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Albitar O, Harun SN, Sheikh Ghadzi SM. Semi-physiological Pharmacokinetic Model of Clozapine and Norclozapine in Healthy, Non-smoking Volunteers: The Impact of Race and Genetics. CNS Drugs 2024:10.1007/s40263-024-01092-1. [PMID: 38836990 DOI: 10.1007/s40263-024-01092-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/17/2024] [Indexed: 06/06/2024]
Abstract
BACKGROUND AND OBJECTIVES: Clozapine is the medication of choice for treatment-resistant schizophrenia. However, it has a complex metabolism and unexplained interindividual variability. The current work aims to develop a pharmacokinetic model of clozapine and norclozapine in non-smokers and assess the impact of demographic and genetic predictors. METHODS Healthy volunteers were recruited in a population pharmacokinetic study. Blood samples were collected at 30 min and 1, 2, 3, 5 and 8 h following a single flat dose of clozapine (12.5 mg). The clozapine and norclozapine concentrations were measured via high-performance liquid chromatography-ultraviolet method. A semi-physiological pharmacokinetic model of clozapine and norclozapine was developed using nonlinear mixed-effects modeling. Clinical and genetic predictors were evaluated, including CYP1A2 (rs762551) and ABCB1 (rs2032582), using restriction fragment length polymorphism. RESULTS A total of 270 samples were collected from 33 participants. The data were best described using a two-compartment model for clozapine and a two-compartment model for norclozapine with first-order absorption and elimination and pre-systemic metabolism. The estimated (relative standard error) clearance of clozapine and norclozapine were 27 L h-1 (31.5 %) and 19.6 L h-1 (30%), respectively. Clozapine clearance was lower in sub-Saharan Africans (n = 4) and higher in Caucasians (n = 9) than Asians (n = 20). Participants with CYP1A2 (rs762551) (n = 18) and ABCB1 (rs2032582) (n = 12) mutant alleles had lower clozapine clearance in the univariate analysis. CONCLUSIONS This is the first study to develop a semi-physiological pharmacokinetic model of clozapine and norclozapine accounting for the pre-systemic metabolism. Asians required lower doses of clozapine as compared with Caucasians, while clozapine pharmacokinetics in sub-Saharan Africans should be further investigated in larger trials.
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Affiliation(s)
- Orwa Albitar
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, USM, 11800, Gelugor, Penang, Malaysia
- Roche Pharma Research and Early Development, Basel, Switzerland
| | - Sabariah Noor Harun
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, USM, 11800, Gelugor, Penang, Malaysia
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2
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Tremmel R, Hofmann U, Haag M, Schaeffeler E, Schwab M. Circulating Biomarkers Instead of Genotyping to Establish Metabolizer Phenotypes. Annu Rev Pharmacol Toxicol 2024; 64:65-87. [PMID: 37585662 DOI: 10.1146/annurev-pharmtox-032023-121106] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/18/2023]
Abstract
Pharmacogenomics (PGx) enables personalized treatment for the prediction of drug response and to avoid adverse drug reactions. Currently, PGx mainly relies on the genetic information of absorption, distribution, metabolism, and excretion (ADME) targets such as drug-metabolizing enzymes or transporters to predict differences in the patient's phenotype. However, there is evidence that the phenotype-genotype concordance is limited. Thus, we discuss different phenotyping strategies using exogenous xenobiotics (e.g., drug cocktails) or endogenous compounds for phenotype prediction. In particular, minimally invasive approaches focusing on liquid biopsies offer great potential to preemptively determine metabolic and transport capacities. Early studies indicate that ADME phenotyping using exosomes released from the liver is reliable. In addition, pharmacometric modeling and artificial intelligence improve phenotype prediction. However, further prospective studies are needed to demonstrate the clinical utility of individualized treatment based on phenotyping strategies, not only relying on genetics. The present review summarizes current knowledge and limitations.
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Affiliation(s)
- Roman Tremmel
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany;
- University of Tuebingen, Tuebingen, Germany
| | - Ute Hofmann
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany;
- University of Tuebingen, Tuebingen, Germany
| | - Mathias Haag
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany;
- University of Tuebingen, Tuebingen, Germany
| | - Elke Schaeffeler
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany;
- University of Tuebingen, Tuebingen, Germany
- Cluster of Excellence iFIT (EXC2180) "Image-Guided and Functionally Instructed Tumor Therapies," University of Tuebingen, Tuebingen, Germany
| | - Matthias Schwab
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany;
- University of Tuebingen, Tuebingen, Germany
- Cluster of Excellence iFIT (EXC2180) "Image-Guided and Functionally Instructed Tumor Therapies," University of Tuebingen, Tuebingen, Germany
- Departments of Clinical Pharmacology, and Pharmacy and Biochemistry, University of Tuebingen, Tuebingen, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center Heidelberg (DKFZ), Partner Site, Tübingen, Germany
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3
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Alsultan A, Alalwan AA, Alshehri B, Jeraisy MA, Alghamdi J, Alqahtani S, Albassam AA. Interethnic differences in drug response: projected impact of genetic variations in the Saudi population. Pharmacogenomics 2023; 24:685-696. [PMID: 37610881 DOI: 10.2217/pgs-2023-0105] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/25/2023] Open
Abstract
Ethnicity is known to have an impact on drug responses. This is particularly important for drugs that have a narrow therapeutic window, nonlinearity in pharmacokinetics and are metabolized by enzymes that demonstrate genetic polymorphisms. However, most clinical trials are conducted among Caucasians, which might limit the usefulness of the findings of such studies for other ethnicities. The representation of participants from Saudi Arabia in global clinical trials is low. Therefore, there is a paucity of evidence to assess the impact of ethnic variability in the Saudi population on drug response. In this article, the authors assess the projected impact of genetic polymorphisms in drug-metabolizing enzymes and drug targets on drug response in the Saudi population.
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Affiliation(s)
- Abdullah Alsultan
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Abdullah A Alalwan
- Department of Clinical Pharmacy, College of Pharmacy, Prince Sattam bin Abdulaziz University, Al-Kharj, Saudi Arabia
| | - Bashayer Alshehri
- Pharmaceutical Care Department, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - Majed Al Jeraisy
- Pharmaceutical Care Department, King Abdulaziz Medical City, Riyadh, Saudi Arabia
- College of Pharmacy, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
- King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
| | - Jahad Alghamdi
- Saudi Food and Drug Authority, Drug Sector, Riyadh, Saudi Arabia
| | - Saeed Alqahtani
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Ahmed A Albassam
- Department of Clinical Pharmacy, College of Pharmacy, Prince Sattam bin Abdulaziz University, Al-Kharj, Saudi Arabia
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4
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Collins JM, Lester H, Shabnaz S, Wang D. A frequent CYP2D6 variant promotes skipping of exon 3 and reduces CYP2D6 protein expression in human liver samples. Front Pharmacol 2023; 14:1186540. [PMID: 37576811 PMCID: PMC10412816 DOI: 10.3389/fphar.2023.1186540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 07/17/2023] [Indexed: 08/15/2023] Open
Abstract
CYP2D6 is one of the most polymorphic drug-metabolizing enzymes in the liver. While genetic CYP2D6 variants serve as clinical biomarkers to predict CYP2D6 activity, large inter-person variability in CYP2D6 expression remains unaccounted for. Previous results suggest that there is variable expression of a CYP2D6 splice isoform with an in-frame deletion of exon 3 (CYP2D6ΔE3) encoding a protein lacking numerous active site residues. Here, using fragment analysis and RT-qPCR, we revealed that rs1058164 G (MAF = 27%-43%) is associated with increased formation of CYP2D6∆E3 in human liver samples (1.4-2.5-fold) and transfected cells. Furthermore, western blots showed that rs1058164 G was associated with a 50% decrease in full-length hepatic CYP2D6 protein expression. In addition, by studying a larger liver cohort, we confirmed our previous results that rs16947 (CYP2D6*2) reduces full-length CYP2D6 mRNA by increasing the production of an unstable splice isoform lacking exon 6 (CYP2D6ΔE6) and that the impact of CYP2D6ΔE6 is offset in carriers of the downstream enhancer variant rs5758550. The three frequent SNPs (rs1058164, rs16947, and rs5758550) form various 3-SNP-haplotypes, each with distinct CYP2D6 expression characteristics. Using an expression score (ES) system, we tested the impact of the 3-SNP-haplotype on improving the standard model to predict hepatic CYP2D6 protein expression based on genotype. A model that incorporates the 3-SNP-haplotype provided the best fit for CYP2D6 expression and also accounted for more variability in CYP2D6 protein levels (59%) than a model based on the accepted standard (36%) or one that only adds rs16947 and rs5758550 (42%). Clinical studies are needed to determine whether including the 3-SNP-haplotype alongside current standard CYP2D6 models improves the predictive value of CYP2D6 panels.
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Affiliation(s)
| | | | | | - Danxin Wang
- Department of Pharmacotherapy and Translational Research, Center for Pharmacogenomics, College of Pharmacy, University of Florida, Gainesville, FL, United States
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Wang Z, Li QQ, Huang CK, Dong YY, Lang LP, Sun W, Qian JC, Zhang XD. Determination of CYP450 activities in diabetes mellitus rats by a UHPLC-MS/MS method. J Pharm Biomed Anal 2023; 224:115191. [PMID: 36512868 DOI: 10.1016/j.jpba.2022.115191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/08/2022] [Accepted: 11/27/2022] [Indexed: 11/30/2022]
Abstract
In this study, we investigated the effect of type 1 diabetes mellitus on the modulation of the activities of CYP450s in dynamics by a UHPLC-MS/MS method. The diabetic rat model was constructed by an intraperitoneal single injection of streptozotocin. Fasting blood glucose levels > 16.7 mmol/L were considered as diabetic. The rats were given a cocktail of four probe drugs (10 mg/kg phenacetin, 1 mg/kg tolbutamide, 10 mg/kg metoprolol, and 10 mg/kg midazolam) by oral administration for the pharmacokinetic study. Thereafter, the metabolic ratio (MR) of the metabolites to probe substrates were determined. The results indicated that two weeks after diabetes was induced, diabetes increased the MRs of acetaminophen/phenacetin (CYP1A2) and 4-hydroxyl tolbutamide/tolbutamide (CYP2C9); however, it decreased the MRs of α-hydroxy metoprolol/metoprolol (CYP2D6) and 1-hydroxy midazolam/midazolam (CYP3A4). Two months after diabetes was induced, diabetes increased the MRs of acetaminophen/phenacetin and 4-hydroxyl tolbutamide/tolbutamide. The MR of α-hydroxy metoprolol/metoprolol was decreased and the MR of 1-hydroxy midazolam/midazolam was increased but the difference was not significant. According to the results, CYP1A2 and CYP2C9 activities were enhanced in the diabetic rats. and CYP2D6 activity was inhibited in a short period of diabetes; however, the decrease in CYP2D6 activity was not significant in the long period. CYP3A4 activity was decreased in a short period of diabetes and increased in a long period of diabetes but was not significant in the two periods. This study suggests the activity change rule of the CYP450 enzyme system in diabetes mellitus, which can provide a reference for precise clinical medication.
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Affiliation(s)
- Zhe Wang
- Department of Pharmacy, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Qing-Qing Li
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Cheng-Ke Huang
- Department of Pharmacy, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Yan-Yan Dong
- Department of Ultrasonography, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Li-Ping Lang
- Department of Pharmacy, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Wei Sun
- Department of Pharmacy, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Jian-Chang Qian
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China.
| | - Xiao-Dan Zhang
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China.
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Frederiksen T, Areberg J, Raoufinia A, Schmidt E, Stage TB, Brøsen K. Estimating the In Vivo Function of CYP2D6 Alleles through Population Pharmacokinetic Modeling of Brexpiprazole. Clin Pharmacol Ther 2023; 113:360-369. [PMID: 36350097 PMCID: PMC10099095 DOI: 10.1002/cpt.2791] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 11/02/2022] [Indexed: 11/11/2022]
Abstract
Accurate prediction of CYP2D6 phenotype from genotype information is important to support safe and efficacious pharmacotherapy with CYP2D6 substrates. To facilitate accurate CYP2D6 genotype-phenotype translation, there remains a need to investigate the enzyme activity associated with individual CYP2D6 alleles using large clinical data sets. This study aimed to quantify and compare the in vivo function of different CYP2D6 alleles through population pharmacokinetic (PopPK) modeling of brexpiprazole using data from 13 clinical studies. A PopPK model of brexpiprazole and its two metabolites, DM-3411 and DM-3412, was developed based on plasma concentration samples from 826 individuals. As the minor metabolite, DM-3412, is formed via CYP2D6, the metabolic ratio of DM-3412:brexpiprazole calculated from the PopPK parameter estimates was used as a surrogate measure of CYP2D6 activity. A CYP2D6 genotype-phenotype analysis based on 496 subjects showed that the CYP2D6*2 allele (n = 183) was associated with only 10% enzyme activity relative to the wild-type allele (CYP2D6*1) and a low enzyme activity was consistently observed across genotypes containing CYP2D6*2. Among the decreased function alleles, the following enzyme activities relative to CYP2D6*1 were estimated: 23% for CYP2D6*9 (n = 20), 32% for CYP2D6*10 (n = 62), 64% for CYP2D6*14 (n = 1), 4% for CYP2D6*17 (n = 37), 4% for CYP2D6*29 (n = 13), and 9% for CYP2D6*41 (n = 64). These findings imply that a lower functional value would more accurately reflect the in vivo function of many reduced function CYP2D6 alleles in the metabolism of brexpiprazole. The low enzyme activity observed for CYP2D6*2, which has also been reported by others, suggests that the allele exhibits substrate-specific enzyme activity.
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Affiliation(s)
- Trine Frederiksen
- Department of Experimental Medicine, H. Lundbeck A/S, Valby, Denmark.,Clinical Pharmacology, Pharmacy and Environmental Medicine, Department of Public Health, University of Southern Denmark, Odense, Denmark
| | - Johan Areberg
- Department of Experimental Medicine, H. Lundbeck A/S, Valby, Denmark
| | - Arash Raoufinia
- Otsuka Pharmaceutical Development & Commercialization, Inc, Rockville, Maryland, USA
| | - Ellen Schmidt
- Department of Experimental Medicine, H. Lundbeck A/S, Valby, Denmark
| | - Tore Bjerregaard Stage
- Clinical Pharmacology, Pharmacy and Environmental Medicine, Department of Public Health, University of Southern Denmark, Odense, Denmark
| | - Kim Brøsen
- Clinical Pharmacology, Pharmacy and Environmental Medicine, Department of Public Health, University of Southern Denmark, Odense, Denmark
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7
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Grzegorzewski J, Brandhorst J, König M. Physiologically based pharmacokinetic (PBPK) modeling of the role of CYP2D6 polymorphism for metabolic phenotyping with dextromethorphan. Front Pharmacol 2022; 13:1029073. [PMID: 36353484 PMCID: PMC9637881 DOI: 10.3389/fphar.2022.1029073] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 09/23/2022] [Indexed: 11/24/2022] Open
Abstract
The cytochrome P450 2D6 (CYP2D6) is a key xenobiotic-metabolizing enzyme involved in the clearance of many drugs. Genetic polymorphisms in CYP2D6 contribute to the large inter-individual variability in drug metabolism and could affect metabolic phenotyping of CYP2D6 probe substances such as dextromethorphan (DXM). To study this question, we (i) established an extensive pharmacokinetics dataset for DXM; and (ii) developed and validated a physiologically based pharmacokinetic (PBPK) model of DXM and its metabolites dextrorphan (DXO) and dextrorphan O-glucuronide (DXO-Glu) based on the data. Drug-gene interactions (DGI) were introduced by accounting for changes in CYP2D6 enzyme kinetics depending on activity score (AS), which in combination with AS for individual polymorphisms allowed us to model CYP2D6 gene variants. Variability in CYP3A4 and CYP2D6 activity was modeled based on in vitro data from human liver microsomes. Model predictions are in very good agreement with pharmacokinetics data for CYP2D6 polymorphisms, CYP2D6 activity as described by the AS system, and CYP2D6 metabolic phenotypes (UM, EM, IM, PM). The model was applied to investigate the genotype-phenotype association and the role of CYP2D6 polymorphisms for metabolic phenotyping using the urinary cumulative metabolic ratio (UCMR), DXM/(DXO + DXO-Glu). The effect of parameters on UCMR was studied via sensitivity analysis. Model predictions indicate very good robustness against the intervention protocol (i.e. application form, dosing amount, dissolution rate, and sampling time) and good robustness against physiological variation. The model is capable of estimating the UCMR dispersion within and across populations depending on activity scores. Moreover, the distribution of UCMR and the risk of genotype-phenotype mismatch could be estimated for populations with known CYP2D6 genotype frequencies. The model can be applied for individual prediction of UCMR and metabolic phenotype based on CYP2D6 genotype. Both, model and database are freely available for reuse.
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8
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Sun MZ, Zheng QC. The regioselectivity of the interaction between dextromethorphan and CYP2D6. Phys Chem Chem Phys 2022; 24:2234-2242. [PMID: 35014636 DOI: 10.1039/d1cp03933d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
CYP2D6 is an important enzyme of the cytochrome P450 superfamily, and catalyzes nearly 25% of the drugs sold in the market. For decades, the interactions and metabolism between CYP2D6 and substrates have been a hot topic. However, the key factors of the catalytic regioselectivity for CYP2D6 still remain controversial. Here, we construct four systems to explore the interaction between dextromethorphan (DM) and CYP2D6. A new binding mode of CYP2D6 is defined, and two key residues (residue Asp301 and residue Glu216) are discovered working simultaneously to stabilize the DM at the reactive site by forming water bridge hydrogen bonds when CYP2D6 binds DM. Our results also indicate that the substrate concentration could mediate the binding mode between the substrate and CYP2D6 by decreasing the volume of the catalytic pocket, which is not conducive to the O-demethylation of DM but benefits the N-demethylation of DM. These results could shed light on the process of CYP2D6 binding to the substrate, and help to better understand the regioselectivity of CYP2D6 catalyzing the substrates.
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Affiliation(s)
- Min-Zhang Sun
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, 2 Liutiao Road, Changchun 130023, P. R. China.
| | - Qing-Chuan Zheng
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, 2 Liutiao Road, Changchun 130023, P. R. China. .,Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, Jilin University, Changchun 130012, P. R. China
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9
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Ramsey LB, Gaedigk A. CYP2D6*9 and *41: Does the Activity Value Assigned to these Alleles Need to be Reduced to more Accurately Predict Phenotype? Clin Pharmacol Ther 2021; 111:1208-1211. [PMID: 34352934 DOI: 10.1002/cpt.2371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 07/13/2021] [Indexed: 11/06/2022]
Affiliation(s)
- Laura B Ramsey
- Divisions of Clinical Pharmacology and Research in Patient Services, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Andrea Gaedigk
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Children's Mercy Kansas City and School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri, USA
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10
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Molden E, Jukić MM. CYP2D6 Reduced Function Variants and Genotype/Phenotype Translations of CYP2D6 Intermediate Metabolizers: Implications for Personalized Drug Dosing in Psychiatry. Front Pharmacol 2021; 12:650750. [PMID: 33967790 PMCID: PMC8100508 DOI: 10.3389/fphar.2021.650750] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 03/23/2021] [Indexed: 12/14/2022] Open
Abstract
Genetic differences in cytochrome P450 (CYP)-mediated metabolism have been known for several decades. The clinically most important polymorphic CYP enzyme is CYP2D6, which plays a key role in the metabolism of many antidepressants and antipsychotics, along with a range of non-psychiatric medications. Dose individualization based on CYP2D6 genotype to improve the effect and safety of drug treatment has been an ambition for a long time. Clinical use of CYP2D6 genotyping is steadily increasing; however, for pre-emptive genotyping to be successful in predicting individual dose requirements, high precision of genotype-to-phenotype translations are required. Recently, guidelines for assigning CYP2D6 enzyme activity scores of CYP2D6 variant alleles, and subsequent diplotype-to-phenotype translations, were published by the Clinical Pharmacogenetics Implementation Consortium (CPIC) and the Dutch Pharmacogenetics Working Group. Consensus on assigning activity scores of CYP2D6 variant alleles and translating diplotype scores into CYP2D6 poor, intermediate, normal, or ultrarapid metabolizer groups were obtained by consulting 37 international experts. While assigning enzyme activities of non-functional (score 0) and fully functional (score 1) alleles are straightforward, reduced function variant alleles are more complex. In this article, we present data showing that the assigned activity scores of reduced function variant alleles in current guidelines are not of sufficient precision; especially not for CYP2D6*41, where the guideline activity score is 0.5 compared to 0.05–0.15 in pharmacogenetic studies. Due to these discrepancies, CYP2D6 genotypes with similar guidelinediplotype scores exhibit substantial differences in CYP2D6 metabolizer phenotypes. Thus, it is important that the guidelines are updated to be valid in predicting individual dose requirements of psychiatric drugs and others metabolized by CYP2D6.
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Affiliation(s)
- Espen Molden
- Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway.,Section for Pharmacology and Pharmaceutical Biosciences, Departement of Pharmacy, University of Oslo, Oslo, Norway
| | - Marin M Jukić
- Section of Pharmacogenetics, Department of Physiology and Pharmacology, Biomedicum 5B, Karolinska Institutet, Stockholm, Sweden.,Department of Physiology, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia
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11
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Frederiksen T, Areberg J, Schmidt E, Bjerregaard Stage T, Brøsen K. Quantification of In Vivo Metabolic Activity of CYP2D6 Genotypes and Alleles Through Population Pharmacokinetic Analysis of Vortioxetine. Clin Pharmacol Ther 2021; 109:150-159. [PMID: 32599653 PMCID: PMC7818194 DOI: 10.1002/cpt.1972] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 06/06/2020] [Indexed: 12/18/2022]
Abstract
Assignment of CYP2D6 phenotype from genotype data can be challenging and despite efforts to standardize translation, there is currently no universally accepted method. To facilitate standardization, there remains a need to precisely quantify the in vivo function of different CYP2D6 genotypes. Vortioxetine is metabolized to its major metabolite, Lu AA34443, primarily via CYP2D6. The aim of this study was to quantify the in vivo CYP2D6 activity of different CYP2D6 alleles and genotypes through population pharmacokinetic (PopPK) modeling of vortioxetine and Lu AA34443. Plasma concentration data of vortioxetine and Lu AA34443 from 1,140 subjects originating from 29 clinical pharmacology studies were pooled for the analysis. A joint PopPK model described the pharmacokinetics of vortioxetine and Lu AA34443 simultaneously and provided estimates of the CYP2D6-mediated metabolism for each subject. Subjects normally classified as CYP2D6 intermediate metabolizers (IMs) showed different levels of CYP2D6 activity with carriers of one fully functional allele and one null function allele having 77% higher CYP2D6 activity compared with carriers of two decreased function alleles (P < 0.0001). The decreased function alleles were associated with different levels of reduction of CYP2D6 activity. Fixing the activity of fully functional alleles to 1.0, the relative activities of CYP2D6*9, CYP2D6*10, CYP2D6*17, and CYP2D6*41 were 0.22, 0.37, 0.17, and 0.21, respectively. The activity of CYP2D6*10 was shown to be significantly greater than that of CYP2D6*17 (P = 0.01) and CYP2D6*41 (P = 0.02). These results warrant further discussion of current CYP2D6 genotype-phenotype classification systems particularly regarding decreased function alleles and the IM phenotype.
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Affiliation(s)
- Trine Frederiksen
- Department of Experimental MedicineH. Lundbeck A/SValbyDenmark
- Clinical Pharmacology and PharmacyDepartment of Public HealthUniversity of Southern DenmarkOdenseDenmark
| | - Johan Areberg
- Department of Experimental MedicineH. Lundbeck A/SValbyDenmark
| | - Ellen Schmidt
- Department of Experimental MedicineH. Lundbeck A/SValbyDenmark
| | - Tore Bjerregaard Stage
- Clinical Pharmacology and PharmacyDepartment of Public HealthUniversity of Southern DenmarkOdenseDenmark
| | - Kim Brøsen
- Clinical Pharmacology and PharmacyDepartment of Public HealthUniversity of Southern DenmarkOdenseDenmark
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12
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Zanger UM, Momoi K, Hofmann U, Schwab M, Klein K. Tri-Allelic Haplotypes Determine and Differentiate Functionally Normal Allele CYP2D6*2 and Impaired Allele CYP2D6*41. Clin Pharmacol Ther 2020; 109:1256-1264. [PMID: 33043448 DOI: 10.1002/cpt.2078] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 10/05/2020] [Indexed: 12/14/2022]
Abstract
CYP2D6 metabolizes 20-25% of all clinically used drugs and its complex genetic polymorphism is a major determinant of drug safety and efficacy. We investigated the basis for the functional difference between the two common alleles *2 (g.2851C>T + g.4181G>C, normal function) and *41 (additional intronic g.2989G>A, reduced function). A recently reported far-distant enhancer polymorphism rs5758550A/G linked to *2 has been suggested to play a decisive role. Genotyping of two white cohorts confirmed strong linkage of rs5758550G to *2, whereas no influence was found on metabolic ratio of sparteine or hepatic expression. Genomic plasmid constructs carrying individual variants or combinations thereof were expressed in COS1 and Huh7 cells. Both g.2851C>T(R296C) and g.2989G>A reduced enzyme activity and protein levels similarly by ~ 50-65% compared to reference (*1), whereas the double variant had only ~ 20% activity. Although the unexpected loss of function caused by g.2851C>T was compensated by g.4181G>C (mimicking the EM-phenotype of *2), the additional loss of function due to intronic g.2989G>A in the triple variant was not compensated (mimicking the IM-phenotype of *41). We also confirmed increased erroneous splicing in carriers of g.2989G>A but not of g.2851C>T as a likely explanation for the impaired function of *41. In conclusion, our data demonstrate g.2989G>A as causal variant of impaired allele CYP2D6*41 whereas triple-haplotypes have to be considered to explain the functional difference between *2 and *41. These data are important for genotyping strategies and clinical implementation of CYP2D6 pharmacogenetics.
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Affiliation(s)
- Ulrich M Zanger
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany
- University of Tuebingen, Tuebingen, Germany
| | - Kyoko Momoi
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany
- University of Tuebingen, Tuebingen, Germany
| | - Ute Hofmann
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany
- University of Tuebingen, Tuebingen, Germany
| | - Matthias Schwab
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany
- University of Tuebingen, Tuebingen, Germany
- Departments of Clinical Pharmacology, and of Pharmacy and Biochemistry, University Tuebingen, Tuebingen, Germany
| | - Kathrin Klein
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany
- University of Tuebingen, Tuebingen, Germany
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13
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Silva AR, Dinis-Oliveira RJ. Pharmacokinetics and pharmacodynamics of dextromethorphan: clinical and forensic aspects. Drug Metab Rev 2020; 52:258-282. [DOI: 10.1080/03602532.2020.1758712] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Ana Rita Silva
- Department of Public Health and Forensic Sciences, and Medical Education, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Ricardo Jorge Dinis-Oliveira
- Department of Public Health and Forensic Sciences, and Medical Education, Faculty of Medicine, University of Porto, Porto, Portugal
- Department of Sciences, IINFACTS – Institute of Research and Advanced Training in Health Sciences and Technologies, University Institute of Health Sciences (IUCS), CESPU, CRL, Gandra, Portugal
- Department of Biological Sciences, Faculty of Pharmacy, Laboratory of Toxicology, UCIBIO, REQUIMTE, University of Porto, Porto, Portugal
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14
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Boone EC, Wang WY, Gaedigk R, Cherner M, Bérard A, Leeder JS, Miller NA, Gaedigk A. Long-Distance Phasing of a Tentative "Enhancer" Single-Nucleotide Polymorphism With CYP2D6 Star Allele Definitions. Front Pharmacol 2020; 11:486. [PMID: 32457600 PMCID: PMC7226225 DOI: 10.3389/fphar.2020.00486] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 03/27/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The CYP2D6 gene locus has been extensively studied over decades, yet a portion of variability in CYP2D6 activity cannot be explained by known sequence variations within the gene, copy number variation, or structural rearrangements. It was proposed that rs5758550, located 116 kb downstream of the CYP2D6 gene locus, increases gene expression and thus contributes to variability in CYP2D6 activity. This finding has, however, not been validated. The purpose of the study was to address a major technological barrier, i.e., experimentally linking rs5758550, also referred to as the "enhancer" single-nucleotide polymorphism (SNP), to CYP2D6 haplotypes >100 kb away. To overcome this challenge is essential to ultimately determine the contribution of the "enhancer" SNP to interindividual variability in CYP2D6 activity. METHODS A large ethnically mixed population sample (n=3,162) was computationally phased to determine linkage between the "enhancer" SNP and CYP2D6 haplotypes (or star alleles). To experimentally validate predicted linkages, DropPhase2D6, a digital droplet PCR (ddPCR)-based method was developed. 10X Genomics Linked-Reads were utilized as a proof of concept. RESULTS Phasing predicted that the "enhancer" SNP can occur on numerous CYP2D6 haplotypes including CYP2D6*1, *2, *5, and *41 and suggested that linkage is incomplete, i.e., a portion of these alleles do not have the "enhancer" SNP. Phasing also revealed differences among the European and African ancestry data sets regarding the proportion of alleles with and without the "enhancer" SNP. DropPhase2D6 was utilized to confirm or refute the predicted "enhancer" SNP location for individual samples, e.g., of n=3 samples genotyped as *1/*41, rs5758550 was on the *41 allele of two samples and on the *1 allele of one sample. Our findings highlight that the location of the "enhancer" SNP must not be assigned by "default." Furthermore, linkage between the "enhancer" SNP and CYP2D6 star allele haplotypes was confirmed with 10X Genomics technology. CONCLUSIONS Since the "enhancer" SNP can be present on a portion of normal, decreased, or no function alleles, the phase of the "enhancer" SNP must be considered when investigating the impact of the "enhancer" SNP on CYP2D6 activity.
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Affiliation(s)
- Erin C. Boone
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, MO, United States
| | - Wendy Y. Wang
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, MO, United States
| | - Roger Gaedigk
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, MO, United States
- School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Mariana Cherner
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, United States
| | - Anick Bérard
- Faculty of Pharmacy, University of Montreal, Montreal, QC, Canada
- Research Center, CHU Sainte-Justine, Montreal, QC, Canada
| | - J. Steven Leeder
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, MO, United States
- School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Neil A. Miller
- School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
- Center for Pediatric Genomic Medicine, Children's Mercy Kansas City, Kansas City, MO, United States
| | - Andrea Gaedigk
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, MO, United States
- School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
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15
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Faisal M, Cawello W, Burckhardt BB, de Hoon J, Laer S. Simultaneous Semi-Mechanistic Population Pharmacokinetic Modeling Analysis of Enalapril and Enalaprilat Serum and Urine Concentrations From Child Appropriate Orodispersible Minitablets. Front Pediatr 2019; 7:281. [PMID: 31338356 PMCID: PMC6629781 DOI: 10.3389/fped.2019.00281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 06/24/2019] [Indexed: 11/20/2022] Open
Abstract
Enalapril is recommended as the first line of therapy and is proven to improve survival rates for treatment of Pediatric Heart Failure; however, an approved drug and child appropriate dosage formulation is still absent. The present analysis was conducted to perform a detailed model informed population pharmacokinetic analysis of prodrug enalapril and its active metabolite enalaprilat in serum and urine. Further, a model informed dosage form population-pharmacokinetic analysis was conducted to evaluate differences in pharmacokinetics of enalapril and its active metabolite enalaprilat when prodrug was administered to 24 healthy adults in a crossover, two periods, two treatments, phase I clinical trial using child-appropriate orodispersible mini-tablets (ODMT) and reference (Renitec®) dosage formulation. A simultaneous semi-mechanistic population-pharmacokinetic model was developed using NONMEM software, which predicted full profile serum and urine concentrations of enalapril and enalaprilat. First-order conditional estimation with interaction was used for parameter estimation. Transit compartments added using Erlang distribution method to predicted enalapril absorption and enalaprilat formation phases. Normalized body weight was identified as covariate related to enalapril volume of distribution. Visual predictive check (VPC) plots and conducted bootstrap analysis validated the model. The data from the two formulations were pooled for population-pharmacokinetic analysis and covariate effect of the formulation was found on mean transit time (MTT1) of enalapril absorption. In addition, data of each formulation were modeled separately and the estimated parameters of each individual administered both formulations were correlated using paired samples Wilcoxon rank test (p < 0.05 = significant) which also showed only a significant difference (p = 0.03) in MTT1 i.e., 5 min early appearance of enalapril from ODMT compared to reference tablets. No difference in the pharmacokinetics of active enalaprilat was found from the ODMT compared to the reference formulation. The population pharmacokinetic analysis provided detailed information about the pharmacokinetics of enalapril and enalaprilat, which showed that the ODMT formulation might have similar pharmacodynamic response compared to the reference formulation.
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Affiliation(s)
- Muhammad Faisal
- Institute of Clinical Pharmacy and Pharmacotherapy, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Willi Cawello
- Institute of Clinical Pharmacy and Pharmacotherapy, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Bjoern B Burckhardt
- Institute of Clinical Pharmacy and Pharmacotherapy, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Jan de Hoon
- Center for Clinical Pharmacology, University Hospitals Leuven/KU Leuven, Leuven, Belgium
| | - Stephanie Laer
- Institute of Clinical Pharmacy and Pharmacotherapy, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
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16
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Haslemo T, Eliasson E, Jukić MM, Ingelman-Sundberg M, Molden E. Significantly lower CYP2D6 metabolism measured as the O/N-desmethylvenlafaxine metabolic ratio in carriers of CYP2D6*41 versus CYP2D6*9 or CYP2D6*10: a study on therapeutic drug monitoring data from 1003 genotyped Scandinavian patients. Br J Clin Pharmacol 2018; 85:194-201. [PMID: 30312494 DOI: 10.1111/bcp.13788] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 09/26/2018] [Accepted: 09/30/2018] [Indexed: 12/11/2022] Open
Abstract
AIMS CYP2D6*9, CYP2D6*10 and CYP2D6*41 are the most frequent reduced-function CYP2D6 alleles in Caucasians. Despite lacking in vivo evidence, they are collectively classified with an enzyme activity score of 0.5. Thus, the aim of this study was to compare the functional impact of CYP2D6*9, CYP2D6*10 and CYP2D6*41 on CYP2D6 metabolism in a large patient population. METHODS A total of 1003 patients (mainly Caucasians) with data on CYP2D6 genotype and serum concentrations of venlafaxine and metabolites were included from a therapeutic drug monitoring service in Oslo, Norway. The O-desmethyl-to-N-desmethyl-venlafaxine metabolic ratio (MR) was applied as CYP2D6 biomarker and compared (Mann-Whitney) between carriers of CYP2D6*9-10 (merged) and CYP2D6*41, either combined with CYP2D6*1 or non-coding (null) alleles. MR subgroup estimates were obtained by multiple linear regression for calculations of CYP2D6*9-10 and CYP2D6*41 activity scores. RESULTS MR was significantly lower in carriers of CYP2D6*41 than CYP2D6*9-10 (P < 0.002). The majority of CYP2D6*41/null carriers (86.7%) had MR in the observed range of CYP2D6null/null carriers compared with the minority of CYP2D6*9-10/null carriers (17.4%). CYP2D6 genotype explained 60.7% of MR variability in the multivariate analysis providing subgroup estimates of 9.54 (95% CI; 7.45-12.20), 3.55 (2.06-6.10), 1.33 (0.87-2.05) and 0.47 (0.35-0.61) in carriers of CYP2D6*1/null (n = 269), CYP2D6*9-10/null (n = 17), CYP2D6*41/null (n = 30) and CYP2D6null/null (n = 95), respectively. Based on these estimates, the calculated activity score of CYP2D6*41 was 0.095 compared to 0.34 for CYP2D6*9-10. CONCLUSIONS CYP2D6 metabolism measured as the O/N-desmethylvenlafaxine ratio is significantly lower in Scandinavian carriers of CYP2D6*41 vs. CYP2D6*9-10. Thus, these alleles should be differentiated when classifying CYP2D6 phenotype from genotype.
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Affiliation(s)
- Tore Haslemo
- Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway
| | - Erik Eliasson
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institute, Karolinska University Hospital, Stockholm, Sweden
| | - Marin M Jukić
- Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden.,Department of Physiology, Faculty of Pharmacy, University of Belgrade, Serbia
| | - Magnus Ingelman-Sundberg
- Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - Espen Molden
- Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway.,Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
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17
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Microsecond MD simulations of human CYP2D6 wild-type and five allelic variants reveal mechanistic insights on the function. PLoS One 2018; 13:e0202534. [PMID: 30133539 PMCID: PMC6104999 DOI: 10.1371/journal.pone.0202534] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 08/03/2018] [Indexed: 11/19/2022] Open
Abstract
Characterization of cytochrome P450 2D6 (CYP2D6) and the impact of the major identified allelic variants on the activity of one of the most dominating drug-metabolising enzymes is essential to increase drug safety and avoid adverse reactions. Microsecond molecular dynamics simulations have been performed to capture the dynamic signatures of this complex enzyme and five allelic variants with diverse enzymatic activity. In addition to the apo simulations, three substrates (bufuralol, veliparib and tamoxifen) and two inhibitors (prinomastat and quinidine) were included to explore their influence on the structure and dynamical features of the enzyme. Our results indicate that the altered enzyme activity can be attributed to changes in the hydrogen bonding network within the active site, and local structural differences in flexibility, position and shape of the binding pocket. In particular, the increased (CYP2D6*53) or the decreased (CYP2D6*17) activity seems to be related to a change in dynamics of mainly the BC loop due to a modified hydrogen bonding network around this region. In addition, the smallest active site volume was found for CYP2D6*4 (no activity). CYP2D6*2 (normal activity) showed no major differences in dynamic behaviour compared to the wild-type.
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18
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Baird JK, Louisa M, Noviyanti R, Ekawati L, Elyazar I, Subekti D, Chand K, Gayatri A, Instiaty, Soebianto S, Crenna-Darusallam C, Djoko D, Hasto BD, Meriyenes D, Wesche D, Nelwan EJ, Sutanto I, Sudoyo H, Setiabudy R. Association of Impaired Cytochrome P450 2D6 Activity Genotype and Phenotype With Therapeutic Efficacy of Primaquine Treatment for Latent Plasmodium vivax Malaria. JAMA Netw Open 2018; 1:e181449. [PMID: 30646129 PMCID: PMC6324265 DOI: 10.1001/jamanetworkopen.2018.1449] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
IMPORTANCE Latent hepatic Plasmodium vivax hypnozoites provoke repeated clinical attacks called relapses. Only primaquine phosphate kills hypnozoites, and its therapeutic activity may depend on naturally polymorphic cytochrome P450 2D6 isotype (CYP2D6) activity. OBJECTIVE To examine the association of impaired CYP2D6 genotypes and CYP2D6 metabolic phenotypes with therapeutic failure of directly observed high-dose primaquine treatment for P vivax malaria relapse. DESIGN, SETTING, AND PARTICIPANTS Nested case-control study of patients who, in July 2014, completed a randomized clinical trial of directly observed primaquine treatment for radical cure of acute P vivax malaria in an area of Indonesia where reinfection during 1 year of posttreatment follow-up was improbable. A total of 177 of 180 patients with P vivax malaria completed the clinical trial of primaquine treatment to prevent relapse; 151 were eligible for recruitment as controls. After screening, 59 potential control individuals (no relapse) and 26 potential case patients (relapse) were considered, and 36 controls and 21 cases were enrolled. EXPOSURES Cases and controls were exposed to P vivax malaria and primaquine therapy but had variable exposure to the enzymatic activity of CYP2D6, classified as impaired by a genotype-determined qualitative phenotype (poor or intermediate), genotype-determined activity score less than 1.5, or a log of the 24-hour pooled urine dextromethorphan-dextrorphan metabolic ratio greater than -1.0. MAIN OUTCOMES AND MEASURES Unadjusted odds ratios (ORs) of relapse with impaired CYP2D6 metabolism determined by genotype or measured by urinary dextromethorphan-dextrorphan metabolic ratio. RESULTS Among the 21 cases (mean [SD] age, 30.5 [6.3] years; all male) and 36 controls (mean [SD] age, 29.0 [3.6] years; all male), 6 CYP2D6 alleles (*1, *2, *4, *5, *10, and *41) occurred as 12 distinct genotypes, with model activity scores ranging from 0.0 to 2.0. Among 32 patients with genotypic activity scores of 1.0 or less, 18 had experienced relapse, whereas among the 25 with scores higher than 1.0, 3 had experienced relapse (OR, 9.4; 95% CI, 2.1-57.0; P = .001). When the log of the metabolic ratio of dextromethorphan-dextrorphan was -1.0 or less, only 1 of 18 patients experienced relapse, whereas above that threshold (consistent with low metabolic activity), 20 of 39 patients experienced relapse (OR, 18; 95% CI, 2.2-148.0; P = .007). CONCLUSIONS AND RELEVANCE Genotype-determined and directly measured impaired levels of CYP2D6 activity were associated with elevated risk of therapeutic failure. These findings suggest a natural variability in CYP2D6-dependent metabolism of primaquine as a key determinant of therapeutic efficacy against latent P vivax malaria.
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Affiliation(s)
- J. Kevin Baird
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Eijkman-Oxford Clinical Research Unit, Eijkman Institute of Molecular Biology, Central Jakarta, Indonesia
| | - Melva Louisa
- Department of Pharmacology, Faculty of Medicine Universitas Indonesia, Jalan Salemba Raya No. 6, Central Jakarta, Indonesia
| | - Rintis Noviyanti
- Eijkman Institute of Molecular Biology, Central Jakarta, Indonesia
| | - Lenny Ekawati
- Eijkman-Oxford Clinical Research Unit, Eijkman Institute of Molecular Biology, Central Jakarta, Indonesia
| | - Iqbal Elyazar
- Eijkman-Oxford Clinical Research Unit, Eijkman Institute of Molecular Biology, Central Jakarta, Indonesia
| | - Decy Subekti
- Eijkman-Oxford Clinical Research Unit, Eijkman Institute of Molecular Biology, Central Jakarta, Indonesia
| | - Krisin Chand
- Eijkman-Oxford Clinical Research Unit, Eijkman Institute of Molecular Biology, Central Jakarta, Indonesia
| | - Anggi Gayatri
- Department of Pharmacology, Faculty of Medicine Universitas Indonesia, Jalan Salemba Raya No. 6, Central Jakarta, Indonesia
| | - Instiaty
- Department of Pharmacology, Faculty of Medicine Universitas Indonesia, Jalan Salemba Raya No. 6, Central Jakarta, Indonesia
| | - Saraswati Soebianto
- Eijkman-Oxford Clinical Research Unit, Eijkman Institute of Molecular Biology, Central Jakarta, Indonesia
| | | | - Dwi Djoko
- Army Health Command, East Jakarta, Indonesia
| | | | | | - David Wesche
- Certara Strategic Consulting, Princeton, New Jersey
| | - Erni J. Nelwan
- Division of Tropical Infectious Diseases, Faculty of Medicine, Universitas Indonesia, Central Jakarta, Indonesia
| | - Inge Sutanto
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Central Jakarta, Indonesia
| | - Herawati Sudoyo
- Eijkman Institute of Molecular Biology, Central Jakarta, Indonesia
| | - Rianto Setiabudy
- Department of Pharmacology, Faculty of Medicine Universitas Indonesia, Jalan Salemba Raya No. 6, Central Jakarta, Indonesia
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19
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Gazzaz M, Kinzig M, Schaeffeler E, Jübner M, Hsin CH, Li X, Taubert M, Trueck C, Iltgen-Breburda J, Kraus D, Queckenberg C, Stoffel M, Schwab M, Sörgel F, Fuhr U. Drinking Ethanol Has Few Acute Effects on CYP2C9, CYP2C19, NAT2, and P-Glycoprotein Activities but Somewhat Inhibits CYP1A2, CYP2D6, and Intestinal CYP3A: So What? Clin Pharmacol Ther 2018; 104:1249-1259. [DOI: 10.1002/cpt.1083] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/02/2018] [Accepted: 03/29/2018] [Indexed: 11/11/2022]
Affiliation(s)
- Malaz Gazzaz
- Department I of Pharmacology; University Hospital Cologne; Germany
- Department of Clinical Pharmacy, College of Pharmacy; Umm Al-Qura University; Makkah Saudi Arabia
| | - Martina Kinzig
- Institute for Biomedical and Pharmaceutical Research, Nürnberg-Heroldsberg; Germany
| | - Elke Schaeffeler
- Dr. Margarete-Fischer-Bosch Institute of Clinical Pharmacology; Stuttgart Germany
- University of Tuebingen; Tuebingen Germany
| | - Martin Jübner
- Institute of Legal Medicine, Faculty of Medicine; University of Cologne; Germany
| | - Chih-hsuan Hsin
- Department I of Pharmacology; University Hospital Cologne; Germany
| | - Xia Li
- Department I of Pharmacology; University Hospital Cologne; Germany
| | - Max Taubert
- Department I of Pharmacology; University Hospital Cologne; Germany
| | - Christina Trueck
- Department I of Pharmacology; University Hospital Cologne; Germany
| | | | - Daria Kraus
- Department I of Pharmacology; University Hospital Cologne; Germany
- Clinical Trials Centre; University Hospital Cologne; Germany
| | - Christian Queckenberg
- Department I of Pharmacology; University Hospital Cologne; Germany
- Clinical Trials Centre; University Hospital Cologne; Germany
| | - Marc Stoffel
- Department I of Pharmacology; University Hospital Cologne; Germany
| | - Matthias Schwab
- Dr. Margarete-Fischer-Bosch Institute of Clinical Pharmacology; Stuttgart Germany
- Department of Clinical Pharmacology; University Hospital Tuebingen; Germany
- Department of Pharmacy and Biochemistry; University of Tuebingen; Tuebingen Germany
| | - Fritz Sörgel
- Institute for Biomedical and Pharmaceutical Research, Nürnberg-Heroldsberg; Germany
- Institute of Pharmacology; Faculty of Medicine, University Duisburg-Essen; Essen Germany
| | - Uwe Fuhr
- Department I of Pharmacology; University Hospital Cologne; Germany
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20
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Ten Years' Experience with the CYP2D6 Activity Score: A Perspective on Future Investigations to Improve Clinical Predictions for Precision Therapeutics. J Pers Med 2018; 8:jpm8020015. [PMID: 29673183 PMCID: PMC6023391 DOI: 10.3390/jpm8020015] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 04/06/2018] [Accepted: 04/10/2018] [Indexed: 12/20/2022] Open
Abstract
The seminal paper on the CYP2D6 Activity Score (AS) was first published ten years ago and, since its introduction in 2008, it has been widely accepted in the field of pharmacogenetics. This scoring system facilitates the translation of highly complex CYP2D6 diplotype data into a patient’s phenotype to guide drug therapy and is at the core of all CYP2D6 gene/drug pair guidelines issued by the Clinical Pharmacogenetics Implementation Consortium (CPIC). The AS, however, only explains a portion of the variability observed among individuals and ethnicities. In this review, we provide an overview of sources in addition to CYP2D6 genotype that contribute to the variability in CYP2D6-mediated drug metabolism and discuss other factors, genetic and non-genetic, that likely contribute to the observed variability in CYP2D6 enzymatic activity.
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21
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Aoyama T, Ishida Y, Kaneko M, Miyamoto A, Saito Y, Tohkin M, Kawai S, Matsumoto Y. Pharmacokinetics and Pharmacodynamics of Meloxicam in East Asian Populations: The Role of Ethnicity on Drug Response. CPT-PHARMACOMETRICS & SYSTEMS PHARMACOLOGY 2017; 6:823-832. [PMID: 29024493 PMCID: PMC5744175 DOI: 10.1002/psp4.12259] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 04/08/2017] [Accepted: 10/05/2017] [Indexed: 01/08/2023]
Abstract
We aimed to reanalyze the differences in the pharmacokinetics (PKs) of meloxicam in East Asian populations based on a population approach using previously published data and to investigate the factors found in population PK analysis that affect the pharmacodynamics (PDs) of meloxicam. Population PK analysis was performed in 119 healthy male subjects (30 Japanese, 30 Chinese, 29 Korean, and 30 white) under strictly controlled trial conditions with regulated meals and a single lot of the drug. We found that CYP2C9 genotype and lean body mass were statistically significant predictors of clearance and volume of distribution, respectively. A statistical significant difference in the PK parameters between ethnic groups could not be identified. Simulations using PK/PD models showed that CYP2C9 genotype is the factor that affects the PDs of meloxicam. The genetic polymorphisms highlighted in this study would be beneficial for conducting clinical trials in East Asians with similar genetic backgrounds.
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Affiliation(s)
- Takahiko Aoyama
- Laboratory of Clinical Pharmacokinetics, School of Pharmacy, Nihon University, Chiba, Japan
| | - Yoshimasa Ishida
- Laboratory of Clinical Pharmacokinetics, School of Pharmacy, Nihon University, Chiba, Japan.,Clinical Pharmacology Strategy, Japan Medical and Development, Bristol-Myers Squibb, Tokyo, Japan
| | - Masato Kaneko
- Laboratory of Clinical Pharmacokinetics, School of Pharmacy, Nihon University, Chiba, Japan.,Clinical Sciences Japan, Bayer Yakuhin, Ltd, Osaka, Japan
| | - Aoi Miyamoto
- Laboratory of Clinical Pharmacokinetics, School of Pharmacy, Nihon University, Chiba, Japan
| | - Yoshiro Saito
- Biochemistry and Immunochemistry, National Institute of Health Science, Tokyo, Japan
| | - Masahiro Tohkin
- Division of Medicinal Safety Science, National Institute of Health Science, Tokyo, Japan.,Department of Regulatory Science, Graduate School of Pharmaceutical Sciences, Nagoya City University, Aichi, Japan
| | - Shinichi Kawai
- Department of Inflammation and Pain Control Research, Toho University School of Medicine, Tokyo, Japan
| | - Yoshiaki Matsumoto
- Laboratory of Clinical Pharmacokinetics, School of Pharmacy, Nihon University, Chiba, Japan
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Lack of ethnic differences of moxifloxacin and metabolite pharmacokinetics in East Asian men. J Pharmacokinet Pharmacodyn 2017; 45:199-214. [DOI: 10.1007/s10928-017-9556-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 11/16/2017] [Indexed: 10/18/2022]
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St Sauver JL, Olson JE, Roger VL, Nicholson WT, Black JL, Takahashi PY, Caraballo PJ, Bell EJ, Jacobson DJ, Larson NB, Bielinski SJ. CYP2D6 phenotypes are associated with adverse outcomes related to opioid medications. Pharmgenomics Pers Med 2017. [PMID: 28769582 DOI: 10.2147/pgpm.s136341.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Variation in the CYP2D6 gene may affect response to opioids in both poor and ultrarapid metabolizers, but data demonstrating such associations have been mixed, and the impact of variants on toxicity-related symptoms (e.g., nausea) is unclear. Therefore, we examined the association between CYP2D6 phenotype and poor pain control or other adverse symptoms related to the use of opioids in a sample of primary care patients. MATERIALS AND METHODS We identified all patients in the Mayo Clinic RIGHT Protocol who were prescribed an opioid medication between July 01, 2013 and June 30, 2015, and categorized patients into three phenotypes: poor, intermediate to extensive, or ultrarapid CYP2D6 metabolizers. We reviewed the electronic health record of these patients for indications of poor pain control or adverse symptoms related to medication use. Associations between phenotype and outcomes were assessed using Chi-square tests and logistic regression. RESULTS Overall, 257 (25% of RIGHT Protocol participants) patients received at least one opioid prescription; of these, 40 (15%) were poor metabolizers, 146 (57%) were intermediate to extensive metabolizers, and 71 (28%) were ultrarapid metabolizers. We removed patients that were prescribed a CYP2D6 inhibitor medication (n=38). After adjusting for age and sex, patients with a poor or ultrarapid phenotype were 2.7 times more likely to experience either poor pain control or an adverse symptom related to the prescription compared to patients with an intermediate to extensive phenotype (odds ratio: 2.68; 95% CI: 1.39, 5.17; p=0.003). CONCLUSION Our results suggest that >30% of patients with a poor or ultrarapid CYP2D6 phenotype may experience an adverse outcome after being prescribed codeine, tramadol, oxycodone, or hydrocodone. These medications are frequently prescribed for pain relief, and ~39% of the US population is expected to carry one of these phenotypes, suggesting that the population-level impact of these gene-drug interactions could be substantial.
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Affiliation(s)
- Jennifer L St Sauver
- Department of Health Sciences Research.,Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester
| | - Janet E Olson
- Department of Health Sciences Research.,Center for Individualized Medicine
| | - Veronique L Roger
- Department of Health Sciences Research.,Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester.,Department of Cardiovascular Diseases
| | | | - John L Black
- Center for Individualized Medicine.,Department of Laboratory Medicine and Pathology
| | - Paul Y Takahashi
- Department of Primary Care Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Pedro J Caraballo
- Department of Primary Care Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Elizabeth J Bell
- Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester
| | - Debra J Jacobson
- Department of Health Sciences Research.,Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester
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24
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St Sauver JL, Olson JE, Roger VL, Nicholson WT, Black JL, Takahashi PY, Caraballo PJ, Bell EJ, Jacobson DJ, Larson NB, Bielinski SJ. CYP2D6 phenotypes are associated with adverse outcomes related to opioid medications. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2017; 10:217-227. [PMID: 28769582 PMCID: PMC5533497 DOI: 10.2147/pgpm.s136341] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Background Variation in the CYP2D6 gene may affect response to opioids in both poor and ultrarapid metabolizers, but data demonstrating such associations have been mixed, and the impact of variants on toxicity-related symptoms (e.g., nausea) is unclear. Therefore, we examined the association between CYP2D6 phenotype and poor pain control or other adverse symptoms related to the use of opioids in a sample of primary care patients. Materials and methods We identified all patients in the Mayo Clinic RIGHT Protocol who were prescribed an opioid medication between July 01, 2013 and June 30, 2015, and categorized patients into three phenotypes: poor, intermediate to extensive, or ultrarapid CYP2D6 metabolizers. We reviewed the electronic health record of these patients for indications of poor pain control or adverse symptoms related to medication use. Associations between phenotype and outcomes were assessed using Chi-square tests and logistic regression. Results Overall, 257 (25% of RIGHT Protocol participants) patients received at least one opioid prescription; of these, 40 (15%) were poor metabolizers, 146 (57%) were intermediate to extensive metabolizers, and 71 (28%) were ultrarapid metabolizers. We removed patients that were prescribed a CYP2D6 inhibitor medication (n=38). After adjusting for age and sex, patients with a poor or ultrarapid phenotype were 2.7 times more likely to experience either poor pain control or an adverse symptom related to the prescription compared to patients with an intermediate to extensive phenotype (odds ratio: 2.68; 95% CI: 1.39, 5.17; p=0.003). Conclusion Our results suggest that >30% of patients with a poor or ultrarapid CYP2D6 phenotype may experience an adverse outcome after being prescribed codeine, tramadol, oxycodone, or hydrocodone. These medications are frequently prescribed for pain relief, and ~39% of the US population is expected to carry one of these phenotypes, suggesting that the population-level impact of these gene–drug interactions could be substantial.
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Affiliation(s)
- Jennifer L St Sauver
- Department of Health Sciences Research.,Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester
| | - Janet E Olson
- Department of Health Sciences Research.,Center for Individualized Medicine
| | - Veronique L Roger
- Department of Health Sciences Research.,Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester.,Department of Cardiovascular Diseases
| | | | - John L Black
- Center for Individualized Medicine.,Department of Laboratory Medicine and Pathology
| | - Paul Y Takahashi
- Department of Primary Care Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Pedro J Caraballo
- Department of Primary Care Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Elizabeth J Bell
- Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester
| | - Debra J Jacobson
- Department of Health Sciences Research.,Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester
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25
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Gao J, Tian X, Zhou J, Cui MZ, Zhang HF, Gao N, Wen Q, Qiao HL. From Genotype to Phenotype: Cytochrome P450 2D6-Mediated Drug Clearance in Humans. Mol Pharm 2017; 14:649-657. [DOI: 10.1021/acs.molpharmaceut.6b00920] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Jie Gao
- Institute
of Clinical Pharmacology, Zhengzhou University, Zhengzhou, Henan 450052, China
| | - Xin Tian
- Institute
of Clinical Pharmacology, Zhengzhou University, Zhengzhou, Henan 450052, China
| | - Jun Zhou
- Institute
of Clinical Pharmacology, Zhengzhou University, Zhengzhou, Henan 450052, China
| | - Ming-Zhu Cui
- Institute
of Clinical Pharmacology, Zhengzhou University, Zhengzhou, Henan 450052, China
| | - Hai-Feng Zhang
- Institute
of Clinical Pharmacology, Zhengzhou University, Zhengzhou, Henan 450052, China
| | - Na Gao
- Institute
of Clinical Pharmacology, Zhengzhou University, Zhengzhou, Henan 450052, China
| | - Qiang Wen
- Institute
of Clinical Pharmacology, Zhengzhou University, Zhengzhou, Henan 450052, China
| | - Hai-Ling Qiao
- Institute
of Clinical Pharmacology, Zhengzhou University, Zhengzhou, Henan 450052, China
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26
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Corado CR, McKemie DS, Knych HK. Pharmacokinetics of dextromethorphan and its metabolites in horses following a single oral administration. Drug Test Anal 2016; 9:880-887. [DOI: 10.1002/dta.2060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/28/2016] [Accepted: 08/29/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Carley R. Corado
- K.L. Maddy Analytical Chemistry Laboratory, School of Veterinary Medicine; University of California; Davis CA 95620 USA
| | - Daniel S. McKemie
- K.L. Maddy Analytical Chemistry Laboratory, School of Veterinary Medicine; University of California; Davis CA 95620 USA
| | - Heather K. Knych
- K.L. Maddy Analytical Chemistry Laboratory, School of Veterinary Medicine; University of California; Davis CA 95620 USA
- Department of Veterinary Molecular Biosciences, School of Veterinary Medicine; University of California; Davis CA 95620 USA
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27
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Chen R, Rostami-Hodjegan A, Wang H, Berk D, Shi J, Hu P. Application of a physiologically based pharmacokinetic model for the evaluation of single-point plasma phenotyping method of CYP2D6. Eur J Pharm Sci 2016; 92:131-6. [PMID: 27412587 DOI: 10.1016/j.ejps.2016.07.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 07/01/2016] [Accepted: 07/01/2016] [Indexed: 10/21/2022]
Abstract
PURPOSE Determining metabolic ratio from single-point plasma is potentially a good phenotyping method of CYP2D6 to reduce the required time interval and increase the reliability of data. It is difficult to conduct large sample size clinical trials to evaluate this phenotyping method for multiple plasma points. A physiologically based pharmacokinetic (PBPK) model can be developed to do simulations based on the large virtual Chinese population and evaluate single-point plasma phenotyping method of CYP2D6. METHODS Pharmacokinetic data of dextromethorphan (DM) and its metabolite dextrorphan (DX) after oral administration were used for model development. The SimCYP® model incorporating Chinese demographic, physiological, and enzyme data was used to simulate DM and DX pharmacokinetics in different phenotype groups. RESULTS The ratios of the simulated to the observed mean AUC and Cmax of DM were 1.01 and 0.81 for extensive metabolizers (EMs), 0.90 and 0.81 for intermediate metabolizers (IMs), and 1.12 and 0.84 for poor metabolizers (PMs). The ratios of the simulated to the observed mean AUC and Cmax of DX were 1.12 and 0.89 for EMs, 0.66 and 0.62 for IMs. All ratios were within the predefined criterion of 0.5-2. The simulations of DM and DX pharmacokinetic profiles in 1000 virtual Chinese subjects with reported frequencies of different phenotypes indicated that statistically significant correlations were found between metabolic ratio of DM to DX (MRDM/DX) from AUC and from single-point plasma from 1 to 30h (all p-values <0.001). CONCLUSION MRDM/DX from single-point plasma from 1 to 30h after the administration of 30mg controlled-release DM could predict the MRDM/DX from AUC well and could be used as the phenotyping method of CYP2D6 for EMs, IMs, and PMs.
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Affiliation(s)
- Rui Chen
- Clinical Pharmacology Research Center, Peking Union Medical College Hospital, Beijing, China
| | - Amin Rostami-Hodjegan
- Manchester Pharmacy School, University of Manchester, Manchester, UK; Simcyp Limited (a Certara Company), Blades Enterprise Centre, Sheffield, UK
| | - Haotian Wang
- Cardiology Department, Beijing Tsinghua Chang Gung Hospital, Beijing, China
| | - David Berk
- Manchester Pharmacy School, University of Manchester, Manchester, UK
| | - Jun Shi
- Roche Innovation Center Shanghai, Shanghai, China
| | - Pei Hu
- Clinical Pharmacology Research Center, Peking Union Medical College Hospital, Beijing, China.
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28
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Influence of the cytochrome P450 2D6 *10/*10 genotype on the pharmacokinetics of paroxetine in Japanese patients with major depressive disorder: a population pharmacokinetic analysis. Pharmacogenet Genomics 2016; 26:403-13. [PMID: 27187662 DOI: 10.1097/fpc.0000000000000228] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Although the reduced function of the cytochrome P450 2D6*10 (CYP2D6*10) allele is common among Asian populations, existing evidence does not support paroxetine therapy adjustments for patients who have the CYP2D6*10 allele. In this study, we attempted to evaluate the degree of the impact of different CYP2D6 genotypes on the pharmacokinetic (PK) variability of paroxetine in a Japanese population using a population PK approach. METHODS This retrospective study included 179 Japanese patients with major depressive disorder who were being treated with paroxetine. CYP2D6*1, *2, *5, *10, and *41 polymorphisms were observed. A total of 306 steady-state concentrations for paroxetine were collected from the patients. A nonlinear mixed-effects model identified the apparent Michaelis-Menten constant (Km) and the maximum velocity (Vmax) of paroxetine; the covariates included CYP2D6 genotypes, patient age, body weight, sex, and daily paroxetine dose. RESULTS The allele frequencies of CYP2D6*1, *2, *5, *10, and *41 were 39.4, 14.5, 4.5, 41.1, and 0.6%, respectively. There was no poor metabolizer who had two nonfunctional CYP2D6*5 alleles. A one-compartment model showed that the apparent Km value was decreased by 20.6% in patients with the CYP2D6*10/*10 genotype in comparison with the other CYP2D6 genotypes. Female sex also influenced the apparent Km values. No PK parameters were affected by the presence of one CYP2D6*5 allele. CONCLUSION Unexpectedly, elimination was accelerated in individuals with the CYP2D6*10/*10 genotype. Our results show that the presence of one CYP2D6*5 allele or that of any CYP2D6*10 allele may have no major effect on paroxetine PKs in the steady state.
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29
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Yu H, Steeghs N, Kloth JSL, de Wit D, van Hasselt JGC, van Erp NP, Beijnen JH, Schellens JHM, Mathijssen RHJ, Huitema ADR. Integrated semi-physiological pharmacokinetic model for both sunitinib and its active metabolite SU12662. Br J Clin Pharmacol 2016; 79:809-19. [PMID: 25393890 DOI: 10.1111/bcp.12550] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 11/07/2014] [Indexed: 12/31/2022] Open
Abstract
AIMS Previously published pharmacokinetic (PK) models for sunitinib and its active metabolite SU12662 were based on a limited dataset or lacked important elements such as correlations between sunitinib and its metabolite. The current study aimed to develop an improved PK model that circumvented these limitations and to prove the utility of the PK model in treatment optimization in clinical practice. METHODS One thousand two hundred and five plasma samples from 70 cancer patients were collected from three PK studies with sunitinib and SU12662. A semi-physiological PK model for sunitinib and SU12662 was developed incorporating pre-systemic metabolism using non-linear mixed effects modelling (nonmem). Allometric scaling based on body weight was applied. The final model was used for simulation of the PK of different treatment regimens. RESULTS Sunitinib and SU12662 PK were best described by a one and two compartment model, respectively. Introduction of pre-systemic formation of SU12662 strongly improved model fit, compared with solely systemic metabolism. The clearance of sunitinib and SU12662 was estimated at 35.7 (relative standard error (RSE) 5.7%) l h(-1) and 17.1 (RSE 7.4%) l h(-1), respectively for 70 kg patients. Correlation coefficients were estimated between inter-individual variability of both clearances, both volumes of distribution and between clearance and volume of distribution of SU12662 as 0.53, 0.48 and 0.45, respectively. Simulation of the PK model predicted correctly the ratio of patients who did not reach proposed PK targets for efficacy. CONCLUSIONS A semi-physiological PK model for sunitinib and SU12662 in cancer patients was presented including pre-systemic metabolism. The model was superior to previous PK models in many aspects.
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Affiliation(s)
- Huixin Yu
- Department of Pharmacy and Pharmacology, Netherlands Cancer Institute-Antoni van Leeuwenhoek, Amsterdam, The Netherlands
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30
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Caetano D, Piatkov I. Higher than expected clozapine serum level and clozapine/norclozapine ratio due to CYP450 gene polymorphisms. Per Med 2015; 12:555-558. [DOI: 10.2217/pme.15.33] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aims: We investigated a case of the unexpectedly high clozapine/norclozapine serum levels in a non-smoker, female patient. Method: The RFLP genotype method was used for the loss-of-function CYP450 gene polymorphisms detection. Results: The genotype revealed the presence of CYP2D6*41/*41, rs28371725, NM_000106.5:c.985+39G>A and CYP1A2*1/*1D rs35694136, NM_000761.4:c.-1635delT. Conclusion: An appropriate clozapine serum level is required for both optimization of clinical response and avoidance of troublesome, or even life-threatening side effects. Although not the only factor, genetic polymorphisms responsible for the metabolism of clozapine play an important role towards such goals. Pharmacogenetic tests can guide dose adjustment in order to obtain an optimum serum level, which can lead to a better therapeutic response and minimization of harmful side effects.
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Affiliation(s)
- Dorgival Caetano
- Blacktown Mental Health Service, WSLHD, Blacktown, NSW, 2148, Australia
- Blacktown Clinical School & Research Centre, WSLHD, Blacktown, NSW, 2148, Australia
| | - Irina Piatkov
- Blacktown Clinical School & Research Centre, WSLHD, Blacktown, NSW, 2148, Australia
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Cai J, Dai DP, Geng PW, Wang SH, Wang H, Zhan YY, Huang XX, Hu GX, Cai JP. Effects of 22 Novel CYP2D6 Variants Found in the Chinese Population on the Bufuralol and Dextromethorphan MetabolismsIn Vitro. Basic Clin Pharmacol Toxicol 2015; 118:190-9. [PMID: 26310775 DOI: 10.1111/bcpt.12478] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 08/15/2015] [Indexed: 02/01/2023]
Affiliation(s)
- Jie Cai
- The Key Laboratory of Geriatrics; Beijing Hospital & Beijing Institute of Geriatrics; Ministry of Health; Beijing China
- Department of Pharmacology; School of Pharmacy of Wenzhou Medical University; Wenzhou China
- Department of Pharmacy; Traditional Chinese Medical Hospital of Wenling; Wenling China
| | - Da-Peng Dai
- The Key Laboratory of Geriatrics; Beijing Hospital & Beijing Institute of Geriatrics; Ministry of Health; Beijing China
| | - Pei-Wu Geng
- The Laboratory of Clinical Pharmacy; The People's Hospital of Lishui; Lishui China
| | - Shuang-Hu Wang
- The Laboratory of Clinical Pharmacy; The People's Hospital of Lishui; Lishui China
| | - Hao Wang
- Department of Pharmacology; School of Pharmacy of Wenzhou Medical University; Wenzhou China
| | - Yun-Yun Zhan
- Department of Pharmacology; School of Pharmacy of Wenzhou Medical University; Wenzhou China
| | - Xiang-Xin Huang
- Department of Pharmacology; School of Pharmacy of Wenzhou Medical University; Wenzhou China
| | - Guo-Xin Hu
- Department of Pharmacology; School of Pharmacy of Wenzhou Medical University; Wenzhou China
| | - Jian-Ping Cai
- The Key Laboratory of Geriatrics; Beijing Hospital & Beijing Institute of Geriatrics; Ministry of Health; Beijing China
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Tay-Sontheimer J, Shireman LM, Beyer RP, Senn T, Witten D, Pearce RE, Gaedigk A, Gana Fomban CL, Lutz JD, Isoherranen N, Thummel KE, Fiehn O, Leeder JS, Lin YS. Detection of an endogenous urinary biomarker associated with CYP2D6 activity using global metabolomics. Pharmacogenomics 2015; 15:1947-62. [PMID: 25521354 DOI: 10.2217/pgs.14.155] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
AIM We sought to discover endogenous urinary biomarkers of human CYP2D6 activity. PATIENTS & METHODS Healthy pediatric subjects (n = 189) were phenotyped using dextromethorphan and randomized for candidate biomarker selection and validation. Global urinary metabolomics was performed using liquid chromatography quadrupole time-of-flight mass spectrometry. Candidate biomarkers were tested in adults receiving fluoxetine, a CYP2D6 inhibitor. RESULTS A biomarker, M1 (m/z 444.3102) was correlated with CYP2D6 activity in both the pediatric training and validation sets. Poor metabolizers had undetectable levels of M1, whereas it was present in subjects with other phenotypes. In adult subjects, a 9.56-fold decrease in M1 abundance was observed during CYP2D6 inhibition. CONCLUSION Identification and validation of M1 may provide a noninvasive means of CYP2D6 phenotyping.
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33
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Hertz DL, Snavely AC, McLeod HL, Walko CM, Ibrahim JG, Anderson S, Weck KE, Magrinat G, Olajide O, Moore S, Raab R, Carrizosa DR, Corso S, Schwartz G, Peppercorn JM, Evans JP, Jones DR, Desta Z, Flockhart DA, Carey LA, Irvin WJ. In vivo assessment of the metabolic activity of CYP2D6 diplotypes and alleles. Br J Clin Pharmacol 2015; 80:1122-30. [PMID: 25907378 DOI: 10.1111/bcp.12665] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 04/07/2015] [Accepted: 04/11/2015] [Indexed: 01/13/2023] Open
Abstract
AIMS A prospectively enrolled patient cohort was used to assess whether the prediction of CYP2D6 phenotype activity from genotype data could be improved by reclassification of diplotypes or alleles. METHODS Three hundred and fifty-five patients receiving tamoxifen 20 mg were genotyped for CYP2D6 and tamoxifen metabolite concentrations were measured. The endoxifen : N-desmethly-tamoxifen metabolic ratio, as a surrogate of CYP2D6 activity, was compared across four diplotypes (EM/IM, EM/PM, IM/IM, IM/PM) that are typically collapsed into an intermediate metabolizer (IM) phenotype. The relative metabolic activity of each allele type (UM, EM, IM, and PM) and each EM and IM allele was estimated for comparison with the activity scores typically assigned, 2, 1, 0.5 and 0, respectively. RESULTS Each of the four IM diplotypes have distinct CYP2D6 activity from each other and from the EM and PM phenotype groups (each P < 0.05). Setting the activity of an EM allele at 1.0, the relative activities of a UM, IM and PM allele were 0.85, 0.67 and 0.52, respectively. The activity of the EM alleles were statistically different (P < 0.0001), with the CYP2D6*2 allele (scaled activity = 0.63) closer in activity to an IM than an EM allele. The activity of the IM alleles were also statistically different (P = 0.014). CONCLUSION The current systems for translating CYP2D6 genotype into phenotype are not optimally calibrated, particularly in regards to IM diplotypes and the *2 allele. Additional research is needed to improve the prediction of CYP2D6 activity from genetic data for individualized dosing of CYP2D6 dependent drugs.
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Affiliation(s)
| | - Anna C Snavely
- RTI International, Research Triangle Park, NC, 27709-2194, USA
| | | | | | - Joseph G Ibrahim
- University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Steven Anderson
- Laboratory Corporation of America, Burlington, NC, 27215, USA
| | - Karen E Weck
- University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Gustav Magrinat
- Moses Cone Health Cancer Center, Greensboro, NC, 27401-1020, USA
| | | | - Susan Moore
- Rex Hematology Oncology Associates, Raleigh, NC, 27607, USA
| | - Rachel Raab
- Brody School of Medicine at East Carolina University, Greenville, NC, 27834, USA
| | | | - Steven Corso
- Palmetto Hematology Oncology, Spartanburg, SC, 29303, USA
| | - Garry Schwartz
- Levine Cancer Institute Concord, Concord, NC, 28025, USA
| | | | - James P Evans
- University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | | | | | | | - Lisa A Carey
- University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - William J Irvin
- University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.,Bon Secours Cancer Institute, Richmond, VA, 23230, USA
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34
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ter Heine R, Binkhorst L, de Graan AJM, de Bruijn P, Beijnen JH, Mathijssen RHJ, Huitema ADR. Population pharmacokinetic modelling to assess the impact of CYP2D6 and CYP3A metabolic phenotypes on the pharmacokinetics of tamoxifen and endoxifen. Br J Clin Pharmacol 2015; 78:572-86. [PMID: 24697814 DOI: 10.1111/bcp.12388] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 03/25/2014] [Indexed: 12/12/2022] Open
Abstract
AIMS Tamoxifen is considered a pro-drug of its active metabolite endoxifen. The major metabolic enzymes involved in endoxifen formation are CYP2D6 and CYP3A. There is considerable evidence that variability in activity of these enzymes influences endoxifen exposure and thereby may influence the clinical outcome of tamoxifen treatment. We aimed to quantify the impact of metabolic phenotype on the pharmacokinetics of tamoxifen and endoxifen. METHODS We assessed the CYP2D6 and CYP3A metabolic phenotypes in 40 breast cancer patients on tamoxifen treatment with a single dose of dextromethorphan as a dual phenotypic probe for CYP2D6 and CYP3A. The pharmacokinetics of dextromethorphan, tamoxifen and their relevant metabolites were analyzed using non-linear mixed effects modelling. RESULTS Population pharmacokinetic models were developed for dextromethorphan, tamoxifen and their metabolites. In the final model for tamoxifen, the dextromethorphan derived metabolic phenotypes for CYP2D6 as well as CYP3A significantly (P < 0.0001) explained 54% of the observed variability in endoxifen formation (inter-individual variability reduced from 55% to 25%). CONCLUSIONS We have shown that not only CYP2D6, but also CYP3A enzyme activity influences the tamoxifen to endoxifen conversion in breast cancer patients. Our developed model may be used to assess separately the impact of CYP2D6 and CYP3A mediated drug-drug interactions with tamoxifen without the necessity of administering this anti-oestrogenic drug and to support Bayesian guided therapeutic drug monitoring of tamoxifen in routine clinical practice.
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Affiliation(s)
- Rob ter Heine
- Department of Clinical Pharmacy, Meander Medical Center, Amersfoort, The Netherlands
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35
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Cytochrome P450 2D6*10 genotype affects the pharmacokinetics of dimemorfan in healthy Chinese subjects. Eur J Drug Metab Pharmacokinet 2014; 40:427-33. [PMID: 25159483 DOI: 10.1007/s13318-014-0221-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 08/16/2014] [Indexed: 10/24/2022]
Abstract
This study aimed to investigate the effects of cytochrome P450 2D6*10 (100C > T, rs1065852) genotype on the pharmacokinetics of dimemorfan in healthy Chinese subjects. Data were evaluated from 24 subjects in two pharmacokinetic studies who received an oral dose of 40 mg of dimemorfan syrup (n = 12) or dimemorfan tablet (n = 12) after providing written informed consent and being divided into three groups: subjects with CYP2D6*10 CC (n = 5), CYP2D6*10 CT (n = 11) and CYP2D6*10 TT (n = 8). CC homozygotes and CT heterozygotes were defined to be C allele carriers. The CYP2D6*10 was genotyped by polymerase chain reaction-restriction fragment length polymorphism. Dimemorfan was measured by LC-MS/MS. There was significant difference in C max, AUC0-t , AUC0-inf, V z , and CL values of dimemorfan observed among the three CYP2D6*10 genotype groups (GLM, (a) P < 0.05, co-dominant model). CYP2D6*10 under the recessive model (CC + TC vs TT) was significantly associated with pharmacokinetics of dimemorfan ((c) P < 0.05). The C max values were significantly higher in subjects with CYP2D6*10 TT (8.06 ± 4.43 ng/mL) than CYP2D6*10 CC (3.41 ± 2.79 ng/mL), CYP2D6*10 CT (3.11 ± 2.47 ng/mL), so was AUC0-inf. V z /F and CL/F of subjects with CYP2D6*10 TT homozygotes were the lowest. We demonstrated that cytochrome P450 2D6*10 (100C > T, rs1065852) polymorphism can affect the pharmacokinetics of dimemorfan in humans, not dosage forms.
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Abduljalil K, Cain T, Humphries H, Rostami-Hodjegan A. Deciding on Success Criteria for Predictability of Pharmacokinetic Parameters from In Vitro Studies: An Analysis Based on In Vivo Observations. Drug Metab Dispos 2014; 42:1478-84. [DOI: 10.1124/dmd.114.058099] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Wang D, Poi MJ, Sun X, Gaedigk A, Leeder JS, Sadee W. Common CYP2D6 polymorphisms affecting alternative splicing and transcription: long-range haplotypes with two regulatory variants modulate CYP2D6 activity. Hum Mol Genet 2014; 23:268-78. [PMID: 23985325 PMCID: PMC3857955 DOI: 10.1093/hmg/ddt417] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 08/01/2013] [Accepted: 08/22/2013] [Indexed: 01/20/2023] Open
Abstract
Cytochrome P450 2D6 (CYP2D6) is involved in the metabolism of 25% of clinically used drugs. Genetic polymorphisms cause substantial variation in CYP2D6 activity and serve as biomarkers guiding drug therapy. However, genotype-phenotype relationships remain ambiguous except for poor metabolizers carrying null alleles, suggesting the presence of yet unknown genetic variants. Searching for regulatory CYP2D6 polymorphisms, we find that a SNP defining the CYP2D6*2 allele, rs16947 [R296C, 17-60% minor allele frequency (MAF)], previously thought to convey normal activity, alters exon 6 splicing, thereby reducing CYP2D6 expression at least 2-fold. In addition, two completely linked SNPs (rs5758550/rs133333, MAF 13-42%) increase CYP2D6 transcription more than 2-fold, located in a distant downstream enhancer region (>100 kb) that interacts with the CYP2D6 promoter. In high linkage disequilibrium (LD) with each other, rs16947 and the enhancer SNPs form haplotypes that affect CYP2D6 enzyme activity in vivo. In a pediatric cohort of 164 individuals, rs16947 alone (minor haplotype frequency 28%) was associated with reduced CYP2D6 metabolic activity (measured as dextromethorphan/metabolite ratios), whereas rs5758550/rs133333 alone (frequency 3%) resulted in increased CYP2D6 activity, while haplotypes containing both rs16947 and rs5758550/rs133333 were similar to the wild-type. Other alleles used in biomarker panels carrying these variants such as CYP2D6*41 require re-evaluation of independent effects on CYP2D6 activity. The occurrence of two regulatory variants of high frequency and in high LD, residing on a long haplotype, highlights the importance of gene architecture, likely shaped by evolutionary selection pressures, in determining activity of encoded proteins.
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Affiliation(s)
- Danxin Wang
- Program in Pharmacogenomics, Department of Pharmacology, School of Medicine and
| | - Ming J. Poi
- Department of Pharmacy, The Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, The Ohio State University, Columbus, OH, USA and
| | - Xiaochun Sun
- Program in Pharmacogenomics, Department of Pharmacology, School of Medicine and
| | - Andrea Gaedigk
- Division of Clinical Pharmacology and Therapeutic Innovation, Children's Mercy Hospital, Kansas City, MO, USA
| | - J. Steven Leeder
- Division of Clinical Pharmacology and Therapeutic Innovation, Children's Mercy Hospital, Kansas City, MO, USA
| | - Wolfgang Sadee
- Program in Pharmacogenomics, Department of Pharmacology, School of Medicine and
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Ding Y, Huang K, Chen L, Yang J, Xu WY, Xu XJ, Duan R, Zhang J, He Q. Simultaneous quantitative analysis of dextromethorphan, dextrorphan and chlorphenamine in human plasma by liquid chromatography-electrospray tandem mass spectrometry. Biomed Chromatogr 2013; 28:446-52. [PMID: 24254834 DOI: 10.1002/bmc.3054] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Revised: 08/29/2013] [Accepted: 09/03/2013] [Indexed: 11/10/2022]
Affiliation(s)
- Ying Ding
- Drug Clinical Trial Institution, Wuxi People's Hospital; Nanjing Medical University; 299 Qingyang Road Wuxi 214023 People's Republic of China
| | - Kai Huang
- Drug Clinical Trial Institution, Wuxi People's Hospital; Nanjing Medical University; 299 Qingyang Road Wuxi 214023 People's Republic of China
| | - Lan Chen
- Drug Clinical Trial Institution, Wuxi People's Hospital; Nanjing Medical University; 299 Qingyang Road Wuxi 214023 People's Republic of China
| | - Jie Yang
- Drug Clinical Trial Institution, Wuxi People's Hospital; Nanjing Medical University; 299 Qingyang Road Wuxi 214023 People's Republic of China
| | - Wen-Yan Xu
- Drug Clinical Trial Institution, Wuxi People's Hospital; Nanjing Medical University; 299 Qingyang Road Wuxi 214023 People's Republic of China
| | - Xue-Jiao Xu
- Drug Clinical Trial Institution, Wuxi People's Hospital; Nanjing Medical University; 299 Qingyang Road Wuxi 214023 People's Republic of China
| | - Ru Duan
- Drug Clinical Trial Institution, Wuxi People's Hospital; Nanjing Medical University; 299 Qingyang Road Wuxi 214023 People's Republic of China
| | - Jing Zhang
- Drug Clinical Trial Institution, Wuxi People's Hospital; Nanjing Medical University; 299 Qingyang Road Wuxi 214023 People's Republic of China
| | - Qing He
- Drug Clinical Trial Institution, Wuxi People's Hospital; Nanjing Medical University; 299 Qingyang Road Wuxi 214023 People's Republic of China
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Abstract
Cytochrome P450 2D6 (CYP2D6) plays an important role in the metabolism and bioactivation of about 25% of clinically used drugs including many antidepressants, antipsychotics and opioids. CYP2D6 activity is highly variably ranging from no activity in so-called poor metabolizers to ultrarapid metabolism at the other end of the extreme of the activity distribution. A large portion of this variability can be explained by the highly polymorphic nature of the CYP2D6 gene locus for which > 100 variants and subvariants identified to date. Allele frequencies vary markedly between ethnic groups; some have exclusively or predominantly only been observed in certain populations. Pharmacogenetic testing holds the promise of individualizing drug therapy by identifying patients with CYP2D6 diplotypes that puts them at an increased risk of experiencing dose-related adverse events or therapeutic failure. Inferring a patient's CYP2D6 metabolic capacity, or phenotype, however, is a challenging task due to the complexity of the CYP2D6 gene locus. Allelic variation includes SNPs, small insertions and deletions, gene copy number variation and rearrangements with CYP2D7, a highly related non-functional gene. This review provides a summary of the intricacies of CYP2D6 variation and genotype analysis, knowledge that is invaluable for the translation of genotype into clinically useful information.
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Affiliation(s)
- Andrea Gaedigk
- Children's Mercy Hospital and Clinics, Division of Clinical Pharmacology and Innovative Therapeutics , Kansas City, Missouri , USA
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Montané Jaime LK, Lalla A, Steimer W, Gaedigk A. Characterization of the CYP2D6 gene locus and metabolic activity in Indo- and Afro-Trinidadians: discovery of novel allelic variants. Pharmacogenomics 2013; 14:261-76. [PMID: 23394389 DOI: 10.2217/pgs.12.207] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The highly polymorphic CYP2D6 gene has extensively been studied in many populations, but there is a void of knowledge regarding CYP2D6 pharmacogenetics and activity in populations with unique ancestries and admixture, such as those residing in Trinidad and Tobago. MATERIALS & METHODS 167 healthy Indo- and 103 Afro-Trinidadians were phenotyped with dextromethorphan and extensively genotyped. Gene resequencing was performed to resolve cases with genotype/phenotype discordance. RESULTS CYP2D6 activity did not differ between the Indo-Trinidadians and Afro-Trinidadians. Poor metabolizers were, however, more frequent in the Indo-Trinidadians (4.19 vs 1.94%), and unique allele frequency patterns were observed. Two novel nonfunctional allelic variants were found among the Indo-Trinidadians in two discordant cases. CYP2D6*100 is characterized by a single nucleotide deletion and CYP2D6*101 by a 19-bp deletion; both cause frameshifts. CONCLUSION Our study underscores the importance of thoroughly characterizing the genetic make up of unique populations when considering pharmacogenetic testing for individualized therapy.
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Affiliation(s)
- Lazara Karelia Montané Jaime
- Pharmacology Unit, Department of Paraclinical Sciences, Faculty of Medical Sciences, The University of The West Indies, St Augustine, Trinidad & Tobago.
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CYP2D6 genotype affects age-related decline in flecainide clearance: a population pharmacokinetic analysis. Pharmacogenet Genomics 2013; 22:777-83. [PMID: 22941032 DOI: 10.1097/fpc.0b013e3283588fe5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To investigate the association between age-related decline in flecainide clearance and CYP2D6 genotype, we conducted a population pharmacokinetic analysis of flecainide using routine therapeutic drug monitoring data. METHODS Population pharmacokinetic analysis was performed on retrospective data from 163 genotyped patients treated with oral flecainide for supraventricular tachyarrhythmias. The CYP2D6 genotype was categorized as CYP2D6 homozygous extensive metabolizers (hom-EMs; n=57), heterozygous extensive metabolizers (het-EMs; n=79), and intermediate metabolizers and poor metabolizers (IMs/PMs; n=27). RESULTS Population pharmacokinetic analysis revealed that estimated glomerular filtration rate, body weight, female sex, and aging were important factors for estimating flecainide clearance. The metabolic clearance was decreased age dependently in a curvilinear fashion, where the lower clearance was observed in greater than 60 years for het-EMs and greater than 55 years for IMs/PMs. The reduction in metabolic clearance in elderly (70 years) patients compared with middle-aged (52 years) patients was different among the CYP2D6 genotype groups: 22.1 and 49.5% in CYP2D6 het-EMs and IMs/PMs, respectively, and no change in hom-EMs. A 11.4% reduction in estimated glomerular filtration rate in elderly patients compared with middle-aged patients corresponded to 6.1% decline in flecainide clearance. Overall, the age-related decline in flecainide clearance was 6.1% in hom-EMs, 16.3% in het-EMs, and 28.9% in IMs/PMs groups. CONCLUSION This study suggests that CYP2D6 genotype is a determinant factor of age-related decline in flecainide clearance.
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Ke AB, Nallani SC, Zhao P, Rostami-Hodjegan A, Isoherranen N, Unadkat JD. A physiologically based pharmacokinetic model to predict disposition of CYP2D6 and CYP1A2 metabolized drugs in pregnant women. Drug Metab Dispos 2013; 41:801-13. [PMID: 23355638 DOI: 10.1124/dmd.112.050161] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Conducting pharmacokinetic (PK) studies in pregnant women is challenging. Therefore, we asked if a physiologically based pharmacokinetic (PBPK) model could be used to evaluate different dosing regimens for pregnant women. We refined and verified our previously published pregnancy PBPK model by incorporating cytochrome P450 CYP1A2 suppression (based on caffeine PK) and CYP2D6 induction (based on metoprolol PK) into the model. This model accounts for gestational age-dependent changes in maternal physiology and hepatic CYP3A activity. For verification, the disposition of CYP1A2-metabolized drug theophylline (THEO) and CYP2D6-metabolized drugs paroxetine (PAR), dextromethorphan (DEX), and clonidine (CLO) during pregnancy was predicted. Our PBPK model successfully predicted THEO disposition during the third trimester (T3). Predicted mean postpartum to third trimester (PP:T3) ratios of THEO area under the curve (AUC), maximum plasma concentration, and minimum plasma concentration were 0.76, 0.95, and 0.66 versus observed values 0.75, 0.89, and 0.72, respectively. The predicted mean PAR steady-state plasma concentration (Css) ratio (PP:T3) was 7.1 versus the observed value 3.7. Predicted mean DEX urinary ratio (UR) (PP:T3) was 2.9 versus the observed value 1.9. Predicted mean CLO AUC ratio (PP:T3) was 2.2 versus the observed value 1.7. Sensitivity analysis suggested that a 100% induction of CYP2D6 during T3 was required to recover the observed PP:T3 ratios of PAR Css, DEX UR, and CLO AUC. Based on these data, it is prudent to conclude that the magnitude of hepatic CYP2D6 induction during T3 ranges from 100 to 200%. Our PBPK model can predict the disposition of CYP1A2, 2D6, and 3A drugs during pregnancy.
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Affiliation(s)
- Alice Ban Ke
- Department of Pharmaceutics, University of Washington, Box 357610, Seattle, WA 98195, USA
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Abduljalil K, Furness P, Johnson TN, Rostami-Hodjegan A, Soltani H. Anatomical, Physiological and Metabolic Changes with Gestational Age during Normal Pregnancy. Clin Pharmacokinet 2012; 51:365-96. [DOI: 10.2165/11597440-000000000-00000] [Citation(s) in RCA: 220] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Gaedigk A, Hernandez J, García-Solaesa V, Sánchez S, Isidoro-García M. Detection and characterization of the CYP2D6*9x2 gene duplication in two Spanish populations: resolution of AmpliChip CYP450 test no-calls. Pharmacogenomics 2012; 12:1617-22. [PMID: 22044417 DOI: 10.2217/pgs.11.107] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND CYP2D6 is a major drug-metabolizing enzyme. Polymorphic variation includes copy number variants such as gene deletions, duplications and multiplications of functional and nonfunctional gene units. In this article we describe the first systematic characterization of a CYP2D6*9x2 gene duplication. CYP2D6*9 is an allelic variant conferring reduced enzymatic activity. This novel gene duplication was discovered in two unrelated Spanish psychiatric patients. Both subjects were initially tested with the AmpliChip CYP450 test, which indicated the presence of a duplication and the CYP2D6*9 allele, but did not make a genotype call. The goal of the study was to resolve this issue by characterizing the CYP2D6 gene locus in these patients. MATERIALS & METHODS Both individuals and one offspring were regenotyped using our own CYP2D6 genotyping strategy employing long-range PCR and TaqMan-based SNP detection. In addition, gene resequencing and genotyping of duplication-specific long-range PCR products and quantitative gene copy number analysis was applied. RESULTS The duplication was mapped to the CYP2D6*9 allele and copy number analysis determined a CYP2D6*9x2 gene duplication in all three individuals. Because CYP2D6*9x2 is not recognized by the AmpliChip CYP450 test, this structural arrangement was responsible for the 'no call' on the AmpliChip CYP450 test report. CONCLUSION The full characterization of this allele will aid in the interpretation of AmpliChip CYP450 test results for clinical and research applications. Original submitted 8 June 2011; Revision submitted 18 July 2011.
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Affiliation(s)
- Andrea Gaedigk
- Laboratori de Referencia de Catalunya, El Prat de Llobregat, Barcelona, Spain.
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Teh LK, Bertilsson L. Pharmacogenomics of CYP2D6: molecular genetics, interethnic differences and clinical importance. Drug Metab Pharmacokinet 2011; 27:55-67. [PMID: 22185816 DOI: 10.2133/dmpk.dmpk-11-rv-121] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
CYP2D6 has received intense attention since the beginning of the pharmacogenetic era in the 1970s. This is because of its involvement in the metabolism of more than 25% of the marketed drugs, the large geographical and inter-ethnic differences in the genetic polymorphism and possible drug-induced toxicity. Many interesting reviews have been published on CYP2D6 and this review aims to reinstate the importance of the genetic polymorphism of CYP2D6 in different populations as well as some clinical implications and important drug interactions.
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Affiliation(s)
- Lay Kek Teh
- Pharmacogenomics Centre PROMISE, Faculty of Pharmacy, Universiti Teknologi MARA, Selangor DE, Malaysia.
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Lutz JD, Isoherranen N. Prediction of relative in vivo metabolite exposure from in vitro data using two model drugs: dextromethorphan and omeprazole. Drug Metab Dispos 2011; 40:159-68. [PMID: 22010218 DOI: 10.1124/dmd.111.042200] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Metabolites can have pharmacological or toxicological effects, inhibit metabolic enzymes, and be used as probes of drug-drug interactions or specific cytochrome P450 (P450) phenotypes. Thus, better understanding and prediction methods are needed to characterize metabolite exposures in vivo. This study aimed to test whether in vitro data could be used to predict and rationalize in vivo metabolite exposures using two model drugs and P450 probes: dextromethorphan and omeprazole with their primary metabolites dextrorphan, 5-hydroxyomeprazole (5OH-omeprazole), and omeprazole sulfone. Relative metabolite exposures were predicted using metabolite formation and elimination clearances. For dextrorphan, the formation clearances of dextrorphan glucuronide and 3-hydroxymorphinan from dextrorphan in human liver microsomes were used to predict metabolite (dextrorphan) clearance. For 5OH-omeprazole and omeprazole sulfone, the depletion rates of the metabolites in human hepatocytes were used to predict metabolite clearance. Dextrorphan/dextromethorphan in vivo metabolite/parent area under the plasma concentration versus time curve ratio (AUC(m)/AUC(p)) was overpredicted by 2.1-fold, whereas 5OH-omeprazole/omeprazole and omeprazole sulfone/omeprazole were predicted within 0.75- and 1.1-fold, respectively. The effect of inhibition or induction of the metabolite's formation and elimination on the AUC(m)/AUC(p) ratio was simulated. The simulations showed that unless metabolite clearance pathways are characterized, interpretation of the metabolic ratios is exceedingly difficult. This study shows that relative in vivo metabolite exposure can be predicted from in vitro data and characterization of secondary metabolism of probe metabolites is critical for interpretation of phenotypic data.
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Affiliation(s)
- Justin D Lutz
- School of Pharmacy, Department of Pharmaceutics, University of Washington, Seattle, WA 98195-7610, USA
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Black JL, Walker DL, O'Kane DJ, Harmandayan M. Frequency of undetected CYP2D6 hybrid genes in clinical samples: impact on phenotype prediction. Drug Metab Dispos 2011; 40:111-9. [PMID: 22004686 DOI: 10.1124/dmd.111.040832] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cytochrome P450 2D6 (CYP2D6) is highly polymorphic. CYP2D6-2D7 hybrid genes can be present in samples containing CYP2D6*4 and CYP2D6*10 alleles. CYP2D7-2D6 hybrid genes can be present in samples with duplication signals and in samples with homozygous genotyping results. The frequency of hybrid genes in clinical samples is unknown. We evaluated 1390 samples for undetected hybrid genes by polymerase chain reaction (PCR) amplification, PCR fragment analysis, TaqMan copy number assays, DNA sequencing, and allele-specific primer extension assay. Of 508 CYP2D6*4-containing samples, 109 (21.5%) harbored CYP2D6*68 + *4-like, whereas 9 (1.8%) harbored CYP2D6*4N + *4-like. Of 209 CYP2D6*10-containing samples, 44 (21.1%) were found to have CYP2D6*36 + *10. Of 332 homozygous samples, 4 (1.2%) harbored a single CYP2D7-2D6 hybrid, and of 341 samples with duplication signals, 25 (7.3%) harbored an undetected CYP2D7-2D6 hybrid. Phenotype before and after accurate genotyping was predicted using a method in clinical use. The presence of hybrid genes had no effect on the phenotype prediction of CYP2D6*4- and CYP2D6*10-containing samples. Four of four (100%) homozygous samples containing a CYP2D7-2D6 gene had a change in predicted phenotype, and 23 of 25 (92%) samples with a duplication signal and a CYP2D7-2D6 gene had a change in predicted phenotype. Four novel genes were identified (CYP2D6*13A1 variants 1 and 2, CYP2D6*13G1, and CYP2D6*13G2), and two novel hybrid tandem structures consisting of CYP2D6*13B + *68×2 + *4-like and CYP2D6*13A1 variant 2 + *1×N were observed.
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Affiliation(s)
- John Logan Black
- Department of Laboratory Medicine and Pathology, Mayo Clinic 200 1st Street SW, Rochester, Minnesota, NM 55902, USA.
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Genotype-Based Quantitative Prediction of Drug Exposure for Drugs Metabolized by CYP2D6. Clin Pharmacol Ther 2011; 90:582-7. [DOI: 10.1038/clpt.2011.147] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Sehrt D, Meineke I, Tzvetkov M, Gültepe S, Brockmöller J. Carvedilol pharmacokinetics and pharmacodynamics in relation to CYP2D6 and ADRB pharmacogenetics. Pharmacogenomics 2011; 12:783-95. [PMID: 21599570 DOI: 10.2217/pgs.11.20] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIMS Carvedilol is an effective treatment in hypertension and chronic heart failure. The medical impact of polymorphisms in CYP2D6 and in the β-adrenergic receptors ADRB1 and ADRB2 on the pharmacokinetics and pharmacodynamics of carvedilol is controversial. METHODS After carvedilol 25 mg was administered to 110 volunteers, concentrations were enantioselectively quantified and effects on resting and exercise-induced heart rate and blood pressure were analyzed using population pharmacokinetic, pharmacodynamic and pharmacogenetic modeling. RESULTS There were significant CYP2D6 allele-specific differences in carvedilol pharmacokinetics, but the CYP2D6 genotype had no effect on heart rate, blood pressure or adverse effects. ADRB1 Gly49 was associated with higher baseline heart rates and with greater carvedilol effects on exercise heart rates. Carriers of ADRB2 Gln27 had greater reduction in resting blood pressure by carvedilol compared with Glu27. CONCLUSION Carvedilol is a drug where CYP2D6-related pharmacokinetic variation is apparently not carried forward into pharmacodynamic variation. Although current knowledge does not allow utilizing ADRB1 and ADRB2 genotypes for clinical treatment decisions, our data should stimulate further research on the impact of these genotypes in health and disease.
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Affiliation(s)
- Daniel Sehrt
- University Medicine Göttingen, Department of Clinical Pharmacology, Robert-Koch-Str. 40, D-37075 Göttingen, Germany
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