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Kokubun H, Takigawa C, Chihara S, Hara S, Uezono Y. Population Pharmacokinetics of Methadone after Oral Administration in Japanese Patients with Cancer-Related Pain. J Pain Palliat Care Pharmacother 2020; 34:203-210. [PMID: 32870067 DOI: 10.1080/15360288.2020.1785070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Methadone tablets were approved for use in Japan in March 2013. The metabolism of methadone is complex and executed mainly by the cytochromes, CYP3A4 and CYP2B6. The aim of this study was to evaluate the pharmacokinetics of methadone upon oral administration in Japanese patients who experienced cancer-related pain. The concentration of the drug in blood samples was measured in 25 patients undergoing methadone therapy, and the factors leading to variations were investigated. A population pharmacokinetic analysis was evaluated using the Phoenix® NLMETM software. Based on this, the ALBI (albumin-bilirubin) score was identified as a significant factor that could be used to assess variations in the serum concentration of methadone, which was then incorporated into the following final model formula: clearance (L/h) = 5.38 × (ALBI score/-2.139)1.88. The results of these pharmacokinetic parameters suggested that, in clinical use, the dose of methadone should be reduced if liver function declined in patients with cancer-related pain.
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2
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Oncken C, Mead EL, Dornelas EA, Kuo CL, Sankey HZ, Kranzler HR, Thurlow S. Opioid Use and Rate of Nicotine Metabolism Among Pregnant Smokers. Nicotine Tob Res 2020; 22:1046-1050. [PMID: 31063550 DOI: 10.1093/ntr/ntz073] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 05/05/2019] [Indexed: 11/13/2022]
Abstract
INTRODUCTION Smokers who use opioids smoke more cigarettes per day (CPD) than non-opioid users, which could be due to the effects of opioids on nicotine metabolism. Moreover, nicotine metabolism increases during pregnancy, potentially making quitting more difficult for pregnant smokers. We examined nicotine metabolism and its association with opioid use (OU) and CPD in pregnant smokers. METHODS We recruited pregnant women who smoked at least 5 CPD for a clinical trial of smoking cessation. Plasma nicotine metabolite ratio (NMR; trans-3'-hydroxycotinine (3HC)/cotinine)-a biomarker of nicotine metabolism-OU (involving methadone, buprenorphine, fentanyl, oxycodone, or tramadol), and CPD were assessed at baseline. We used linear regression to examine the associations between log-transformed NMR, OU, and CPD, adjusting for race/ethnicity and menthol smoking. RESULTS Among 129 pregnant smokers, 25 (19%) were opioid users; most were maintained on methadone (n = 14). Compared to non-OU smokers, OU smokers had higher median CPD (10.0 vs. 7.0, p = .0007), serum 3HC (81.0 vs. 42.0 ng/mL, p = .0001), and NMR (0.63 vs. 0.43, p < .0001). In addition, methadone-maintained smokers had a higher median NMR than non-OU smokers (0.66 vs. 0.43, p = .0004). Adjusting for covariates, log-transformed NMR was greater in OU smokers (p = .012), specifically methadone-maintained smokers (p = .024), than non-OU smokers. CONCLUSIONS Our preliminary results show that OU is associated with a higher NMR in pregnant smokers. A larger study sample is needed to replicate this finding, examine potential mechanisms, and determine its clinical significance. IMPLICATIONS Among pregnant smokers, we observed that nicotine metabolism was significantly faster among opioid users-the majority of whom were on methadone maintenance-compared to nonusers, which could have implications for smoking cessation. Further studies are needed to replicate this finding, evaluate potential mechanisms, and determine its clinical significance.
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Affiliation(s)
- Cheryl Oncken
- Department of Medicine, University of Connecticut School of Medicine, Farmington, CT
| | - Erin L Mead
- Department of Medicine, University of Connecticut School of Medicine, Farmington, CT
| | - Ellen A Dornelas
- Division of Oncology, Department of Medicine, Hartford Hospital, Hartford, CT
| | - Chia-Ling Kuo
- Department of Medicine, University of Connecticut School of Medicine, Farmington, CT
| | - Heather Z Sankey
- Department of Obstetrics and Gynecology, UMMS-Baystate, Springfield, MA
| | - Henry R Kranzler
- Department of Psychiatry, University of Pennsylvania Perelman School of Medicine and Crescenz VAMC, Philadelphia, PA
| | - Sheila Thurlow
- Department of Medicine, University of Connecticut School of Medicine, Farmington, CT
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Packiasabapathy S, Aruldhas BW, Horn N, Overholser BR, Quinney SK, Renschler JS, Sadhasivam S. Pharmacogenomics of methadone: a narrative review of the literature. Pharmacogenomics 2020; 21:871-887. [PMID: 32705966 DOI: 10.2217/pgs-2020-0040] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Background: Methadone, a synthetic opioid with longer duration of action and lower abuse potential compared with morphine, is used to prevent opioid withdrawal, as well as to manage chronic and acute surgical pain. The variability in response to methadone has been widely recognized. The purpose of this article is to review the literature on the pharmacogenetic factors underlying this variability. Materials & methods: This is a narrative overview of the literature on the genetic variants affecting pharmacodynamics and pharmacokinetics of methadone, retrieved from searches of databases such as PubMed and google scholar. Discussion: Clinical responses to methadone may be affected by genetic variants in the opioidergic, dopaminergic and neurotrophic pathways. Polymorphisms in genes related to disposition and elimination of methadone alter the pharmacokinetics, and possibly pharmacodynamics of methadone. Cytochrome P450 enzymes and P-glycoprotein variants contribute to the interindividual variability in methadone pharmacokinetics. Evidence for single gene variants affecting methadone response remains weak. Multiple genetic variants must be considered in conjunction to improve predictive ability. Conclusion: Evidence remains scarce at this time, to recommend pharmacogenetic testing before methadone administration. Well-powered clinical studies are needed with population pharmacokinetic-pharmacodynamic modeling and multigenetic signature-based predictions to enable tailored use of methadone in clinical practice.
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Affiliation(s)
- Senthil Packiasabapathy
- Department of Anesthesia, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Blessed W Aruldhas
- Department of Anesthesia, Indiana University School of Medicine, Indianapolis, IN 46202, USA.,Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA.,Department of Pharmacology & Clinical Pharmacology, Christian Medical College, Vellore, 632002, India
| | - Nicole Horn
- Department of Anesthesia, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Brian R Overholser
- Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA.,Department of Pharmacy Practice, Purdue University College of Pharmacy, Indianapolis, IN 47907, USA
| | - Sara K Quinney
- Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA.,Department of Obstetrics & Gynecology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.,Center for Computational Biology & Bioinformatics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Janelle S Renschler
- Department of Anesthesia, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Senthilkumar Sadhasivam
- Department of Anesthesia, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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Carazo A, Dusek J, Holas O, Skoda J, Hyrsova L, Smutny T, Soukup T, Dosedel M, Pávek P. Teriflunomide Is an Indirect Human Constitutive Androstane Receptor (CAR) Activator Interacting With Epidermal Growth Factor (EGF) Signaling. Front Pharmacol 2018; 9:993. [PMID: 30364229 PMCID: PMC6193428 DOI: 10.3389/fphar.2018.00993] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 08/13/2018] [Indexed: 01/19/2023] Open
Abstract
The constitutive androstane receptor (CAR) is a nuclear receptor involved mainly in xenobiotic and endobiotic metabolism regulation. CAR is activated directly by its ligands via the ligand binding domain (LBD) or indirectly by inhibition of the epidermal growth factor (EGF) signaling. We found that leflunomide (LEF) and its main metabolite teriflunomide (TER), both used for autoimmune diseases treatment, induce the prototype CAR target gene CYP2B6 in primary human hepatocytes. As TER was discovered to be an EGF receptor antagonist, we sought to determine if TER is an indirect activator of CAR. In primary human hepatocytes and in differentiated HepaRG cells, we found that LEF and TER up-regulate CAR target genes CYP2B6 and CYP3A4 mRNAs and enzymatic activities. TER stimulated CAR+A mutant translocation into the nucleus but neither LEF nor TER activated the CAR LBD, CAR3 variant or pregnane X receptor (PXR) in gene reporter assays. Interestingly, TER significantly up-regulated CAR mRNA expression, a result which could be a consequence of both EGF receptor and ELK-1 transcription factor inhibition by TER or by TER-mediated activation of glucocorticoid receptor (GR), an upstream hormonal regulator of CAR. We can conclude that TER is a novel indirect CAR activator which through EGF inhibition and GR activation controls both detoxification and some intermediary metabolism genes.
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Affiliation(s)
- Alejandro Carazo
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Charles University, Prague, Czechia.,Faculty of Medicine and Dentistry, Institute of Molecular and Translational Medicine, Palacky University, Olomouc, Czechia
| | - Jan Dusek
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Charles University, Prague, Czechia
| | - Ondrej Holas
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Charles University, Prague, Czechia
| | - Josef Skoda
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Charles University, Prague, Czechia
| | - Lucie Hyrsova
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Charles University, Prague, Czechia
| | - Tomas Smutny
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Charles University, Prague, Czechia
| | - Tomas Soukup
- Division of Rheumatology, 2nd Department of Internal Medicine - Gastroenterology, Faculty of Medicine, University Hospital in Hradec Kralove, Charles University, Prague, Czechia
| | - Martin Dosedel
- Department of Social and Clinical Pharmacy, Faculty of Pharmacy, Charles University, Prague, Czechia
| | - Petr Pávek
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Charles University, Prague, Czechia
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Volpe DA, Xu Y, Sahajwalla CG, Younis IR, Patel V. Methadone Metabolism and Drug-Drug Interactions: In Vitro and In Vivo Literature Review. J Pharm Sci 2018; 107:2983-2991. [PMID: 30205091 DOI: 10.1016/j.xphs.2018.08.025] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 08/20/2018] [Accepted: 08/24/2018] [Indexed: 11/19/2022]
Abstract
Methadone is utilized for the treatment of individuals with opiate dependence. Methadone undergoes N-demethylation by multiple cytochrome P450 (CYP) enzymes including CYP3A4, CYP2B6, CYP2C19, CYP2D6, CYP2C9, and CYP2C8. In vivo, polymorphism effects on methadone systemic exposure have been noted for CYP2B6, CYP3A4, and CYP2D6. Clinical drug interaction studies with antiviral drugs in methadone maintenance treatment patients yield varying results on methadone pharmacokinetics and pharmacodynamics. In general, CYP inhibitors altered methadone exposure with no adverse effects. CYP inducers generally decreased methadone exposure with some reports of withdrawal symptoms in the subjects. Interaction studies with antiviral drug combinations yielding differing results depend on the enzyme(s) affected. For certain antiviral medicines which are dual inhibitor(s) and inducer(s) for CYP enzymes, their effect on methadone pharmacokinetics can change with time since the effect of induction is usually delayed compared to the effect of inhibition.
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Affiliation(s)
- Donna A Volpe
- Office of Clinical Pharmacology, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland 20993.
| | - Yun Xu
- Office of Clinical Pharmacology, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland 20993
| | - Chandrahas G Sahajwalla
- Office of Clinical Pharmacology, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland 20993
| | - Islam R Younis
- Office of Clinical Pharmacology, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland 20993
| | - Vikram Patel
- Office of Clinical Pharmacology, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland 20993
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Yoshioka K, Ohmori K, Iwasaki S, Takahashi K, Sato A, Nakata H, Miyamoto A, Yamakage M. A case of a warfarinized renal cancer patient monitored for prothrombin time-international normalized ratio during methadone introduction. JA Clin Rep 2017; 3:35. [PMID: 29457079 PMCID: PMC5804617 DOI: 10.1186/s40981-017-0092-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 04/28/2017] [Indexed: 11/29/2022] Open
Abstract
Background Warfarin, a widely used anticoagulant, interacts with various agents used in palliative care, such as oxycodone, morphine, acetaminophen, and non-steroidal anti-inflammatory drugs (NSAIDs); however, there are no reports of its interaction with methadone. We report a case of a patient receiving warfarin when methadone was introduced for pain control with monitoring of the prothrombin time-international normalized ratio (PT-INR) and deduced the pharmacological background. Case presentation A 60-year-old male was emergently admitted to our university hospital for the sudden onset of severe back pain. Abdominal CT imaging revealed that the vertebral body of the ninth thoracic vertebra was occupied by bone metastasis and crushed, which caused his back pain. He received warfarin 3.5 mg/day for atrial fibrillation and tapentadol 100 mg p.o. daily for pain relief. The prothrombin time-international normalized ratio (PT-INR) was maintained at >2.2. The patient’s history included diabetes mellitus and hypertension, but his laboratory test was unremarkable with the exception that his eGFR was 34 ml/min. Initially, a fentanyl dermal patch was used instead of tapentadol to avoid interactions with warfarin. We started concomitant administration of oxycodone and 2.4 g/day of acetaminophen while monitoring the PT-INR because acetaminophen increased the PT-INR to 2.93. A continuous intravenous infusion of oxycodone was introduced, in increments of the dose, resulting in an increase of the PT-INR to 3.41, which is required to reduce the dose of warfarin to 1.5 mg. Because of the lack of effective pain relief, methadone was introduced and the dose was gradually increased. The PT-INR was not changed and the dose of warfarin was not changed. An infusion of oxycodone and oral methadone was used to allow the patient to walk in his room, and he was later transferred to the palliative hospital. Conclusions In an oral warfarinized patient, methadone seemed to undergo different metabolism than oxycodone. When warfarin and methadone are used together, we have to consider their interaction by comparing the competitive inhibition of CYP2C9 to the induction of CYP3A4 by methadone, because CYP3A4 metabolize various drugs including oxycodone.
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Zahari Z, Lee CS, Ibrahim MA, Musa N, Mohd Yasin MA, Lee YY, Tan SC, Mohamad N, Ismail R. Relationship between ABCB1 polymorphisms and serum methadone concentration in patients undergoing methadone maintenance therapy (MMT). THE AMERICAN JOURNAL OF DRUG AND ALCOHOL ABUSE 2016; 42:587-596. [PMID: 27284701 DOI: 10.3109/00952990.2016.1172078] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Methadone is a substrate of the permeability glycoprotein (P-gp) efflux transporter, which is encoded by the ABCB1 (MDR1) gene. Large interindividual variability in serum methadone levels for therapeutic response has been reported. Genetic variations in ABCB1 gene may be responsible for the variability in observed methadone concentrations. OBJECTIVE This study investigated the associations of ABCB1 polymorphisms and serum methadone concentration over the 24-hour dosing interval in opioid-dependent patients on methadone maintenance therapy (MMT). METHODS One hundred and forty-eight male opioid-dependent patients receiving MMT were recruited. Genomic deoxyribonucleic acid (DNA) was extracted from whole blood and genotyped for ABCB1 polymorphisms [i.e. 1236C>T (dbSNP rs1128503), 2677G>T/A (dbSNP rs2032582), and 3435C>T (dbSNP rs1045642)] using the allelic discrimination real-time polymerase chain reaction (PCR). Blood samples were collected at 0, 0.5, 1, 2, 4, 8, 12, and 24 hours after the dose. Serum methadone concentrations were measured using the Methadone ELISA Kit. RESULTS Our results revealed an association of CGC/TTT diplotype (1236C>T, 2677G>T/A, and 3435C>T) with dose-adjusted serum methadone concentration over the 24-hour dosing interval. Patients with CGC/TTT diplotype had 32.9% higher dose-adjusted serum methadone concentration over the 24-hour dosing interval when compared with those without the diplotype [mean (SD) = 8.12 (0.84) and 6.11 (0.41) ng ml-1 mg-1, respectively; p = 0.033]. CONCLUSION There was an association between the CGC/TTT diplotype of ABCB1 polymorphisms and serum methadone concentration over the 24-hour dosing interval among patients on MMT. Genotyping of ABCB1 among opioid-dependent patients on MMT may help individualize and optimize methadone substitution treatment.
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Affiliation(s)
- Zalina Zahari
- a Department of Pharmacy , Hospital Universiti Sains Malaysia , Kelantan , Malaysia.,b Pharmacogenetics and Novel Therapeutics Cluster , Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia (USM) , Kelantan , Malaysia
| | - Chee Siong Lee
- c Department of Emergency Medicine , School of Medical Sciences, USM , Kelantan , Malaysia
| | - Muslih Abdulkarim Ibrahim
- b Pharmacogenetics and Novel Therapeutics Cluster , Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia (USM) , Kelantan , Malaysia.,d Department of Pharmacology and Toxicology , College of Pharmacy, Hawler Medical University , Hawler , Iraq
| | - Nurfadhlina Musa
- b Pharmacogenetics and Novel Therapeutics Cluster , Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia (USM) , Kelantan , Malaysia
| | - Mohd Azhar Mohd Yasin
- b Pharmacogenetics and Novel Therapeutics Cluster , Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia (USM) , Kelantan , Malaysia.,e Department of Psychiatry , School of Medical Sciences, USM , Kelantan , Malaysia
| | - Yeong Yeh Lee
- f School of Medical Sciences, USM , Kelantan , Malaysia
| | - Soo Choon Tan
- b Pharmacogenetics and Novel Therapeutics Cluster , Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia (USM) , Kelantan , Malaysia
| | - Nasir Mohamad
- b Pharmacogenetics and Novel Therapeutics Cluster , Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia (USM) , Kelantan , Malaysia.,g Faculty of Medicine & Health Sciences , Universiti Sultan Zainal Abidin , Terengganu , Malaysia
| | - Rusli Ismail
- b Pharmacogenetics and Novel Therapeutics Cluster , Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia (USM) , Kelantan , Malaysia.,h Centre of Excellence for Research in AIDS (CERiA) , University of Malaya , Kuala Lumpur , Malaysia
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Yang HC, Chu SK, Huang CL, Kuo HW, Wang SC, Liu SW, Ho IK, Liu YL. Genome-Wide Pharmacogenomic Study on Methadone Maintenance Treatment Identifies SNP rs17180299 and Multiple Haplotypes on CYP2B6, SPON1, and GSG1L Associated with Plasma Concentrations of Methadone R- and S-enantiomers in Heroin-Dependent Patients. PLoS Genet 2016; 12:e1005910. [PMID: 27010727 PMCID: PMC4806848 DOI: 10.1371/journal.pgen.1005910] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 02/09/2016] [Indexed: 01/25/2023] Open
Abstract
Methadone maintenance treatment (MMT) is commonly used for controlling opioid dependence, preventing withdrawal symptoms, and improving the quality of life of heroin-dependent patients. A steady-state plasma concentration of methadone enantiomers, a measure of methadone metabolism, is an index of treatment response and efficacy of MMT. Although the methadone metabolism pathway has been partially revealed, no genome-wide pharmacogenomic study has been performed to identify genetic determinants and characterize genetic mechanisms for the plasma concentrations of methadone R- and S-enantiomers. This study was the first genome-wide pharmacogenomic study to identify genes associated with the plasma concentrations of methadone R- and S-enantiomers and their respective metabolites in a methadone maintenance cohort. After data quality control was ensured, a dataset of 344 heroin-dependent patients in the Han Chinese population of Taiwan who underwent MMT was analyzed. Genome-wide single-locus and haplotype-based association tests were performed to analyze four quantitative traits: the plasma concentrations of methadone R- and S-enantiomers and their respective metabolites. A significant single nucleotide polymorphism (SNP), rs17180299 (raw p = 2.24 × 10−8), was identified, accounting for 9.541% of the variation in the plasma concentration of the methadone R-enantiomer. In addition, 17 haplotypes were identified on SPON1, GSG1L, and CYP450 genes associated with the plasma concentration of methadone S-enantiomer. These haplotypes accounted for approximately one-fourth of the variation of the overall S-methadone plasma concentration. The association between the S-methadone plasma concentration and CYP2B6, SPON1, and GSG1L were replicated in another independent study. A gene expression experiment revealed that CYP2B6, SPON1, and GSG1L can be activated concomitantly through a constitutive androstane receptor (CAR) activation pathway. In conclusion, this study revealed new genes associated with the plasma concentration of methadone, providing insight into the genetic foundation of methadone metabolism. The results can be applied to predict treatment responses and methadone-related deaths for individualized MMTs. Methadone maintenance treatment (MMT), among the most effective therapies for heroin-dependent patients, reduces craving and withdrawal symptoms, increases treatment compliance, and improves the quality of life of patients. The plasma concentration of methadone is a primary index for quantifying and determining therapy responses to MMT. This study was the first whole-genome pharmacogenomic study on MMT to locate genomic regions associated with the plasma concentration of methadone. The analysis identified a single nucleotide polymorphism (SNP) marker (rs17180299) and 17 haplotypes on the SPON1, GSG1L, and CYP450 genes, including CYP2B6 significantly associated with the plasma concentrations of methadone enantiomers. The identified genetic variations accounted for approximately 10% and 25% of the variations in plasma concentrations of methadone R- and S-enantiomers, respectively. The identified genetic variations have afforded insight into the genetic mechanism of the metabolism of MMT, and have potential to pave the way towards individualized MMTs for heroin-dependent patients.
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Affiliation(s)
- Hsin-Chou Yang
- Institute of Statistical Science, Academia Sinica, Taipei, Taiwan
- Bioinformatics Program, Taiwan International Graduate Program, Institute of Information Science, Academia Sinica, Taipei, Taiwan
- Institute of Public Health, National Yang Ming University, Taipei, Taiwan
- Department of Statistics, National Cheng-Kung University, Tainan, Taiwan
- School of Public Health, National Defense Medical Center, Taipei, Taiwan
| | - Shih-Kai Chu
- Institute of Statistical Science, Academia Sinica, Taipei, Taiwan
- Bioinformatics Program, Taiwan International Graduate Program, Institute of Information Science, Academia Sinica, Taipei, Taiwan
- Institute of Biomedical Informatics, National Yang-Ming University, Taipei, Taiwan
| | - Chieh-Liang Huang
- Center for Drug Abuse and Addiction, China Medical University Hospital, Taichung, Taiwan
- School of Medicine, China Medical University, Taichung, Taiwan
| | - Hsiang-Wei Kuo
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli County, Taiwan
| | - Sheng-Chang Wang
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli County, Taiwan
| | - Sheng-Wen Liu
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli County, Taiwan
| | - Ing-Kang Ho
- Center for Drug Abuse and Addiction, China Medical University Hospital, Taichung, Taiwan
| | - Yu-Li Liu
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli County, Taiwan
- Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan
- * E-mail:
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Cottrell ML, Hadzic T, Kashuba ADM. Clinical pharmacokinetic, pharmacodynamic and drug-interaction profile of the integrase inhibitor dolutegravir. Clin Pharmacokinet 2014; 52:981-94. [PMID: 23824675 DOI: 10.1007/s40262-013-0093-2] [Citation(s) in RCA: 180] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Dolutegravir is a second-generation integrase strand transfer inhibitor (INSTI) currently under review by the US Food and Drug Administration for marketing approval. The in vitro, protein-adjusted 90 % inhibitory concentration (IC90) of dolutegravir for wild-type virus is 0.064 μg/ml, and it retains in vitro anti-HIV 1 activity across a broad range of viral phenotypes that are known to confer resistance to the currently marketed INSTIs, raltegravir and elvitegravir. Dolutegravir has a terminal elimination half-life of 13-14 h and maintains concentrations over the in vitro, protein-adjusted IC90 for more than 30 h following a single dose. Additionally, dolutegravir has low inter-subject variability compared with raltegravir and elvitegravir. A plasma exposure-response relationship has been well described, with antiviral activity strongly correlating with trough concentrations. Phase III trials have assessed the antiviral activity of dolutegravir compared with efavirenz and raltegravir in antiretroviral (ARV)-naive patients and found that dolutegravir achieved more rapid and sustained virologic suppression in both instances. Additionally, studies of dolutegravir activity in patients with known INSTI-resistant mutations have been favourable, indicating that dolutegravir retains activity in a variety of INSTI-resistant phenotypes. Much like currently marketed INSTIs, dolutegravir is very well tolerated. Because dolutegravir inhibits the renal transporter organic cation transporter 2, reduced tubular secretion of creatinine leads to non-progressive increases in serum creatinine. These serum creatinine increases have not been associated with a decreased glomerular filtration rate or progressive renal impairment. Dolutegravir's major and minor metabolic pathways are uridine diphosphate glucuronosyltransferase 1A1 and cytochrome P450 (CYP)-3A4, respectively, and it neither induces nor inhibits CYP isoenzymes. Thus dolutegravir has a modest drug interaction profile. However, antacids significantly decrease dolutegravir plasma exposure and should be separated by 2 h before, or 6 h after, a dolutegravir dose. In summary, dolutegravir is the first of the second-generation INSTIs and exhibits a predictable pharmacokinetic profile and a well-defined exposure-response relationship. Dolutegravir retains activity despite the presence of some class-resistant mutations and achieves rapid and sustained virologic suppression in ARV-naive and ARV-experienced patients. Clinically, dolutegravir is poised to become a commonly used component of antiretroviral regimens.
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Affiliation(s)
- Mackenzie L Cottrell
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, 3318 Kerr Hall, CB# 7569, Chapel Hill, NC, 27599-7569, USA
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Levran O, Peles E, Hamon S, Randesi M, Adelson M, Kreek MJ. CYP2B6 SNPs are associated with methadone dose required for effective treatment of opioid addiction. Addict Biol 2013; 18:709-16. [PMID: 21790905 DOI: 10.1111/j.1369-1600.2011.00349.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Adequate methadone dosing in methadone maintenance treatment (MMT) for opioid addiction is critical for therapeutic success. One of the challenges in dose determination is the inter-individual variability in dose-response. Methadone metabolism is attributed primarily to cytochrome P450 enzymes CYP3A4, CYP2B6 and CYP2D6. The CYP2B6*6 allele [single nucleotide polymorphisms (SNPs) 785A>G (rs2279343) and 516G>T (rs3745274)] was associated with slow methadone metabolism. To explore the effects of CYP2B6*6 allele on methadone dose requirement, it was genotyped in a well-characterized sample of 74 Israeli former heroin addicts in MMT. The sample is primarily of Middle Eastern/European ancestry, based on ancestry informative markers (AIMs). Only patients with no major co-medication that may affect methadone metabolism were included. The stabilizing daily methadone dose in this sample ranges between 13 and 260mg (mean 140±52mg). The mean methadone doses required by subjects homozygous for the variant alleles of the CYP2B6 SNPs 785A>G and 516G>T (88, 96mg, respectively) were significantly lower than those of the heterozygotes (133, 129mg, respectively) and the non-carriers (150, 151mg, respectively) (nominal P=0.012, 0.048, respectively). The results remain significant after controlling for age, sex and the ABCB1 SNP 1236C>T (rs1128503), which was previously shown to be associated with high methadone dose requirement in this population (P=0.006, 0.030, respectively). An additional 77 CYP2B6, CYP3A4 and CYP2D6 SNPs were genotyped. Of these, 24 SNPs were polymorphic and none showed significant association with methadone dose. Further studies are necessary to replicate these preliminary findings in additional subjects and other populations.
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Affiliation(s)
- Orna Levran
- Laboratory of the Biology of Addictive Diseases, The Rockefeller University, New York, NY 10065, USA.
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Abstract
BACKGROUND There is considerable interindividual and intraindividual variability in methadone metabolism and clearance. Methadone dosing is particularly challenging during initiation of therapy, because of time-dependent increases in hepatic clearance (autoinduction). Although methadone N-demethylation is catalyzed in vitro by cytochrome P4502B6 (CYP2B6) and CYP3A4, and clearance in vivo depends on CYP2B6, mechanism(s) of autoinduction are incompletely understood. In this investigation, we determined mechanism(s) of methadone autoinduction using human hepatocytes. METHODS Fresh human hepatocytes were exposed to 0.1 to 10 µM methadone for 72 hours. Cells were washed and methadone N-demethylation assessed. CYP2B6, CYP3A4, and CYP3A5 messenger RNA (mRNA), protein expression (by gel-free high-performance liquid chromatography mass spectrometry) and catalytic activity (bupropion hydroxylation and alfentanil dealkylation for CYP2B6 and CYP3A4/5, respectively) were measured. Mechanisms of CYP induction were characterized using pregnane X receptor and constitutive androstane receptor reporter gene assays. RESULTS Methadone (10 µM) increased methadone N-demethylation 2-fold, CYP2B6 and CYP3A4 mRNA 3-fold, and protein expression 2-fold. CYP3A5 mRNA was unchanged. CYP2B6 and CYP3A4/5 activities increased 2-fold. Induction by methadone enantiomers (R-methadone versus S-methadone) did not differ. Induction was relatively weak compared with maximum induction by phenobarbital and rifampin. Lower methadone concentrations had smaller effects. Methadone was an agonist for the pregnane X receptor but not the constitutive androstane receptor. CONCLUSIONS Methadone caused concentration-dependent autoinduction of methadone N-demethylation in human hepatocytes, related to induction of CYP2B6 and CYP3A4 mRNA expression, protein expression, and catalytic activity. Induction was related to pregnane X receptor but not constitutive androstane receptor activation. These in vitro findings provide mechanistic insights into clinical autoinduction of methadone metabolism and clearance.
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Latuga NM, Wahler RG. Very-High-Dose Methadone With Minimal Toxicity and Inadequate Pain Control in a Hospice Patient With Cancer. J Pain Palliat Care Pharmacother 2013; 27:143-9. [DOI: 10.3109/15360288.2013.786011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Hassan HE, Myers AL, Lee IJ, Mason CW, Wang D, Sinz MW, Wang H, Eddington ND. Induction of Xenobiotic Receptors, Transporters, and Drug Metabolizing Enzymes by Oxycodone. Drug Metab Dispos 2013; 41:1060-9. [DOI: 10.1124/dmd.112.050401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Bogen DL, Perel JM, Helsel JC, Hanusa BH, Romkes M, Nukui T, Friedman CR, Wisner KL. Pharmacologic evidence to support clinical decision making for peripartum methadone treatment. Psychopharmacology (Berl) 2013; 225:441-51. [PMID: 22926004 PMCID: PMC3537905 DOI: 10.1007/s00213-012-2833-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2012] [Accepted: 07/26/2012] [Indexed: 11/24/2022]
Abstract
RATIONALE Limited pharmacological data are available to guide methadone treatment during pregnancy and postpartum. OBJECTIVES Study goals were to (1) characterize changes in methadone dose across childbearing, (2) determine enantiomer-specific methadone withdrawal kinetics from steady state during late pregnancy, (3) assess enantiomer-specific changes in methadone level/dose (L/D) ratios across childbearing, and (4) explore relationships between CYP2B6, CYP2C19, and CYP3A4 single-nucleotide polymorphisms and maternal dose, plasma concentration, and L/D. METHODS Methadone dose changes and timed plasma samples were obtained for women on methadone (n = 25) followed prospectively from third trimester of pregnancy to 3 months postpartum. RESULTS Participants were primarily white, Medicaid insured, and multiparous. All women increased their dose from first to end of second trimester (mean peak increase = 23 mg/day); 71 % of women increased from second trimester to delivery (mean peak increase = 19 mg/day). Half took a higher dose 3 months postpartum than at delivery despite significantly larger clearance during late pregnancy. Third trimester enantiomer-specific methadone half-lives (range R-methadone 14.7-24.9 h; S-methadone, 8.02-18.9 h) were about half of those reported in non-pregnant populations. In three women with weekly 24-h methadone levels after delivery, L/D increased within 1-2 weeks after delivery. Women with the CYP2B6 Q172 variant GT genotype have consistently higher L/D values for S-methadone across both pregnancy and postpartum. CONCLUSIONS Most women require increases in methadone dose across pregnancy. Given the shorter half-life and larger clearances during pregnancy, many pregnant women may benefit from split methadone dosing. L/D increases quickly after delivery and doses should be lowered rapidly after delivery.
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Affiliation(s)
- D. L. Bogen
- Department of Pediatrics, Division of General Academic Pediatrics, Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA
,Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - J. M. Perel
- Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, PA
,Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA
| | - J. C. Helsel
- Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, PA
,Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA
| | - B. H. Hanusa
- Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - M. Romkes
- Center for Clinical Pharmacology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - T. Nukui
- Center for Clinical Pharmacology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - C. R. Friedman
- Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - K. L. Wisner
- Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, PA
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Inhibition of cytochrome P450 3A in rat liver by the Diorganotin (IV) compound di-n-Butyl-di-(4-chlorobenzo-hydroxamato)tin (IV) and Its Probable Mechanism. Molecules 2012; 17:10994-1009. [PMID: 22971584 PMCID: PMC6268477 DOI: 10.3390/molecules170910994] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 08/28/2012] [Accepted: 09/03/2012] [Indexed: 11/25/2022] Open
Abstract
The specific aims of this study were to evaluate the inhibition effect on CYP3A of di-n-butyl-di-(4-chlorobenzohydroxamato)tin (IV) (DBDCT), a tin-based complex with high antitumor activity, and the probable mechanism(s) of this action. Adult male SD rats were treated separately with natural saline (NS), lipopolysaccharide (LPS, 5 mg/kg), DBDCT (1.25, 2.5 and 5.0 mg/kg) intraperitoneally for 2 days after induction of CYP3A with dexamethasone (DEX, 100 mg/kg) for 4 days. Western blot analysis and fluorescent quantitation PCR (FQ-PCR) were conducted to determine the changes in expression of CYP3A, PXR, CAR and RXR. The biological accumulation of DBDCT and total Sn were determined by high-performance liquid chromatography (HPLC) and atomic fluorescence spectrometry (AFS). CYP450 content and CYP3A activities were significantly inhibited (p < 0.05) in DBDCT-treated rats compared with the control group, as was the expression of CYP3A (p < 0.05) at both protein and mRNA levels. In DBDCT-treated groups, the expression of PXR protein and mRNA increased, while the expression of CAR decreased. The biological accumulation of DBDCT and Sn in rat livers treated with DBDCT was high. The accumulation of DBDCT and Sn due to the inhibition of CYP3A may be involved in the mechanism of toxicity of DBDCT in rat liver.
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Wang D, Wang H. Oxazaphosphorine bioactivation and detoxification The role of xenobiotic receptors. Acta Pharm Sin B 2012; 2. [PMID: 24349963 DOI: 10.1016/j.apsb.2012.02.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Oxazaphosphorines, with the most representative members including cyclophosphamide, ifosfamide, and trofosfamide, constitute a class of alkylating agents that have a broad spectrum of anticancer activity against many malignant ailments including both solid tumors such as breast cancer and hematological malignancies such as leukemia and lymphoma. Most oxazaphosphorines are prodrugs that require hepatic cytochrome P450 enzymes to generate active alkylating moieties before manifesting their chemotherapeutic effects. Meanwhile, oxazaphosphorines can also be transformed into non-therapeutic byproducts by various drug-metabolizing enzymes. Clinically, oxazaphosphorines are often administered in combination with other chemotherapeutics in adjuvant treatments. As such, the therapeutic efficacy, off-target toxicity, and unintentional drug-drug interactions of oxazaphosphorines have been long-lasting clinical concerns and heightened focuses of scientific literatures. Recent evidence suggests that xenobiotic receptors may play important roles in regulating the metabolism and clearance of oxazaphosphorines. Drugs as modulators of xenobiotic receptors can affect the therapeutic efficacy, cytotoxicity, and pharmacokinetics of coadministered oxazaphosphorines, providing a new molecular mechanism of drug-drug interactions. Here, we review current advances regarding the influence of xenobiotic receptors, particularly, the constitutive androstane receptor, the pregnane X receptor and the aryl hydrocarbon receptor, on the bioactivation and detoxification of oxazaphosphorines, with a focus on cyclophosphamide and ifosfamide.
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Yanakakis LJ, Bumpus NN. Biotransformation of the antiretroviral drug etravirine: metabolite identification, reaction phenotyping, and characterization of autoinduction of cytochrome P450-dependent metabolism. Drug Metab Dispos 2012; 40:803-14. [PMID: 22269145 DOI: 10.1124/dmd.111.044404] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Etravirine (ETR) is a second-generation non-nucleoside reverse transcriptase inhibitor prescribed for the treatment of HIV-1. By using human liver microsomes (HLMs), cDNA-expressed cytochromes P450 (P450s), and UDP-glucuronosyltransferases (UGTs), the routes of ETR metabolism were defined. Incubations with cDNA-expressed P450 isozymes and chemical inhibition studies using HLMs indicated that CYP2C19 is primarily responsible for the formation of both the major monohydroxylated and dihydroxylated metabolites of ETR. Tandem mass spectrometry suggested that these metabolites were produced via monomethylhydroxylation and dimethylhydroxylation of the dimethylbenzonitrile moiety. Formation of these monohydroxy and dihydroxy metabolites was decreased by 75 and 100%, respectively, in assays performed using HLMs that were genotyped as homozygous for the loss-of-function CYP2C19*2 allele compared with formation by HLMs genotyped as CYP2C19*1/*1. Two monohydroxylated metabolites of lower abundance were formed by CYP3A4, and interestingly, although CYP2C9 showed no activity toward the parent compound, this enzyme appeared to act in concert with CYP3A4 to form two minor dihydroxylated products of ETR. UGT1A3 and UGT1A8 were demonstrated to glucuronidate a CYP3A4-dependent monohydroxylated product. In addition, treatment of primary human hepatocytes with ETR resulted in 3.2-, 5.2-, 11.8-, and 17.9-fold increases in CYP3A4 mRNA levels 6, 12, 24, and 72 h after treatment. The presence of the pregnane X receptor antagonist sulforaphane blocked the ETR-mediated increase in CYP3A4 mRNA expression. Taken together, these data suggest that ETR and ETR metabolites are substrates of CYP2C19, CYP3A4, CYP2C9, UGT1A3, and UGT1A8 and that ETR is a PXR-dependent modulator of CYP3A4 mRNA levels.
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Pan Y, Li L, Kim G, Ekins S, Wang H, Swaan PW. Identification and validation of novel human pregnane X receptor activators among prescribed drugs via ligand-based virtual screening. Drug Metab Dispos 2010; 39:337-44. [PMID: 21068194 DOI: 10.1124/dmd.110.035808] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Human pregnane X receptor (hPXR) plays a key role in regulating metabolism and clearance of endogenous and exogenous substances. Identification of novel hPXR activators among commercial drugs may aid in avoiding drug-drug interactions during coadministration. We applied ligand-based computational approaches for virtual screening of a commonly prescribed drug database (SCUT). Bayesian classification models were generated with a training set comprising 177 compounds using Fingerprints and 117 structural descriptors. A cell-based luciferase reporter assay was used for evaluation of chemical-mediated hPXR activation in HepG2 cells. All compounds were tested at 10 μM concentration with rifampicin and dimethyl sulfoxide as positive and negative controls, respectively. The Bayesian models showed specificity and overall prediction accuracy up to 0.92 and 0.69 for test set compounds. Screening the SCUT database with this model retrieved 105 hits and 17 compounds from the top 25 hits were chosen for in vitro testing. The reporter assay confirmed that nine drugs, i.e., fluticasone, nimodipine, nisoldipine, beclomethasone, finasteride, flunisolide, megestrol, secobarbital, and aminoglutethimide, were previously unidentified hPXR activators. Thus, the present study demonstrates that novel hPXR activators can be efficiently identified among U.S. Food and Drug Administration-approved and commonly prescribed drugs, which should lead to detection and prevention of potential drug-drug interactions.
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Affiliation(s)
- Yongmei Pan
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 Penn St., HSF2-621, Baltimore, MD 21201, USA
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Regulation of drug-metabolizing enzymes by xenobiotic receptors: PXR and CAR. Adv Drug Deliv Rev 2010; 62:1238-49. [PMID: 20727377 DOI: 10.1016/j.addr.2010.08.006] [Citation(s) in RCA: 272] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 08/09/2010] [Accepted: 08/10/2010] [Indexed: 12/24/2022]
Abstract
Drug-metabolizing enzymes (DMEs) and transporters play pivotal roles in the disposition and detoxification of numerous foreign and endogenous chemicals. To accommodate chemical challenges, the expression of many DMEs and transporters is up-regulated by a group of ligand-activated transcription factors namely nuclear receptors (NRs). The importance of NRs in xenobiotic metabolism and clearance is best exemplified by the most promiscuous xenobiotic receptors: pregnane X receptor (PXR, NR1I2) and constitutive androstane/activated receptor (CAR, NR1I3). Together, these two receptors govern the inductive expression of a largely overlapping array of target genes encoding phase I and II DMEs, and drug transporters. Moreover, PXR and CAR also represent two distinctive mechanisms of NR activation, whereby CAR demonstrates both constitutive and ligand-independent activation. In this review, recent advances in our understanding of PXR and CAR as xenosensors are discussed with emphasis placed on the differences rather than similarities of these two xenobiotic receptors in ligand recognition and target gene regulation.
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Li Y, Wang Q, Yao X, Li Y. Induction of CYP3A4 and MDR1 gene expression by baicalin, baicalein, chlorogenic acid, and ginsenoside Rf through constitutive androstane receptor- and pregnane X receptor-mediated pathways. Eur J Pharmacol 2010; 640:46-54. [PMID: 20580705 DOI: 10.1016/j.ejphar.2010.05.017] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Revised: 03/24/2010] [Accepted: 05/06/2010] [Indexed: 02/07/2023]
Abstract
The herbal products baicalin, baicalein, chlorogenic acid, and ginsenoside Rf have multiple pharmacological effects and are extensively used in alternative and/or complementary therapies. The present study investigated whether baicalin, baicalein, chlorogenic acid, and ginsenoside Rf induced the expression of the cytochrome P450 3A4 (CYP3A4) and multi-drug resistance 1 (MDR1) genes through the pregnane X receptor and constitutive androstane receptor pathways. Real time PCR, western blotting, and a luminescent assay were used to assess the induction of gene expression and activity of CYP3A4 and MDR1 by the test compounds. The interactions of baicalein/chlorogenic acid/ginsenoside Rf with constitutive androstane receptor and pregnane X receptor were evaluated using luciferase reporter and gel shift assays. Baicalein induced the expression of CYP3A4 and MDR1 mRNA by activating pregnane X receptor and constitutive androstane receptor. Chlorogenic acid and ginsenoside Rf showed a relatively weak effect on CYP3A4 promoter activation only in HepG2 cells cotransfected with constitutive androstane receptor and demonstrated no effects on MDR1 via either the constitutive androstane receptor or pregnane X receptor pathway. Baicalin had no effect on either CYP3A4 or MDR1 gene expression. In conclusion, baicalein has the potential to up-regulate CYP3A4 and MDR1 through the direct activation of the constitutive androstane receptor and pregnane X receptor pathways. Chlorogenic acid and ginsenoside Rf only induced constitutive androstane receptor-mediated CYP3A4 expression.
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Affiliation(s)
- Yue Li
- Department of New Drug Development, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, and Institute of Infectious Diseases, Beijing Ditan Hospital, No. 1, Xian Nong Tan Street, Beijing 100050, China.
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Li L, Hassan HE, Tolson AH, Ferguson SS, Eddington ND, Wang H. Differential activation of pregnane X receptor and constitutive androstane receptor by buprenorphine in primary human hepatocytes and HepG2 cells. J Pharmacol Exp Ther 2010; 335:562-71. [PMID: 20829393 DOI: 10.1124/jpet.110.173187] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Buprenorphine is a partial μ-opioid receptor agonist used for the treatment of opioid dependence that has several advantages over methadone. The principal route of buprenorphine disposition has been well established; however, little is known regarding the potential for buprenorphine to influence the metabolism and clearance of other drugs by affecting the expression of drug-metabolizing enzymes (DMEs). Here, we investigate the effects of buprenorphine on the activation of pregnane X receptor (PXR) and constitutive androstane receptor (CAR), as well as the induction of DMEs, in both HepG2 cells and human primary hepatocytes (HPHs). In HepG2 cells, buprenorphine significantly increased human PXR-mediated CYP2B6 and CYP3A4 reporter activities. CYP2B6 reporter activity was also enhanced by buprenorphine in HepG2 cells cotransfected with a chemical-responsive human CAR variant. Real-time reverse transcription-polymerase chain reaction analysis revealed that buprenorphine strongly induced CYP3A4 expression in both PXR- and CAR-transfected HepG2 cells. However, treatment with the same concentrations of buprenorphine in HPHs resulted in literally no induction of CYP3A4 or CYP2B6 expression. Further studies indicated that buprenorphine could neither translocate human CAR to the nucleus nor activate CYP2B6/CYP3A4 reporter activities in transfected HPHs. Subsequent experiments to determine whether the differential response was due to buprenorphine's metabolic stability revealed a dramatically differential rate of elimination for buprenorphine between HPHs and HepG2 cells. Taken together, these studies indicate that metabolic stability of buprenorphine defines the differential induction of DMEs observed in HepG2 and HPHs, and the results obtained from PXR and CAR reporter assays in immortalized cell line require cautious interpretation.
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Affiliation(s)
- Linhao Li
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, USA
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French D, Stone JA, Chang JS, Wu AH. Choosing the Right Benzodiazepine Assay: Impact on Clinical Decision Making. Lab Med 2010. [DOI: 10.1309/lmdnlg1zvos2r8tv] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Chen T, Tompkins LM, Li L, Li H, Kim G, Zheng Y, Wang H. A single amino acid controls the functional switch of human constitutive androstane receptor (CAR) 1 to the xenobiotic-sensitive splicing variant CAR3. J Pharmacol Exp Ther 2009; 332:106-15. [PMID: 19820207 DOI: 10.1124/jpet.109.159210] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The constitutive androstane receptor (CAR) is constitutively activated in immortalized cell lines independent of xenobiotic stimuli. This feature of CAR has limited its use as a sensor for xenobiotic-induced expression of drug-metabolizing enzymes. Recent reports, however, reveal that a splicing variant of human CAR (hCAR3), which contains an insertion of five amino acids (APYLT), exhibits low basal but xenobiotic-inducible activities in cell-based reporter assays. Nonetheless, the underlying mechanisms of this functional shift are not well understood. We have now generated chimeric constructs containing various residues of the five amino acids of hCAR3 and examined their response to typical hCAR activators. Our results showed that the retention of alanine (hCAR1+A) alone is sufficient to confer the constitutively activated hCAR1 to the xenobiotic-sensitive hCAR3. It is noteworthy that hCAR1+A was significantly activated by a series of known hCAR activators, and displayed activation superior to that of hCAR3. Moreover, intracellular localization assays revealed that hCAR1+A exhibits nuclear accumulation upon 6-(4-chlorophenyl) imidazo[2,1-b][1,3]thiazole-5-carbaldehyde-O-(3,4-dichlorobenzyl) oxime (CITCO) treatment in COS1 cells, which differs from the spontaneous nuclear distribution of hCAR1 and the nontranslocatable hCAR3. Mammalian two-hybrid and glutathione S-transferase pull-down assays further demonstrated that hCAR1+A interacts with the coactivator SRC-1 and GRIP-1 at low level before activation, while at significantly enhanced level in the presence of CITCO. Thus, the alanine residue in the insertion of hCAR3 seems in charge of the xenobiotic response of hCAR3 through direct and indirect mechanisms. Activation of hCAR1+A may represent a sensitive avenue for the identification of hCAR activators.
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Affiliation(s)
- Tao Chen
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, USA
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