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Wang Y, Bahar MA, Jansen AME, Kocks JWH, Alffenaar JWC, Hak E, Wilffert B, Borgsteede SD. Improving antibacterial prescribing safety in the management of COPD exacerbations: systematic review of observational and clinical studies on potential drug interactions associated with frequently prescribed antibacterials among COPD patients. J Antimicrob Chemother 2020; 74:2848-2864. [PMID: 31127283 PMCID: PMC6814093 DOI: 10.1093/jac/dkz221] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 04/13/2019] [Accepted: 04/26/2019] [Indexed: 02/07/2023] Open
Abstract
Background Guidelines advise the use of antibacterials (ABs) in the management of COPD exacerbations. COPD patients often have multiple comorbidities, such as diabetes mellitus and cardiac diseases, leading to polypharmacy. Consequently, drug–drug interactions (DDIs) may frequently occur, and may cause serious adverse events and treatment failure. Objectives (i) To review DDIs related to frequently prescribed ABs among COPD patients from observational and clinical studies. (ii) To improve AB prescribing safety in clinical practice by structuring DDIs according to comorbidities of COPD. Methods We conducted a systematic review by searching PubMed and Embase up to 8 February 2018 for clinical trials, cohort and case–control studies reporting DDIs of ABs used for COPD. Study design, subjects, sample size, pharmacological mechanism of DDI and effect of interaction were extracted. We evaluated levels of DDIs and quality of evidence according to established criteria and structured the data by possible comorbidities. Results In all, 318 articles were eligible for review, describing a wide range of drugs used for comorbidities and their potential DDIs with ABs. DDIs between ABs and co-administered drugs could be subdivided into: (i) co-administered drugs altering the pharmacokinetics of ABs; and (ii) ABs interfering with the pharmacokinetics of co-administered drugs. The DDIs could lead to therapeutic failures or toxicities. Conclusions DDIs related to ABs with clinical significance may involve a wide range of indicated drugs to treat comorbidities in COPD. The evidence presented can support (computer-supported) decision-making by health practitioners when prescribing ABs during COPD exacerbations in the case of co-medication.
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Affiliation(s)
- Yuanyuan Wang
- Department of PharmacoTherapy, -Epidemiology & -Economics, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, The Netherlands
| | - Muh Akbar Bahar
- Department of PharmacoTherapy, -Epidemiology & -Economics, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, The Netherlands.,Faculty of Pharmacy, Hasanuddin University, Makassar, Indonesia
| | - Anouk M E Jansen
- Department of PharmacoTherapy, -Epidemiology & -Economics, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, The Netherlands
| | - Janwillem W H Kocks
- Department of General Practice and Elderly Care Medicine, Groningen Research Institute for Asthma and COPD, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Jan-Willem C Alffenaar
- Department of Clinical Pharmacy & Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.,Faculty of Medicine and Health, School of Pharmacy and Westmead Hospital, University of Sydney, Sydney, Australia
| | - Eelko Hak
- Department of PharmacoTherapy, -Epidemiology & -Economics, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, The Netherlands
| | - Bob Wilffert
- Department of PharmacoTherapy, -Epidemiology & -Economics, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, The Netherlands.,Department of Clinical Pharmacy & Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Sander D Borgsteede
- Department of Clinical Decision Support, Health Base Foundation, Houten, The Netherlands.,Department of Hospital Pharmacy, Erasmus University Medical Center, Rotterdam, The Netherlands
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Jeong R, Quinn RR, Lentine KL, Lloyd A, Ravani P, Hemmelgarn B, Braam B, Garg AX, Wen K, Wong-Chan A, Gourishankar S, Lam NN. Outcomes Following Macrolide Use in Kidney Transplant Recipients. Can J Kidney Health Dis 2019; 6:2054358119830706. [PMID: 30815270 PMCID: PMC6385328 DOI: 10.1177/2054358119830706] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 01/15/2019] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Calcineurin inhibitors (CNI; cyclosporine, tacrolimus) are critical for kidney transplant immunosuppression, but have multiple potential drug interactions, such as with macrolide antibiotics. Macrolide antibiotics (clarithromycin, erythromycin, and azithromycin) are often used to treat atypical infections. Clarithromycin and erythromycin inhibit CNI metabolism and increase the risk of CNI nephrotoxicity, while azithromycin does not. OBJECTIVE To determine the frequency of CNI-macrolide co-prescriptions, the proportion who receive post-prescription monitoring, and the risk of adverse drug events in kidney transplant recipients. DESIGN Retrospective cohort study. SETTING We used linked health care databases in Alberta, Canada. PATIENTS We included 293 adult kidney transplant recipients from 2008-2015 who were co-prescribed a CNI and macrolide. MEASUREMENTS The primary outcome was a composite of all-cause hospitalization, acute kidney injury (creatinine increase ≥0.3 mg/dL or 1.5 times baseline), or death within 30 days of the macrolide prescription. METHODS We identified CNI-macrolide co-prescriptions and compared outcomes in those who received clarithromycin/erythromycin versus azithromycin. We used a linear mixed-effects model to examine the mean change in serum creatinine and estimated glomerular filtration rate (eGFR). RESULTS Of the 293 recipients who were co-prescribed a CNI and a macrolide, 38% (n = 112) were prescribed clarithromycin/erythromycin while 62% (n = 181) were prescribed azithromycin. Compared with azithromycin users, clarithromycin/erythromycin users were less likely to have outpatient serum creatinine monitoring post-prescription (56% vs 69%, P = .03). There was no significant difference in the primary outcome between the 2 groups (17% vs 11%, P = .11); however, the risk of all-cause hospitalization was higher in the clarithromycin/erythromycin group (10% vs 3%, P = .02). The mean decrement in eGFR was significantly greater in the clarithromycin/erythromycin versus azithromycin group (-5.4 vs -1.9 mL/min/1.73 m2, P < .05). LIMITATIONS We did not have CNI levels to correlate with the timing of CNI-macrolide co-prescriptions. We also did not have information regarding the indications for macrolide prescriptions. CONCLUSION Clarithromycin and erythromycin were frequently co-prescribed in kidney transplant recipients on CNIs despite known drug interactions. Clarithromycin/erythromycin use was associated with a higher risk of hospitalization compared with azithromycin users. Safer prescribing practices in kidney transplant recipients are warranted.
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Affiliation(s)
- Rachel Jeong
- Department of Medicine, Division of Nephrology, University of Alberta, Edmonton, AB, Canada
| | - Robert R. Quinn
- Departments of Community Health Sciences and Medicine, University of Calgary, Calgary, AB, Canada
| | - Krista L. Lentine
- Center for Abdominal Transplantation, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Anita Lloyd
- Department of Medicine, Division of Nephrology, University of Alberta, Edmonton, AB, Canada
| | - Pietro Ravani
- Department of Medicine, Division of Nephrology, University of Calgary, Calgary, AB, Canada
| | - Brenda Hemmelgarn
- Department of Medicine, Division of Nephrology, University of Calgary, Calgary, AB, Canada
| | - Branko Braam
- Department of Medicine, Division of Nephrology, University of Alberta, Edmonton, AB, Canada
| | - Amit X. Garg
- Department of Medicine, Division of Nephrology, Western University, London, ON, Canada
| | - Kevin Wen
- Department of Medicine, Division of Nephrology, University of Alberta, Edmonton, AB, Canada
| | - Anita Wong-Chan
- Department of Medicine, Division of Nephrology, University of Alberta, Edmonton, AB, Canada
| | - Sita Gourishankar
- Department of Medicine, Division of Nephrology, University of Alberta, Edmonton, AB, Canada
| | - Ngan N. Lam
- Department of Medicine, Division of Nephrology, University of Alberta, Edmonton, AB, Canada
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3
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Tod M, Goutelle S, Bleyzac N, Bourguignon L. A Generic Model for Quantitative Prediction of Interactions Mediated by Efflux Transporters and Cytochromes: Application to P-Glycoprotein and Cytochrome 3A4. Clin Pharmacokinet 2018; 58:503-523. [DOI: 10.1007/s40262-018-0711-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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4
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Xie Y, Dilibero D, Chang DH. Review of Major Drug-Drug Interactions in Thoracic Transplantation. CURRENT TRANSPLANTATION REPORTS 2018. [DOI: 10.1007/s40472-018-0200-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Abstract
Drug-drug interactions (DDIs) occur commonly and may lead to severe adverse drug reactions if not handled appropriately. Considerable information to support clinical decision making regarding potential DDIs is available in the literature and through various systems providing electronic decision support for healthcare providers. The challenge for the prescribing physician lies in sorting out the evidence and identifying those drugs for which potential interactions are likely to become clinically manifest. P-glycoprotein (P-gp) is a drug transporting protein that is found in the plasma membranes in cells of barrier and elimination organs, and plays a role in drug absorption and excretion. Increasingly, P-gp has been acknowledged as an important player in potential DDIs and a growing body of information on the role of this transporter in DDIs has become available from research and from the drug approval process. This has led to a clear need for a comprehensive review of P-gp-mediated DDIs with a focus on highlighting the drugs that are likely to lead to clinically relevant DDIs. The objective of this review is to provide information for identifying and interpreting evidence of P-gp-mediated DDIs and to suggest a classification for individual drugs based on both in vitro and in vivo evidence (substrates, inhibitors and inducers). Further, various ways of handling potential DDIs in clinical practice are described and exemplified in relation to drugs interfering with P-gp.
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Vanhove T, Annaert P, Kuypers DRJ. Clinical determinants of calcineurin inhibitor disposition: a mechanistic review. Drug Metab Rev 2016; 48:88-112. [DOI: 10.3109/03602532.2016.1151037] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Gavhane YN, Yadav AV. Loss of orally administered drugs in GI tract. Saudi Pharm J 2012; 20:331-44. [PMID: 23960808 PMCID: PMC3744959 DOI: 10.1016/j.jsps.2012.03.005] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2012] [Accepted: 03/30/2012] [Indexed: 12/11/2022] Open
Abstract
The aim of this review is to provide a broad perspective on intestinal absorption and the impact of intestinal first-pass metabolism on both clearance and drug-drug interaction prediction along with its historical perspectives. The review also considers abilities to bridge the gap between the increasing amount of intestinal in vitro data and the importance of intestinal first-pass metabolism in vivo. The significance of efflux transporters on the intestinal absorption is also discussed.
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Affiliation(s)
| | - Adhikrao Vyankatrao Yadav
- Gaurishankar Education Society’s Institute of Pharmaceutical Education and Research, Limb, Satara (MS), India
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8
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9
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Bolhuis MS, Panday PN, Pranger AD, Kosterink JGW, Alffenaar JWC. Pharmacokinetic drug interactions of antimicrobial drugs: a systematic review on oxazolidinones, rifamycines, macrolides, fluoroquinolones, and Beta-lactams. Pharmaceutics 2011; 3:865-913. [PMID: 24309312 PMCID: PMC3857062 DOI: 10.3390/pharmaceutics3040865] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Revised: 10/26/2011] [Accepted: 11/09/2011] [Indexed: 12/17/2022] Open
Abstract
Like any other drug, antimicrobial drugs are prone to pharmacokinetic drug interactions. These drug interactions are a major concern in clinical practice as they may have an effect on efficacy and toxicity. This article provides an overview of all published pharmacokinetic studies on drug interactions of the commonly prescribed antimicrobial drugs oxazolidinones, rifamycines, macrolides, fluoroquinolones, and beta-lactams, focusing on systematic research. We describe drug-food and drug-drug interaction studies in humans, affecting antimicrobial drugs as well as concomitantly administered drugs. Since knowledge about mechanisms is of paramount importance for adequate management of drug interactions, the most plausible underlying mechanism of the drug interaction is provided when available. This overview can be used in daily practice to support the management of pharmacokinetic drug interactions of antimicrobial drugs.
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Affiliation(s)
- Mathieu S Bolhuis
- Department of Hospital and Clinical Pharmacy, University Medical Center Groningen, University of Groningen, PO Box 30.001, 9700 RB Groningen, The Netherlands.
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10
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Stass H, Delesen H, Kubitza D, Mai I, Bauer S, Roots I. Moxifloxacin does not alter ciclosporin pharmacokinetics in transplant patients: a multiple-dose, uncontrolled, single-centre study. Clin Drug Investig 2010; 30:279-87. [PMID: 20384384 DOI: 10.1007/bf03256904] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Moxifloxacin has a broad antibacterial spectrum and rapid bactericidal activity, and is thus a good option for the treatment of bacterial infections in patients who have undergone organ or bone marrow transplantation. Transplant patients also receive immunosuppressant therapy such as ciclosporin. OBJECTIVE The primary objective of this study was to assess the steady-state pharmacokinetics of ciclosporin with and without concomitant treatment with moxifloxacin in transplant recipients. A secondary objective was to determine the safety and tolerability of the combined treatment. METHODS Patients (n = 9) with stable graft function after bone marrow or renal transplantation and who were already receiving ciclosporin therapy were enrolled into the study. The patients were given ciclosporin (Sandimmun Optoral) capsules twice daily (total daily dosage 150-380 mg/day) throughout the study period. Moxifloxacin (Avolox) tablets 400 mg once daily were given on days 2-8 inclusive. The primary outcome measure was the change in ciclosporin pharmacokinetics on coadministration with moxifloxacin. Secondary outcomes were the steady-state pharmacokinetics of moxifloxacin and ciclosporin plus its metabolites in patients receiving moxifloxacin and ciclosporin concomitantly. Moxifloxacin pharmacokinetic parameters in the presence of ciclosporin were compared with previously published pharmacokinetic data for moxifloxacin in healthy individuals. RESULTS No significant changes occurred in the concentration-time curves of ciclosporin and its metabolites following combination therapy with moxifloxacin. The geometric means of whole blood concentrations of ciclosporin and ciclosporin plus its metabolites on day 1 were similar to those on day 8 following combined administration of ciclosporin and moxifloxacin for 7 days. The ratio of combination treatment to monotherapy for ciclosporin was 1.01 (90% CI 0.91, 1.11) for the area under the blood concentration-time curve from time zero to 12 hours at steady state (AUC(12,ss)) and 0.96 (90% CI 0.88, 1.04) for the maximum steady-state blood drug concentration (C(max,ss)). For ciclosporin plus its metabolites the ratio was 1.07 (90% CI 0.99, 1.17) for AUC(12,ss) and 1.03 (90% CI 0.98, 1.09) for C(max,ss). The pharmacokinetic parameters for moxifloxacin were unaffected by the presence of ciclosporin. CONCLUSIONS Concomitant administration of moxifloxacin does not alter the pharmacokinetic parameters of ciclosporin or ciclosporin plus its metabolites in immunosuppressed patients. Therefore, no dose adjustments or additional drug monitoring are required when ciclosporin is coadministered with moxifloxacin.
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Affiliation(s)
- Heino Stass
- Bayer HealthCare AG, Clinical Pharmacology, Wuppertal, Germany.
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11
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Stass H, Delesen H, Kubitza D, Mai I, Bauer S, Roots I. Moxifloxacin does not Alter Ciclosporin Pharmacokinetics in Transplant Patients. Clin Drug Investig 2010. [DOI: 10.2165/11534310-000000000-00000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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12
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Galetin A, Gertz M, Houston JB. Potential role of intestinal first-pass metabolism in the prediction of drug-drug interactions. Expert Opin Drug Metab Toxicol 2008; 4:909-22. [PMID: 18624679 DOI: 10.1517/17425255.4.7.909] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND The contribution of intestine to the magnitude of drug-drug interactions (DDI) may be significant, considering high levels of inhibitors in the gut lumen achieved during absorption and the abundance of metabolic enzymes in the mature enterocytes. Intestinal inhibition is incorporated in the DDI prediction models as the ratio of the intestinal wall availability in the presence and absence of the inhibitor (F(G)(') and F(G), respectively). OBJECTIVE This review will focus on the ability of the current approaches to estimate the extent of intestinal DDI accurately, addressing predominantly the most abundant intestinal P450 enzyme, CYP3A4. METHODS Considering the sensitivity of the DDI prediction models to the accuracy of the F(G) estimates, the current study focuses on 3 different in vitro and in vivo approaches to assess this parameter. RESULTS/CONCLUSION The advantages and limitations of each of F(G) methods are outlined. Accurate assessment of this parameter is essential for the prediction of human drug clearance and drug-drug interaction potential.
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Affiliation(s)
- Aleksandra Galetin
- University of Manchester, School of Pharmacy and Pharmaceutical Sciences, Oxford Road, Manchester, M13 9PT, UK.
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Ekbal NJ, Holt DW, MacPhee IAM. Pharmacogenetics of immunosuppressive drugs: prospect of individual therapy for transplant patients. Pharmacogenomics 2008; 9:585-96. [DOI: 10.2217/14622416.9.5.585] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The immunosuppressive drugs used in solid-organ transplantation are potent and toxic agents with narrow therapeutic ranges. Underdosing is associated with immunological rejection of the transplanted organ, whereas overdosing results in infections, malignancy and direct toxicity to a number of organs. Pharmacokinetic heterogeneity makes initial dose determination difficult, as there is a poor correlation between dose and blood concentration. Therapeutic drug monitoring is available but the pharmacokinetic–pharmacodynamic association is imperfect and it does not help in achieving target blood concentrations during the critical early 2–3 days after transplantation. Genetic polymorphisms in drug targets, drug-metabolizing enzymes and drug efflux pumps have been identified as potential targets for developing a pharmacogenetic strategy to individualize initial drug choice and dose. To date, use of the CYP3A5 genotype to predict the appropriate initial dose of tacrolimus is the most promising option for individualization of drug therapy in organ transplantation.
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Affiliation(s)
- Nasirul J Ekbal
- St George’s, University of London, Cellular and Molecular Medicine: Renal Medicine, Cranmer Terrace, London, SW17 0RE, UK
| | - David W Holt
- St George’s, University of London, Cardiac and Vascular Sciences: Analytical Unit, Cranmer Terrace, London, SW17 0RE, UK
| | - Iain AM MacPhee
- St George’s, University of London, Cellular and Molecular Medicine: Renal Medicine, Cranmer Terrace, London, SW17 0RE, UK
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Marchetti S, Mazzanti R, Beijnen JH, Schellens JHM. Concise Review: Clinical Relevance of Drug–Drug and Herb–Drug Interactions Mediated by the ABC Transporter ABCB1 (MDR1, P‐glycoprotein). Oncologist 2007; 12:927-41. [PMID: 17766652 DOI: 10.1634/theoncologist.12-8-927] [Citation(s) in RCA: 179] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The importance of P-glycoprotein (P-gp) in drug-drug interactions is increasingly being identified. P-gp has been reported to affect the pharmacokinetics of numerous structurally and pharmacologically diverse substrate drugs. Furthermore, genetic variability in the multidrug resistance 1 gene influences absorption and tissue distribution of drugs transported. Inhibition or induction of P-gp by coadministered drugs or food as well as herbal constituents may result in pharmacokinetic interactions leading to unexpected toxicities or undertreatment. On the other hand, modulation of P-gp expression and/or activity may be a useful strategy to improve the pharmacological profile of anticancer P-gp substrate drugs. In recent years, the use of complementary and alternative medicine (CAM), like herbs, food, and vitamins, by cancer patients has increased significantly. CAM use substantially increases the risk for interactions with anticancer drugs, especially because of the narrow therapeutic window of these compounds. However, for most CAMs, it is unknown whether they affect metabolizing enzymes and/or drug transporter activity. Clinically relevant interactions are reported between St John's wort or grapefruit juice and anticancer as well as nonanticancer drugs. CAM-drug interactions could explain, at least in part, the large interindividual variation in efficacy and toxicity associated with drug therapy in both cancer and noncancer patients. The study of drug-drug, food-drug, and herb-drug interactions and of genetic factors affecting pharmacokinetics and pharmacodynamics is expected to improve drug safety and will enable individualized drug therapy. Disclosure of potential conflicts of interest is found at the end of this article.
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Affiliation(s)
- Serena Marchetti
- The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
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Ohno Y, Hisaka A, Suzuki H. General Framework for the Quantitative Prediction of CYP3A4-Mediated Oral Drug Interactions Based on the AUC Increase by Coadministration of??Standard Drugs. Clin Pharmacokinet 2007; 46:681-96. [PMID: 17655375 DOI: 10.2165/00003088-200746080-00005] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
BACKGROUND Cytochrome P450 (CYP) 3A4 is the most prevalent metabolising enzyme in the human liver and is also a target for various drug interactions of significant clinical concern. Even though there are numerous reports regarding drug interactions involving CYP3A4, it is far from easy to estimate all potential interactions, since too many drugs are metabolised by CYP3A4. For this reason, a comprehensive framework for the prediction of CYP3A4-mediated drug interactions would be of considerable clinical importance. OBJECTIVE The objective of this study was to provide a robust and practical method for the prediction of drug interactions mediated by CYP3A4 using minimal in vivo information from drug-interaction studies, which are often carried out early in the course of drug development. DATA SOURCES The analysis was based on 113 drug-interaction studies reported in 78 published articles over the period 1983-2006. The articles were used if they contained sufficient information about drug interactions. Information on drug names, doses and the magnitude of the increase in the area under the concentration-time curve (AUC) were collected. METHODS The ratio of the contribution of CYP3A4 to oral clearance (CR(CYP)(3A4)) was calculated for 14 substrates (midazolam, alprazolam, buspirone, cerivastatin, atorvastatin, ciclosporin, felodipine, lovastatin, nifedipine, nisoldipine, simvastatin, triazolam, zolpidem and telithromycin) based on AUC increases observed in interaction studies with itraconazole or ketoconazole. Similarly, the time-averaged apparent inhibition ratio of CYP3A4 (IR(CYP)(3A4)) was calculated for 18 inhibitors (ketoconazole, voriconazole, itraconazole, telithromycin, clarithromycin, saquinavir, nefazodone, erythromycin, diltiazem, fluconazole, verapamil, cimetidine, ranitidine, roxithromycin, fluvoxamine, azithromycin, gatifloxacin and fluoxetine) primarily based on AUC increases observed in drug-interaction studies with midazolam. The increases in the AUC of a substrate associated with coadministration of an inhibitor were estimated using the equation 1/(1 - CR(CYP)(3A4) x IR(CYP)(3A4)), based on pharmacokinetic considerations. RESULTS The proposed method enabled predictions of the AUC increase by interactions with any combination of these substrates and inhibitors (total 251 matches). In order to validate the reliability of the method, the AUC increases in 60 additional studies were analysed. The method successfully predicted AUC increases within 67-150% of the observed increase for 50 studies (83%) and within 50-200% for 57 studies (95%). Midazolam is the most reliable standard substrate for evaluation of the in vivo inhibition of CYP3A4. The present analysis suggests that simvastatin, lovastatin and buspirone can be used as alternatives. To evaluate the in vivo contribution of CYP3A4, ketoconazole or itraconazole is the selective inhibitor of choice. CONCLUSION This method is applicable to (i) prioritize clinical trials for investigating drug interactions during the course of drug development and (ii) predict the clinical significance of unknown drug interactions. If a drug-interaction study is carefully designed using appropriate standard drugs, significant interactions involving CYP3A4 will not be missed. In addition, the extent of CYP3A4-mediated interactions between many other drugs can be predicted using the current method.
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Affiliation(s)
- Yoshiyuki Ohno
- Department of Pharmacy, University of Tokyo Hospital Faculty of Medicine, University of Tokyo, Tokyo, Japan
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17
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Galetin A, Burt H, Gibbons L, Houston JB. PREDICTION OF TIME-DEPENDENT CYP3A4 DRUG-DRUG INTERACTIONS: IMPACT OF ENZYME DEGRADATION, PARALLEL ELIMINATION PATHWAYS, AND INTESTINAL INHIBITION. Drug Metab Dispos 2005; 34:166-75. [PMID: 16221752 DOI: 10.1124/dmd.105.006874] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Time-dependent inhibition of CYP3A4 often results in clinically significant drug-drug interactions. In the current study, 37 in vivo cases of irreversible inhibition were collated, focusing on macrolides (erythromycin, clarithromycin, and azithromycin) and diltiazem as inhibitors. The interactions included 17 different CYP3A substrates showing up to a 7-fold increase in AUC (13.5% of studies were in the range of potent inhibition). A systematic analysis of the impact of CYP3A4 degradation half-life (mean t1/2deg = 3 days, ranging from 1 to 6 days) on the prediction of the extent of interaction for compounds with a differential contribution from CYP3A4 to the overall elimination (defined by fmCYP3A4) was performed. Although the prediction accuracy was very sensitive to the CYP3A4 degradation rate for substrates mainly eliminated by this enzyme fm(CYP3A4 >or= 0.9), minimal effects are observed when CYP3A4 contributes less than 50% to the overall elimination in cases when the parallel elimination pathway is not subject to inhibition. Use of the mean CYP3A4 t1/2deg (3 days), average unbound systemic plasma concentration of the inhibitor, and the corresponding fm(CYP3A4) resulted in 89% of studies predicted within 2-fold of the in vivo value. The impact of the interaction in the gut wall was assessed by assuming maximal intestinal inhibition of CYP3A4. Although a reduced number of false-negative predictions was observed, there was an increased number of overpredictions, and generally, a loss of prediction accuracy was observed. The impact of the possible interplay between CYP3A4 and efflux transporters on the intestinal interaction requires further evaluation.
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Affiliation(s)
- Aleksandra Galetin
- School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
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Mizuno N, Sugiyama Y. Drug transporters: their role and importance in the selection and development of new drugs. Drug Metab Pharmacokinet 2005; 17:93-108. [PMID: 15618657 DOI: 10.2133/dmpk.17.93] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Drug transporters expressed in various tissues play a significant role in drug disposition. By regulating the function of such transporters, it may be possible to eventually develop drugs with ideal pharmacokinetic profiles. In this article, we summarize the significant role played by drug transporters in drug disposition, focusing particularly on their potential use during the drug development process. The ability to manipulate transporter function offers the opportunity of being able to deliver a drug to the target organ, avoiding distribution to other organs (thereby reducing the chance of toxic side-effects), controlling the elimination process, and/or improving oral bioavailability. During drug development, it would be very useful to be able to select a lead compound that may or may not interact with transporters, depending on whether such an interaction is desirable. The use of specific inhibitors of transporters is also an attractive approach to controlling drug disposition, leading to improved efficacy. Currently, optimizing the pharmacokinetic properties of a drug during the early stages of its development is widely accepted as being of great importance. High-throughput screening systems using transporter gene transfected cells or computational (in silico) approaches are efficient tools for assessing transport activity during the early stage of drug development. In addition, drug-drug interactions involving drug transporters and functional genetic polymorphisms of drug transporters are also described. It would also be extremely valuable to be able to quantitatively predict inter-individual pharmacokinetic differences caused by transporter polymorphisms or pharmacokinetic changes caused by drug-drug interactions involving transporters during drug development.
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Affiliation(s)
- Naomi Mizuno
- Pharmacokinetics Laboratory, Mitsubishi Pharma, Co., Chiba, Japan
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Fredericks S, Holt DW, MacPhee IAM. The pharmacogenetics of immunosuppression for organ transplantation: a route to individualization of drug administration. ACTA ACUST UNITED AC 2004; 3:291-301. [PMID: 14575518 DOI: 10.2165/00129785-200303050-00001] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Transplantation has transformed the treatment of patients with organ failure in a number of clinical settings, and immunosuppressive drug therapy is fundamental to its success. However, all the drugs in current use have a narrow therapeutic index. Under-dosing can lead to rejection, while over-dosing increases the risks of infection, malignant disease, and serious drug-specific adverse effects, including diabetes mellitus, nephrotoxicity, hypertension, and hyperlipidemia. Heterogeneity in the pharmacokinetics of these drugs makes initial dose determination difficult, as there is a poor correlation between dose and blood concentration. This results in difficulties in achieving target blood concentrations early after transplantation, which are important for reducing the rate of immunological rejection. This problem is compounded by the observation that neither drug dose nor drug blood concentration accurately predict clinical efficacy or toxicity. The main determinant of heterogeneity in dose requirements is intestinal absorption of the active drug. The oxidative enzymes, cytochrome P450 (CYP) 3A4 and CYP3A5, and the drug efflux pump P-glycoprotein (P-gp) in enterocytes regulate this process. Most substrates for the P-gp pump are also substrates for the CYP3A enzymes. An efficient barrier to xenobiotic absorption is formed by the CYP enzymes and P-gp, and by the two systems working synergistically. Genetic polymorphisms have been reported for the genes associated with the expression of the CYP3A enzymes and P-gp. Genotyping patients for CYP3A genes has the potential to aid the establishment of optimal dosage regimens for transplant patients. Genetic polymorphism of the multiple drug resistance gene-1 (MDR1, also known as ABCB1) [3435C/T] and the CYP3A5 genes (CYP3A5*1, CYP3AP1*1) have the greatest potential to influence the pharmacokinetics of immunosuppressants. Homozygosity of the T allele of the MDR1 3435C/T polymorphism has been associated with reduced enterocyte expression of P-gp resulting in increased drug absorption. The presence of the CYP3A5*1 allele is necessary for the production of a fully catalytic CYP3A5 protein, and also influences the ratio of CYP3A4 : CYP3A5 as well as the overall CYP3A catalytic activity. The CYP3A4 : CYP3A5 ratio may, in turn, influence the pattern of drug metabolites formed. Heterogeneity in the production of active and inactive metabolites has implications for both the pharmacokinetics and pharmacodynamics of these drugs.Gene frequencies and drug dose requirements differ between ethnic groups. Ethnic differences in dose requirements for immunosuppressants have been discussed widely. However, ethnicity is a rather crude marker for genotype. Pharmacogenetic typing offers the possibility of significant improvement in the individualization of immunosuppressive drug prescribing with reduced rates of rejection and toxicity.
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Affiliation(s)
- Salim Fredericks
- Department of Cardiovascular Medicine, Analytical Unit, St George's Hospital Medical School, Cranmer Terrace, London SW17 0RE, UK
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20
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Mizuno N, Niwa T, Yotsumoto Y, Sugiyama Y. Impact of drug transporter studies on drug discovery and development. Pharmacol Rev 2003; 55:425-61. [PMID: 12869659 DOI: 10.1124/pr.55.3.1] [Citation(s) in RCA: 398] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Drug transporters are expressed in many tissues such as the intestine, liver, kidney, and brain, and play key roles in drug absorption, distribution, and excretion. The information on the functional characteristics of drug transporters provides important information to allow improvements in drug delivery or drug design by targeting specific transporter proteins. In this article we summarize the significant role played by drug transporters in drug disposition, focusing particularly on their potential use during the drug discovery and development process. The use of transporter function offers the possibility of delivering a drug to the target organ, avoiding distribution to other organs (thereby reducing the chance of toxic side effects), controlling the elimination process, and/or improving oral bioavailability. It is useful to select a lead compound that may or may not interact with transporters, depending on whether such an interaction is desirable. The expression system of transporters is an efficient tool for screening the activity of individual transport processes. The changes in pharmacokinetics due to genetic polymorphisms and drug-drug interactions involving transporters can often have a direct and adverse effect on the therapeutic safety and efficacy of many important drugs. To obtain detailed information about these interindividual differences, the contribution made by transporters to drug absorption, distribution, and excretion needs to be taken into account throughout the drug discovery and development process.
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Affiliation(s)
- Naomi Mizuno
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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21
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Doherty MM, Charman WN. The mucosa of the small intestine: how clinically relevant as an organ of drug metabolism? Clin Pharmacokinet 2002; 41:235-53. [PMID: 11978143 DOI: 10.2165/00003088-200241040-00001] [Citation(s) in RCA: 156] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The intestinal mucosa is capable of metabolising drugs via phase I and II reactions. Increasingly, as a result of in vitro and in vivo (animal and human) data, the intestinal mucosa is being implicated as a major metabolic organ for some drugs. This has been supported by clinical studies of orally administered drugs (well-known examples include cyclosporin, midazolam, nifedipine and tacrolimus) where intestinal drug metabolism has significantly reduced oral bioavailability. This review discusses the intestinal properties and processes that contribute to drug metabolism. An understanding of the interplay between the processes controlling absorption, metabolism and P-glycoprotein-mediated efflux from the intestinal mucosa into the intestinal lumen facilitates determination of the extent of the intestinal contribution to first-pass metabolism. The clinical relevance of intestinal metabolism, however, depends on the relative importance of the metabolic pathway involved, the therapeutic index of the drug and the inherent inter- and intra-individual variability. This variability can stem from genetic (metabolising enzyme polymorphisms) and/or non-genetic (including concomitant drug and food intake, route of administration) sources. An overwhelming proportion of clinically relevant drug interactions where the intestine has been implicated as a major contributor to first-pass metabolism involve drugs that undergo cytochrome P450 (CYP) 3A4-mediated biotransformation and are substrates for the efflux transporter P-glycoprotein. Much work is yet to be done in characterising the clinical impact of other enzyme systems on drug therapy. In order to achieve this, the first-pass contributions of the intestine and liver must be successfully decoupled.
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Affiliation(s)
- Margaret M Doherty
- Department of Pharmaceutics, Victorian College of Pharmacy, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia.
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22
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Page RL, Ruscin JM, Fish D, Lapointe M. Possible interaction between intravenous azithromycin and oral cyclosporine. Pharmacotherapy 2001; 21:1436-43. [PMID: 11714218 DOI: 10.1592/phco.21.17.1436.34434] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A 42-year-old man who had received a cadaveric kidney transplant 9 years earlier was admitted to the hospital with pneumonia. His oral cyclosporine dosage for the past 2 years was stabilized at 100 mg twice/day; his cyclosporine whole blood trough levels 15 days earlier and on the day he was admitted were both 178 ng/ml. The patient was treated with intravenous ceftriaxone and intravenous azithromycin and continued to receive the same dosage of oral cyclosporine. On hospital day 3, his cyclosporine trough level rose to 400 ng/ml and his dosage was reduced by 50%. Trough levels were 181 ng/ml and 175 ng/ml on hospital days 6 and 9, respectively On hospital day 9, the patient stopped receiving azithromycin. On hospital day 14, his cyclosporine trough level dropped to 76 ng/ml, and his cyclosporine dosage was increased back to 100 mg twice/day. The dosage produced trough levels consistent with those before he had been admitted. The patient was discharged on day 20, and a follow-up cyclosporine trough level determined 3 weeks later was 175 ng/ml. Administration of azithromycin may have caused the increased cyclosporine concentrations in this patient through p-glycoprotein inhibition and/or competition for biliary excretion. Azithromycin's interference may be inferred by the increase in cyclosporine levels after administration of this drug and the decrease in cyclosporine levels after its discontinuation-both consistent with the pharmacokinetic properties of cyclosporine. Ceftriaxone and acute-phase reactant activation during infection, however, also may have interfered with the patient's cyclosporine elimination. Azithromycin generally is considered unlikely to interact with cyclosporine. Nonetheless, practitioners should be aware of this possibility and should monitor cyclosporine levels closely, especially in critically ill patients who have other complications.
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Affiliation(s)
- R L Page
- Department of Pharmacy Practice, School of Pharmacy University of Colorado Health Sciences Center, Denver 80262, USA
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Vasquez E, Pollak R, Benedetti E. Clotrimazole increases tacrolimus blood levels: a drug interaction in kidney transplant patients. Clin Transplant 2001; 15:95-9. [PMID: 11264634 DOI: 10.1034/j.1399-0012.2001.150203.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In order to substantiate a previous case report of a drug interaction between tacrolimus and clotrimazole, we randomly assigned tacrolimus-treated renal allograft recipients to therapy with either clotrimazole or nystatin for oral thrush prophylaxis immediately following transplantation. Patients receiving other agents known to interact with cytochrome P450 were excluded from the study. The clotrimazole group consisted of 17 patients and the nystatin group, which served as the control group, consisted of 18 patients. An oral loading dose (approximately 0.3 mg/kg) of tacrolimus was given pre-operatively. Post-transplant, tacrolimus (approximately 0.15 mg/kg) was orally administered twice daily. Clotrimazole therapy consisted of a 10-mg troche administered three times daily. Nystatin therapy consisted of the oral suspension (5 mL) administered as a 'swish and swallow' four times daily. We evaluated tacrolimus trough blood levels and tacrolimus doses on days 1, 3, 5, and 7 following transplantation. On post-transplant day 1, mean tacrolimus trough levels did not differ between clotrimazole- and nystatin-treated patients. Mean tacrolimus blood trough levels were significantly higher in clotrimazole-treated patients on days 3, 5, and 7 post-transplant, 42+/-14, 53+/-7, and 33+/-17 ng/mL, respectively, compared to 15+/-8, 15+/-7, and 14+/-6 ng/mL in nystatin-treated patients (p<0.05). The mean tacrolimus dose was significantly lower in the clotrimazole group by day 7 post-transplant (p<0.05). We conclude that clotrimazole therapy may cause a significant rise in tacrolimus trough blood levels. Recognition of this potential drug interaction is essential to minimize tacrolimus-associated toxicities in the early post-transplant period.
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Affiliation(s)
- E Vasquez
- Department of Pharmacy Practice, University of Illinois at Chicago, Chicago, IL, USA
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24
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Abstract
OBJECTIVE To describe the current drug interaction profiles for the commonly used macrolides in the US and Europe, and to comment on the clinical impact of these interactions. DATA SOURCES A MEDLINE search (1975-1998) was performed to identify all pertinent studies, review articles, and case reports. When appropriate information was not available in the literature, data were obtained from the product manufacturers. STUDY SELECTION All available data were reviewed to provide an unbiased account of possible drug interactions. DATA EXTRACTION Data for some of the interactions were not available from the literature, but were available from abstracts or company-supplied materials. Although the data were not always explicit, the best attempt was made to deliver pertinent information that clinical practitioners would need to formulate practice opinions. When more in-depth information was supplied in the form of a review or study report, a thorough explanation of pertinent methodology was supplied. DATA SYNTHESIS Several clinically significant drug interactions have been identified since the approval of erythromycin. These interactions usually were related to the inhibition of the cytochrome P450 enzyme systems, which are responsible for the metabolism of many drugs. The decreased metabolism by the macrolides has in some instances resulted in potentially severe adverse events. The development and marketing of newer macrolides are hoped to improve the drug interaction profile associated with this class. However, this has produced variable success. Some of the newer macrolides demonstrated an interaction profile similar to that of erythromycin; others have improved profiles. The most success in avoiding drug interactions related to the inhibition of cytochrome P450 has been through the development of the azalide subclass, of which azithromycin is the first and only to be marketed. Azithromycin has not been demonstrated to inhibit the cytochrome P450 system in studies using a human liver microsome model, and to date has produced none of the classic drug interactions characteristic of the macrolides. CONCLUSIONS Most of the available data regarding macrolide drug interactions are from studies in healthy volunteers and case reports. These data suggest that clarithromycin appears to have an interaction profile similar to that of erythromycin. Given this similarity, it is important to consider the interaction profile of clarithromycin when using erythromycin. This is especially necessary as funds for further studies of a medication available in generic form (e.g., erythromycin) are limited. Azithromycin has produced few clinically significant interactions with any agent cleared through the cytochrome P450 enzyme system. Although the available data are promising, the final test should come from studies conducted in patients who are taking potentially interacting compounds on a chronic basis.
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Affiliation(s)
- M P Pai
- Clinical Pharmacology Research Center, Bassett Healthcare, Cooperstown, NY 13326, USA
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25
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Benet LZ, Izumi T, Zhang Y, Silverman JA, Wacher VJ. Intestinal MDR transport proteins and P-450 enzymes as barriers to oral drug delivery. J Control Release 1999; 62:25-31. [PMID: 10518631 DOI: 10.1016/s0168-3659(99)00034-6] [Citation(s) in RCA: 230] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Cytochrome P-450 3A4 (CYP3A4), the major phase I drug metabolizing enzyme in humans, and the multidrug efflux pump, MDR or P-glycoprotein (P-gp), are present at high levels in the villus tip enterocytes of the small intestine, the primary site of absorption for orally administered drugs. These proteins are induced or inhibited by many of the same compounds and demonstrate a broad overlap in substrate and inhibitor specificities, suggesting that they act as a concerted barrier to drug absorption. A series of studies from our laboratory of cyclosporine and tacrolimus in humans and a novel cysteine protease inhibitor in rats, dosed concomitantly with inhibitors and inducers of CYP3A4 and P-gp, suggest that gut extraction can be modeled using measures of intestinal metabolism and absorption rate, the latter reflecting changes in P-gp. Results evaluating a preliminary model applied to the CYP3A substrate drugs midazolam, indinavir, saquinavir, and rifabutin suggest that the model may be useful for predicting in vivo intestinal metabolism from in vitro data.
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Affiliation(s)
- L Z Benet
- Department of Biopharmaceutical Sciences, University of California, San Francisco, CA 94143-0446, USA
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26
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Ito K, Kusuhara H, Sugiyama Y. Effects of intestinal CYP3A4 and P-glycoprotein on oral drug absorption--theoretical approach. Pharm Res 1999; 16:225-31. [PMID: 10100307 DOI: 10.1023/a:1018872207437] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE To evaluate the effects of gut metabolism and efflux on drug absorption by simulation studies using a pharmacokinetic model involving diffusion in epithelial cells. METHODS A pharmacokinetic model for drug absorption was constructed including metabolism by CYP3A4 inside the epithelial cells, P-gp-mediated efflux into the lumen, intracellular diffusion from the luminal side to the basal side, and subsequent permeation through the basal membrane. Partial differential equations were solved to yield an equation for the fraction absorbed from gut to the blood. Effects of inhibition of CYP3A4 and/or P-gp on the fraction absorbed were simulated for a hypothetical substrate for both CYP3A4 and P-gp. RESULTS The fraction absorbed after oral administration was shown to increase following inhibition of P-gp. This increase was more marked when the efflux clearance of the drug was greater than the sum of the metabolic and absorption clearances and when the intracellular diffusion constant was small. Furthermore, it was demonstrated that the fraction absorbed was synergistically elevated by simultaneous inhibition of both CYP3A4 and P-gp. CONCLUSIONS The analysis using our present diffusion model is expected to allow the prediction of in vivo intestinal drug absorption and related drug interactions from in vitro studies using human intestinal microsomes, gut epithelial cells, CYP3A4-expressed Caco-2 cells, etc.
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Affiliation(s)
- K Ito
- School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
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27
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Kim YH, Yoon YR, Kim YW, Shin JG, Cha IJ. Effects of rifampin on cyclosporine disposition in kidney recipients with tuberculosis. Transplant Proc 1998; 30:3570-2. [PMID: 9838563 DOI: 10.1016/s0041-1345(98)01139-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Y H Kim
- Inje University College of Medicine, Division of Nephrology, Pusan Paik Hospital, South Korea
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28
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Christians U, Jacobsen W, Floren LC. Metabolism and drug interactions of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors in transplant patients: are the statins mechanistically similar? Pharmacol Ther 1998; 80:1-34. [PMID: 9804052 DOI: 10.1016/s0163-7258(98)00016-3] [Citation(s) in RCA: 167] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
3-Hydroxy-3-methylglutaryl coenzyme A reductase (EC 1.1.1.88) inhibitors are the most effective drugs to lower cholesterol in transplant patients. However, immunosuppressants and several other drugs used after organ transplantation are cytochrome P4503A (CYP3A, EC 1.14.14.1) substrates. Pharmacokinetic interaction with some of the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, specifically lovastatin and simvastatin, leads to an increased incidence of muscle skeletal toxicity in transplant patients. It is our objective to review the role of drug metabolism and drug interactions of lovastatin, simvastatin, pravastatin, fluvastatin, atorvastatin, and cerivastatin. In the treatment of transplant patients, from a drug interaction perspective, pravastatin, which is not significantly metabolized by CYP enzymes, and fluvastatin, presumably a CYP2C9 substrate, compare favorably with the other statins for which the major metabolic pathways are catalyzed by CYP3A.
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Affiliation(s)
- U Christians
- Department of Biopharmaceutical Sciences, School of Pharmacy, University of California at San Francisco, 94143-0446, USA
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29
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Douglas LR, Douglass JB, Sieck JO, Smith PJ. Oral management of the patient with end-stage liver disease and the liver transplant patient. ORAL SURGERY, ORAL MEDICINE, ORAL PATHOLOGY, ORAL RADIOLOGY, AND ENDODONTICS 1998; 86:55-64. [PMID: 9690246 DOI: 10.1016/s1079-2104(98)90150-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The patient with end-stage liver disease who is in need of a liver transplant should have a pretransplant dental evaluation. Such a patient faces lifelong immunosuppression with an increased risk of infection. This article discusses both the need for control of oral diseases before liver transplantation and guidelines for oral care in the immediately postoperative and long-term transplant patient. Specific indications for antibiotic prophylaxis and antibiotic regimens are presented; in addition, adverse reactions and side effects of immunosuppressant drugs are discussed. Pertinent drug interactions salient to the dental management of patients with end-stage liver disease are reviewed, and specific management recommendations for these patients are presented.
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Affiliation(s)
- L R Douglas
- Department of Dentistry, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
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30
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Schuetz EG, Yasuda K, Arimori K, Schuetz JD. Human MDR1 and mouse mdr1a P-glycoprotein alter the cellular retention and disposition of erythromycin, but not of retinoic acid or benzo(a)pyrene. Arch Biochem Biophys 1998; 350:340-7. [PMID: 9473310 DOI: 10.1006/abbi.1997.0537] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The intracellular concentration of many steroids and xenobiotics is influenced by the membrane protein P-glycoprotein (Pgp). It has been inferred that the intracellular retention of many drugs that upregulate Pgp or modulate Pgp function might also be affected by Pgp. However, the ability of Pgp to influence the translocation of these drugs needs to be established to understand Pgp's influence upon their pharmacological effect. We utilized two approaches to determine the interaction of several agents with Pgp: (a) an in vitro system, LLC-PK1 cell lines and derivative LLC cell lines stably expressing on the apical membrane either mouse mdr1a or human MDR1 Pgp grown as polarized epithelium in transwell culture to measure translocation of radiolabeled drugs; and (b) an in vivo system, mdr1a nullizygous and wild-type animals, to compare the contribution of Pgp to in vivo distribution of radiolabeled drugs. In combination these complementary approaches identified erythromycin as a drug whose intracellular retention is influenced by Pgp, while the intracellular accumulation and tissue distribution of retinoic acid and benzo(a)pyrene were unaffected by Pgp.
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Affiliation(s)
- E G Schuetz
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
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31
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Abstract
There are a number of areas in which advances have been made over the last few years in the area of pharmacokinetics in the elderly. There is increasing understanding of the diversity of cytochrome P450s (CYP) and the variability of the age-related decline in CYP activity. This has helped to explain some of the interindividual variability in drug metabolism with age. The importance of ethnic differences has emerged, but specific work is needed in this area in the elderly. Differences in the handling of chiral compounds has been reported but as yet no clinically important findings that may lead to a change in clinical practice have emerged. The emerging importance of extrahepatic drug metabolism, especially in the intestine, has added a new complexity to our understanding of pharmacokinetics. The issue of frailty is also discussed in this article. Whether it will be of value at the bedside has yet to emerge. Nonetheless, as a concept, recent data has supported its potential use to define those more at risk of clinically meaningful pharmacokinetic alterations. Other advances have included the appreciation that selectivity in induction and inhibition in the elderly are due to the existence of multiple CYP forms. Similarly, the role of these various enzymes in disease is also improving our clinical understanding, as exemplified in Parkinson's disease.
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Affiliation(s)
- M T Kinirons
- Clinical Age Research Unit, King's College School of Medicine and Dentistry, London, England
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32
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Contributions of hepatic and intestinal metabolism and P-glycoprotein to cyclosporine and tacrolimus oral drug delivery. Adv Drug Deliv Rev 1997; 27:201-214. [PMID: 10837558 DOI: 10.1016/s0169-409x(97)00043-4] [Citation(s) in RCA: 220] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The objective of this section is to evaluate the contributions of hepatic metabolism, intestinal metabolism and intestinal p-glycoprotein to the pharmacokinetics of orally administered cyclosporine and tacrolimus. Cyclosporine and tacrolimus are metabolized primarily by cytochrome P450 3A4 (CYP3A4) in the liver and small intestine. There is also evidence that cyclosporine is metabolized to a lesser extent by cytochrome P450 3A5 (CYP3A5). Cyclosporine and tacrolimus are also substrates for p-glycoprotein, which acts as a counter-transport pump, actively transporting cyclosporine and tacrolimus back into the intestinal lumen. Traditional teaching of clinical drug metabolism has been that hepatic metabolism is of primary importance, and other sites of metabolism play a relatively minor role. It appears as though intestinal metabolism plays a much greater role in the pharmacokinetics of orally administered drugs than previously thought. Intestinal metabolism may account for as much as 50% of oral cyclosporine metabolism. There are at least two components of intestinal metabolism for cyclosporine and tacrolimus, intestinal CYP3A4/CYP3A5 and intestinal p-glycoprotein activities. The quantity of intestinal enzymes, although highly variable, do not appear to be the key to explaining the variability of oral cyclosporine pharmacokinetics in kidney transplant patients. However, the quantity of intestinal p-glycoprotein accounts for approximately 17% of the variability in oral cyclosporine pharmacokinetics. It may be that p-glycoprotein maximizes drug exposure to intestinal enzymes, thus decreasing the importance of enzyme quantity. Since cyclosporine's FDA approval in 1983, there have been many reports of clinically significant drug interactions of other agents when given concomitantly with cyclosporine. With the FDA approval of tacrolimus in 1994, a similar pattern of clinically significant drug interactions appears to be emerging. It seems that compounds that alter (either induce or inhibit) CYP3A4 and/or p-glycoprotein will alter the oral pharmacokinetics of cyclosporine and tacrolimus. It should be expected that, until further data are available, the drugs which interact with cyclosporine will also interact with tacrolimus.
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33
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Jones TE. The use of other drugs to allow a lower dosage of cyclosporin to be used. Therapeutic and pharmacoeconomic considerations. Clin Pharmacokinet 1997; 32:357-67. [PMID: 9160170 DOI: 10.2165/00003088-199732050-00002] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Since its discovery in 1970, and introduction into clinical practice in 1978, cyclosporin has become the most important immunosuppressive drug used to prevent organ transplant rejection. This has been achieved by virtue of the improved graft survival rates and adverse effect profiles in patients when compared with that of the older agents. Cyclosporin is substantially more expensive (both to provide and to monitor) however, and the magnitude of these costs may preclude its use, particularly where the transplant recipient is required to pay. Cyclosporin has a complex pharmacokinetic profile with poor absorption, extensive metabolism to more than 30 metabolites and considerable inter- and intrapatient variability. Many transplant centres routinely use drugs ("cyclosporin-sparing agents') to allow a reduction in the dosage of cyclosporin while maintaining therapeutic blood cyclosporin concentrations. The use of a second drug to affect the pharmacokinetic profile of a primary drug is not new, but the use of cyclosporin-sparing agents is a departure from previous practices in that this coprescription is primarily for economic reasons. The decision to use these agents (and the choice of agent) is based upon economic and other factors including the extent of the cyclosporin-sparing effect, the potential for additional therapeutic benefit and/or adverse effects. The coprescription of cyclosporin-sparing agents is ethically more acceptable where the transplant recipient is the economic beneficiary but where the savings accrue to a third party it is more difficult. Benefits to the community at large must be balanced against the risk of adverse effects to the patient. The use of cyclosporin-sparing agents may reduce compliance and hence, jeopardise transplant and/or recipient outcomes. The transplant recipient must be informed about the reasons for their use and advised to consult an experienced physician or pharmacist before altering the established drug regimen.
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Affiliation(s)
- T E Jones
- Pharmacy Department, Queen Elizabeth Hospital, Woodville South, Australia
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34
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Iatsimirskaia E, Tulebaev S, Storozhuk E, Utkin I, Smith D, Gerber N, Koudriakova T. Metabolism of rifabutin in human enterocyte and liver microsomes: kinetic parameters, identification of enzyme systems, and drug interactions with macrolides and antifungal agents. Clin Pharmacol Ther 1997; 61:554-62. [PMID: 9164417 DOI: 10.1016/s0009-9236(97)90135-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Biotransformation of rifabutin, an antibiotic used for treatment of tuberculosis in patients infected with the human immunodeficiency virus (HIV), and its interactions with some macrolide and antifungal agents were studied in human intestinal and liver microsomes. Both liver and enterocyte microsomes metabolized rifabutin to 25-O-deacetylrifabutin, 27-O-demethylrifabutin, and 20-, 31-, and 32-hydroxyrifabutin. The same products (except 25-O-deacetylrifabutin) were formed by microsomes from lymphoblastoid cells that contained expressed CYP3A4. The apparent Michaelis-Menten constant (Km); approximately 10 to 12 mumol/L) and maximal velocity (Vmax; approximately 100 pmol/min/mg of protein) values for CYP-mediated metabolism were similar in liver and enterocyte microsomes. Deacetylation of rifabutin (Km approximately 16 to 20 mumol/L and Vmax approximately 50 to 100 pmol/min/mg of protein) was catalyzed by microsomal cholinesterase. Clarithromycin, ketoconazole, and fluconazole inhibited CYP-mediated metabolism of rifabutin in enterocyte microsomes equally or more potently than in liver microsomes but had no effect on cholinesterase activity. Azithromycin did not inhibit in vitro metabolism of rifabutin. This study provides evidence that CYP3A4 and cholinesterase are major enzymes that biotransform rifabutin in humans and that intestinal CYP3A4 contributes significantly to rifabutin presystemic first-pass metabolism and drug interactions with macrolide and antifungal agents.
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Affiliation(s)
- E Iatsimirskaia
- Department of Pharmacology, Ohio State University, Columbus 43210, USA
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Ketter TA, Flockhart DA, Post RM, Denicoff K, Pazzaglia PJ, Marangell LB, George MS, Callahan AM. The emerging role of cytochrome P450 3A in psychopharmacology. J Clin Psychopharmacol 1995; 15:387-98. [PMID: 8748427 DOI: 10.1097/00004714-199512000-00002] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Recent advances in molecular pharmacology have allowed the characterization of the specific isoforms that mediate the metabolism of various medications. This information can be integrated with older clinical observations to begin to develop specific mechanistic and predictive models of psychotropic drug interactions. The polymorphic cytochrome P450 2D6 has gained much attention, because competition for this isoform is responsible for serotonin reuptake inhibitor-induced increases in tricyclic antidepressant concentrations in plasma. However, the cytochrome P450 3A subfamily and the 3A3 and 3A4 isoforms (CYP3A3/4) in particular are becoming increasingly important in psychopharmacology as a result of their central involvement in the metabolism of a wide range of steroids and medications, including antidepressants, benzodiazepines, calcium channel blockers, and carbamazepine. The inhibition of CYP3A3/4 by medications such as certain newer antidepressants, calcium channel blockers, and antibiotics can increase the concentrations of CYP3A3/4 substrates, yielding toxicity. The induction of CYP3A3/4 by medications such as carbamazepine can decrease the concentrations of CYP3A3/4 substrates, yielding inefficiency. Thus, knowledge of the substrates, inhibitors, and inducers of CYP3A3/ and other cytochrome P450 isoforms may help clinicians to anticipate and avoid pharmacokinetic drug interactions and improve rational prescribing practices.
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Affiliation(s)
- T A Ketter
- Biological Psychiatry Branch, National Institute of Mental Health, Bethesda, Maryland 20892, USA
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Abstract
Cyclosporine, tacrolimus, and mycophenolate are selective immunosuppressive agents commonly prescribed to prevent organ rejection. Drug interactions that increase their blood levels could expose transplant recipients to serious side effects, while drug interactions that decrease their blood levels may cause rejection episodes as a result of inadequate immunosuppression. Cyclosporine and tacrolimus are metabolized by the cytochrome P-450 enzyme system. Drugs that induce, inhibit, or compete for the same cytochrome P-450 enzyme could affect blood levels of these immunosuppressive agents.
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Affiliation(s)
- R Seifeldin
- Bouve College of Pharmacy and Health Sciences, Northeastern University, Boston, Massachusetts, USA
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Wu CY, Benet LZ, Hebert MF, Gupta SK, Rowland M, Gomez DY, Wacher VJ. Differentiation of absorption and first-pass gut and hepatic metabolism in humans: studies with cyclosporine. Clin Pharmacol Ther 1995; 58:492-7. [PMID: 7586942 DOI: 10.1016/0009-9236(95)90168-x] [Citation(s) in RCA: 275] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The low and variable bioavailability of cyclosporine has been attributed to poor absorption. However, recent studies have suggested that intestinal first-pass metabolism exerts a significant effect on bioavailability. We describe theory and methods to differentiate the contribution from oral absorption and intestinal and hepatic metabolism to overall cyclosporine bioavailability. Analysis of data from previous studies in our laboratories shows that in the absence of intestinal metabolism, cyclosporine absorption from its presently available dosage form averages at least 65% +/- 12% in healthy volunteers and 77% +/- 19% in kidney transplant patients. Analysis also suggests that the extraction ratio for cyclosporine in the gut is approximately twice the hepatic extraction and that cyclosporine absorption does not present a problem, with an average of 86% of the drug absorbed intact from its commercially available product in healthy volunteers. The boundary condition analysis described should have broad application in the differentiation of factors responsible for poor bioavailability.
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Affiliation(s)
- C Y Wu
- Department of Pharmacy, University of California, San Francisco 94143-0446, USA
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38
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Abstract
OBJECTIVE To describe the current drug interaction profiles for all approved and investigational macrolide and azalide antimicrobials, and to comment on the clinical impact of these interactions when appropriate. DATA SOURCES MEDLINE was searched to identify all pertinent studies, review articles, and case reports from 1975 to 1995. When appropriate information was not available in the literature, data were obtained from the product manufacturers. STUDY SELECTION All available data were reviewed to give an unbiased account of possible drug interactions. DATA EXTRACTION Data for some of the interactions were not available from the literature, but were available from abstracts or from company-supplied materials. Although the data were not always entirely explicative, the best attempt was made to deliver the pertinent information that clinical practitioners would need to formulate practice opinions. When more in-depth information was supplied in the form of a review or study report, a thorough explanation of pertinent methodology was supplied. DATA SYNTHESIS Since the introduction of erythromycin into clinical practice, there have been several clinically significant drug interactions identified throughout the literature associated with this drug. These interactions have been caused mostly by inhibition of the CYP3A subclass of hepatic enzymes, thereby decreasing the metabolism of any other agent given concurrently that is also cleared through this mechanism. With the development and marketing of several new macrolides, it was hoped that the drug interaction profile associated with this class would improve. This has been met with variable success. Although some of the extensions of the 14-membered ring macrolides have shown an incidence of interactions equal to that of erythromycin, others have shown improved profiles. In contrast, the 16-membered ring macrolides have demonstrated a much improved, though not absent, interaction profile. The most success in avoiding drug interactions through structure modification has been accomplished with the development of the azalide class, of which azithromycin is the first to be approved for marketing. This agent has to date produced none of the classic drug interactions that most macrolides have demonstrated in patient care. CONCLUSIONS The introduction of new 14- and 16-membered ring macrolides appears to have had a variable effect in modifying the incidence of drug interactions associated with this class. Azithromycin, a member of the new azalide class, has to date produced fewer clinically significant interactions than other azalides with any agent that is cleared through the CYP3A system.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- G W Amsden
- Clinical Drug Research Center, Saint Vincent Hospital, Worcester, MA 01604, USA
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Abstract
Macrolide antibiotics can interact adversely with commonly used drugs, usually by altering metabolism due to complex formation and inhibition of cytochrome P-450 IIIA4 (CYP3A4) in the liver and enterocytes. In addition, pharmacokinetic drug interactions with macrolides can result from their antibiotic effect on microorganisms of the enteric flora, and through enhanced gastric emptying due to a motilin-like effect. Macrolides may be classified into 3 different groups according to their affinity for CYP3A4, and thus their propensity to cause pharmacokinetic drug interactions. Troleandomycin, erythromycin and its prodrugs decrease drug metabolism and may produce drug interactions (group 1). Others, including clarithromycin, flurithromycin, midecamycin, midecamycin acetate (miocamycin; ponsinomycin), josamycin and roxithromycin (group 2) rarely cause interactions. Azithromycin, dirithromycin, rikamycin and spiramycin (group 3) do not inactivate CYP3A4 and do not engender these adverse effects. Drug interactions with carbamazepine, cyclosporin, terfenadine, astemizole and theophylline represent the most frequently encountered interactions with macrolide antibiotics. If the combination of a macrolide and one of these compounds cannot be avoided, serum concentrations of concurrently administered drugs should be monitored and patients observed for signs of toxicity. Rare interactions and those of dubious clinical importance are those with alfentanil and sufentanil, antacids and cimetidine, oral anticoagulants, bromocriptine, clozapine, oral contraceptive steroids, digoxin, disopyramide, ergot alkaloids, felodipine, glibenclamide (glyburide), levodopa/carbidopa, lovastatin, methylprednisolone, phenazone (antipyrine), phenytoin, rifabutin and rifampicin (rifampin), triazolam and midazolam, valproic acid (sodium valproate) and zidovudine.
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40
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Ducharme MP, Warbasse LH, Edwards DJ. Disposition of intravenous and oral cyclosporine after administration with grapefruit juice. Clin Pharmacol Ther 1995; 57:485-91. [PMID: 7768070 DOI: 10.1016/0009-9236(95)90032-2] [Citation(s) in RCA: 249] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE To examine the effect of grapefruit juice on the disposition of cyclosporine after administration of oral and intravenous doses to healthy male subjects. METHODS Subjects received two oral doses of cyclosporine (7.5 mg/kg) and two intravenous doses (2.5 mg/kg infused for 3 hours), with each dose separated by a 1-week washout period. Grapefruit juice (250 ml) was ingested immediately before one oral and one intravenous dose and again 2 hours later. Blood samples were collected for a 24-hour period, and whole blood concentrations of cyclosporine were measured with use of a specific monoclonal radioimmunoassay. RESULTS Grapefruit juice had no effect on any pharmacokinetic parameter when given with intravenous cyclosporine. After oral administration, grapefruit juice significantly increased peak concentration (936 versus 1340 ng/ml), as well as area under the curve (6722 versus 10,730 ng . hr/ml) but had no effect on elimination half-life. Absolute bioavailability of cyclosporine was increased from 0.22 to 0.36 (average increase, 62%) by grapefruit juice. CONCLUSIONS The lack of effect on systemic clearance after intravenous cyclosporine suggests that grapefruit juice improves oral bioavailability by increasing absorption or reducing gut wall metabolism. The latter is more likely in view of studies that suggest significant gut wall metabolism of cyclosporine by CYP3A enzymes known to be inhibited by components of grapefruit juice.
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Affiliation(s)
- M P Ducharme
- College of Pharmacy and Allied Health Professions, Wayne State University, Detroit, MI 48202, USA
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Zylber-Katz E. Multiple drug interactions with cyclosporine in a heart transplant patient. Ann Pharmacother 1995; 29:127-31. [PMID: 7756709 DOI: 10.1177/106002809502900204] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
OBJECTIVE To report multiple drug interactions with cyclosporine in a heart transplant recipient. CASE SUMMARY A 53-year-old man underwent heart transplantation in December 1990. Immunosuppression therapy consisted of prednisone, azathioprine, and cyclosporine 300 mg/d. For 5 months, the trough specific cyclosporine (parent compound) concentration was stable (range 211-226 ng/mL). More recently, he developed a productive cough accompanied by high fever, chills, and weakness and was admitted to a hospital near his home. Antituberculosis therapy was advised including rifampin and isoniazid. After a week, erythromycin 3.6 g/d i.v. was added. After 10 days of the combined therapy he was transferred to our hospital, where the first cyclosporine blood concentrations measured were 77 and 238 ng/mL for specific and total cyclosporine (parent drug + metabolites). Because of the low cyclosporine blood concentration, the dose was increased to 400 mg/d. In light of negative sputum smears for acid-fast bacilli and culture, the rifampin/isoniazid therapy was withdrawn; the erythromycin was continued. At this time, the specific cyclosporine blood concentration rose to 934 ng/mL and the total cyclosporine concentration reached 1503 ng/mL. High cyclosporine blood concentrations were measured during the intravenous erythromycin treatment period, even though the cyclosporine dose had been decreased to 150 mg/d. A further increase in cyclosporine concentration was observed when erythromycin was given orally (4.0 g/d). The cyclosporine dose was then discontinued for 2 days and started again at 50 mg/d until the end of the erythromycin treatment period. The patient recovered, the cyclosporine dose was increased to 100 mg/d, and on regular monitoring the cyclosporine blood concentrations were within the therapeutic range (100-400 ng/mL for specific and 250-1000 ng/mL for total cyclosporine). DISCUSSION Cyclosporine is metabolized almost completely in the liver by the cytochrome P-450IIIA enzyme system. Drugs such as rifampin and erythromycin, which are known to be inducers or substrates of cytochrome P-450IIIA, have the potential to alter cyclosporine blood concentrations. The present case shows a multiple drug interaction with cyclosporine. Coadministration of rifampin/isoniazid and cyclosporine for a week, and erythromycin for the last 4 days, resulted in low cyclosporine blood concentrations, probably because of microsomal induction by rifampin. When the rifampin/isoniazid treatment was discontinued, the cyclosporine blood concentrations rose, indicating the interacting effect of intravenous erythromycin. This effect was even more pronounced when therapy was changed from intravenous to oral administration. Erythromycin, a substrate that is metabolized with great affinity by the cytochrome P-450IIIA enzyme, prolonged the elimination of cyclosporine by competing for the same site of metabolism. CONCLUSIONS Awareness of potential cyclosporine drug interactions in organ transplant patients of great clinical importance. Regular monitoring of cyclosporine blood concentrations and renal function are essential to detect such interactions, to allow adjustment of drug dosage, and to reduce toxicity and enhance therapeutic effect, in particular in patients coadministered the many drugs known to have pharmacokinetic interactions with cyclosporine.
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Affiliation(s)
- E Zylber-Katz
- Clinical Pharmacology Laboratory, Hadassah University Hospital, Jerusalem, Israel
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Jensen C, Jordan M, Shapiro R, Scantlebury V, Hakala T, Fung J, Starzl T, Venkataramanan R. Interaction between tacrolimus and erythromycin. Lancet 1994; 344:825. [PMID: 7521928 DOI: 10.1016/s0140-6736(94)92383-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Holt DW, Johnston A, Roberts NB, Tredger JM, Trull AK. Methodological and clinical aspects of cyclosporin monitoring: report of the Association of Clinical Biochemists task force. Ann Clin Biochem 1994; 31 ( Pt 5):420-46. [PMID: 7832569 DOI: 10.1177/000456329403100503] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- D W Holt
- Analytical Unit, St George's Hospital Medical School, London, UK
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Moral A, Navasa M, Rimola A, García-Valdecasas JC, Grande L, Visa J, Rodés J. Erythromycin ototoxicity in liver transplant patients. Transpl Int 1994. [DOI: 10.1111/j.1432-2277.1994.tb01279.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Moral A, Navasa M, Rimola A, García-Valdecasas JC, Grande L, Visa J, Rodés J. Erythromycin ototoxicity in liver transplant patients. Transpl Int 1994; 7:62-4. [PMID: 8117405 DOI: 10.1007/bf00335665] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We report on three liver transplant patients who developed erythromycin-related ototoxicity. This complication has been described in renal transplant patients and in patients with liver dysfunction, but to our knowledge it has not yet been reported in liver transplant patients. The influence of hepatic dysfunction, common renal failure, and the interaction between cyclosporin and erythromycin in the development of erythromycin ototoxicity are discussed.
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Affiliation(s)
- A Moral
- Department of Surgery, Hospital Clinic, University of Barcelona, Spain
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Ducharme MP, Provenzano R, Dehoorne-Smith M, Edwards DJ. Trough concentrations of cyclosporine in blood following administration with grapefruit juice. Br J Clin Pharmacol 1993; 36:457-9. [PMID: 12959294 PMCID: PMC1364619 DOI: 10.1111/j.1365-2125.1993.tb00395.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Components of grapefruit juice have been shown to inhibit CYP3A4 activity, the enzyme involved in cyclosporine metabolism. Eleven medically stable patients (seven males, four females) receiving cyclosporine following kidney transplantation were instructed to take their usual dose of cyclosporine with water for 1 week (Phase 1), with grapefruit juice (8 ounces) for 1 week (Phase 2) and again with water for 1 week (Phase 3). Trough blood samples were obtained at the end of each phase for measurement of cyclosporine concentration using a specific monoclonal whole blood radioimmunoassay. Cyclosporine trough concentrations averaged 116.9 +/- 51.6 ng ml(-1) in the first phase, 145.3 +/- 44.7 ng ml(-1) with grapefruit juice (P < 0.05 compared with the first and third phases) and 111.2 +/- 56.1 ng ml(-1) in the third phase. Cyclosporine concentrations increased in 8 of 11 patients when given with grapefruit juice (mean increase 32%; range -4 to 97%) and declined in 10 of 11 when subjects resumed taking cyclosporine with water (mean decrease 27%). These results suggest that grapefruit juice increases trough concentrations of cyclosporine in blood, possibly by inhibiting pre-hepatic gut wall metabolism, and could be useful in optimizing therapy with this drug.
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Affiliation(s)
- M P Ducharme
- Department of Pharmacy Practice, College of Pharmacy and Allied Health Professions, Wayne State University, Detroit, MI 48202, USA
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Hughes CM, Swanton JG, Collier PS. Cyclosporin A and erythromycin: a study of a drug interaction in the in situ perfused rat liver model. Biopharm Drug Dispos 1993; 14:615-25. [PMID: 8251616 DOI: 10.1002/bdd.2510140708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Using the in situ perfused rat liver model, the effect of erythromycin (Ery) on the disposition of cyclosporin A (CyA) and the major human metabolite, AM1, was investigated. Prior to perfusion experiments, oral dosing was carried out for three days on three groups of male Sprague-Dawley rats (300-350 g), involving pretreatment with water (control and H2O/Ery groups) or erythromycin (Ery oral group). On the fourth day, perfusion experiments took place using standard techniques, with the addition of 20 mg Ery to the H2O/Ery and Ery oral groups, and 2.5 mg CyA to all groups. Perfusate and bile samples were collected and assayed for CyA and AM1 by HPLC. Results indicated that inhibition of CyA metabolism had occurred as the CyA concentration in perfusate was significantly higher in both Ery groups at all times compared to the control group, and the levels of AM1 in both perfusate and bile were significantly lower than in the control group. There was also a marked reduction in the apparent metabolic clearance of CyA in the Ery groups. It was concluded that AM1 production had been inhibited by Ery, the most likely mechanism being inhibition of the isoenzyme CYP3A with which Ery forms a stable complex.
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Affiliation(s)
- C M Hughes
- School of Pharmacy, Queen's University of Belfast, Northern Ireland, U.K
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Cyclosporin a in rheumatoid arthritis: A critical review. Inflammopharmacology 1993. [DOI: 10.1007/bf02659091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Abstract
OBJECTIVE To present cases supporting the hypothesis that fluconazole inhibition of cyclosporine metabolism is dose-dependent. DESIGN Case reports. PATIENTS AND INTERVENTIONS One renal-pancreatic transplant patient taking fluconazole 100 and 300 mg/d for 37 and 17 days, respectively; four bone marrow transplant recipients taking fluconazole 100 mg/d as antifungal prophylaxis and five other concurrent nonmatched recipients whose antifungal prophylactic agent is nystatin mouthwash. All of these patients underwent transplantation during the same period. RESULTS There was a sharp rise in cyclosporine trough concentration (ng/mL), concentration:dose ratio (ng.mL-1/mg.kg-1), and serum creatinine concentration (mumol/L) in the renal-pancreatic transplantation patient taking fluconazole 300 mg/d. No such increase occurred at 100 mg/d. No significant alterations in cyclosporine concentration:dose ratio were seen in the patients undergoing bone marrow transplantation and receiving fluconazole 100 mg/d. CONCLUSIONS The case of the renal-pancreatic transplantation patient shows a characteristic interaction profile, and it supports the hypothesis of a dose-dependent interaction between cyclosporine and fluconazole. Given the nephrotoxic potential of the immunosuppressant drug, dosage reduction and closer monitoring of cyclosporine concentrations and/or renal function in patients receiving fluconazole dosages greater than 200 mg/d must be considered.
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Affiliation(s)
- J A López-Gil
- Clinical Pharmacology Service, Hospital Universitario Marqués de Valdecilla, Santander, Spain
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50
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Abstract
The immunosuppressant cyclosporin, a cyclic undecapeptide, is metabolized to more than 30 metabolites. Cytochrome P450IIIA enzymes located in liver and small intestine are responsible for the biotransformation of cyclosporin and its metabolites and are the site of several drug interactions. It is still under discussion, whether the cyclosporin metabolites are involved in the immunosuppressive and/or toxic activities of cyclosporin. While isolated metabolites show not more than 10-20% of the activity of the mother compound in vitro, metabolite combinations have additive and synergistic effects. Isolated metabolites show no toxic effects in rat models while there is an association between metabolite blood concentrations and cyclosporin toxicity in several clinical studies. Possible mechanisms for the toxic effect of cyclosporin metabolites are covalent binding to macromolecules in liver and kidney, alteration of the cytochrome P450 pattern in liver and kidney, increased endothelin production in the kidney and synergistic effects of cyclosporin combinations on mesangial cells. Liver dysfunction leads to an alteration of the metabolite patterns and to increased concentrations of cyclosporin metabolites in blood. In conclusion there is evidence that cyclosporin metabolites may contribute to cyclosporin toxicity and high metabolite blood concentrations in patients should not be tolerated.
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Affiliation(s)
- U Christians
- Institut für Allgemeine Pharmakologie, Medizinische Hochschule, Hannover, Germany
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