with diarrhea and wasting syndrome, oral ganciclovir therapy may benefit these patients.
Collapse
Affiliation(s)
- S Mouly
- Department of Internal Medicine, Lariboisiere Hospital; and Laboratory of Pharmacology, La Salpétrière Hospital, Paris, France.
| | | | | | | | | |
Collapse
|
12
|
Oral Ganciclovir Systemic Exposure Is Enhanced in HIV-Infected Patients With Diarrhea and Weight Loss. J Acquir Immune Defic Syndr 2000. [DOI: 10.1097/00042560-200008010-00008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
13
|
Abstract
Clarithromycin is a macrolide antibacterial that differs in chemical structure from erythromycin by the methylation of the hydroxyl group at position 6 on the lactone ring. The pharmacokinetic advantages that clarithromycin has over erythromycin include increased oral bioavailability (52 to 55%), increased plasma concentrations (mean maximum concentrations ranged from 1.01 to 1.52 mg/L and 2.41 to 2.85 mg/L after multiple 250 and 500 mg doses, respectively), and a longer elimination half-life (3.3 to 4.9 hours) to allow twice daily administration. In addition, clarithromycin has extensive diffusion into saliva, sputum, lung tissue, epithelial lining fluid, alveolar macrophages, neutrophils, tonsils, nasal mucosa and middle ear fluid. Clarithromycin is primarily metabolised by cytochrome P450 (CYP) 3A isozymes and has an active metabolite, 14-hydroxyclarithromycin. The reported mean values of total body clearance and renal clearance in adults have ranged from 29.2 to 58.1 L/h and 6.7 to 12.8 L/h, respectively. In patients with severe renal impairment, increased plasma concentrations and a prolonged elimination half-life for clarithromycin and its metabolite have been reported. A dosage adjustment for clarithromycin should be considered in patients with a creatinine clearance < 1.8 L/h. The recommended goal for dosage regimens of clarithromycin is to ensure that the time that unbound drug concentrations in the blood remains above the minimum inhibitory concentration is at least 40 to 60% of the dosage interval. However, the concentrations and in vitro activity of 14-hydroxyclarithromycin must be considered for pathogens such as Haemophilus influenzae. In addition, clarithromycin achieves significantly higher drug concentrations in the epithelial lining fluid and alveolar macrophages, the potential sites of extracellular and intracellular respiratory tract pathogens, respectively. Further studies are needed to determine the importance of these concentrations of clarithromycin at the site of infection. Clarithromycin can increase the steady-state concentrations of drugs that are primarily depend upon CYP3A metabolism (e.g., astemidole, cisapride, pimozide, midazolam and triazolam). This can be clinically important for drugs that have a narrow therapeutic index, such as carbamazepine, cyclosporin, digoxin, theophylline and warfarin. Potent inhibitors of CYP3A (e.g., omeprazole and ritonavir) may also alter the metabolism of clarithromycin and its metabolites. Rifampicin (rifampin) and rifabutin are potent enzyme inducers and several small studies have suggested that these agents may significantly decrease serum clarithromycin concentrations. Overall, the pharmacokinetic and pharmacodynamic studies suggest that fewer serious drug interactions occur with clarithromycin compared with older macrolides such as erythromycin and troleandomycin.
Collapse
Affiliation(s)
- K A Rodvold
- College of Pharmacy, University of Illinois at Chicago, USA.
| |
Collapse
|
14
|
Gatti G, Di Biagio A, Casazza R, De Pascalis C, Bassetti M, Cruciani M, Vella S, Bassetti D. The relationship between ritonavir plasma levels and side-effects: implications for therapeutic drug monitoring. AIDS 1999; 13:2083-9. [PMID: 10546861 DOI: 10.1097/00002030-199910220-00011] [Citation(s) in RCA: 145] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To assess whether the neurological or gastrointestinal adverse effects of ritonavir correlate with parameters of ritonavir systemic exposure. METHODS Peak (Cmax) and trough (Cmin) ritonavir plasma levels were compared in 11 patients experiencing side-effects (group A) versus 10 patients without side-effects (group B). Ritonavir was administered with the following escalation dosing scheme: 300, 400, 500 mg twice a day for 3, 4, and 5 days, respectively, then the full dose of 600 mg twice a day. Blood sampling was done in group A within 24 h of the occurrence of side-effects and in group B after at least 3 days of the full dosage regimen. RESULTS Both Cmax and Cmax were significantly higher (Mann-Whitney U test) in patients with side-effects. Cmax was [median (interquartile range)] 26.7 (22.7-33.3) mg/l versus 16.2 (13.4-17.0) mg/l (P = 0.001) and Cmin was 12.6 (9.1-13.9) versus 7.5 (4.9-8.6) mg/l (P = 0.002). CONCLUSION Patients with higher ritonavir concentrations are at a higher risk of experiencing neurological or gastrointestinal side-effects. Individualization of the dosage regimen, e.g. a downward titration of the ritonavir dose in patients with side-effects, guided by plasma level monitoring, may result in a substantial increase in the percentage of patients tolerating ritonavir without increasing the risk of treatment failure as a result of suboptimal systemic exposure.
Collapse
Affiliation(s)
- G Gatti
- Department of Infectious Diseases, University of Genoa, Italy.
| | | | | | | | | | | | | | | |
Collapse
|