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Untereiner AA, Pavlidou A, Druzhyna N, Papapetropoulos A, Hellmich MR, Szabo C. Drug resistance induces the upregulation of H 2S-producing enzymes in HCT116 colon cancer cells. Biochem Pharmacol 2017; 149:174-185. [PMID: 29061341 DOI: 10.1016/j.bcp.2017.10.007] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Accepted: 10/18/2017] [Indexed: 01/01/2023]
Abstract
Hydrogen sulfide (H2S) production in colon cancer cells supports cellular bioenergetics and proliferation. The aim of the present study was to investigate the alterations in H2S homeostasis during the development of resistance to 5-fluorouracil (5-FU), a commonly used chemotherapeutic agent. A 5-FU-resistant HCT116 human colon cancer cell line was established by serial passage in the presence of increasing 5-FU concentrations. The 5-FU-resistant cells also demonstrated a partial resistance to an unrelated chemotherapeutic agent, oxaliplatin. Compared to parental cells, the 5-FU-resistant cells rely more on oxidative phosphorylation than glycolysis for bioenergetic function. There was a significant increase in the expression of the drug-metabolizing cytochrome P450 enzymes CYP1A2 and CYP2A6 in 5-FU-resistant cells. The CYP450 inhibitor phenylpyrrole enhanced 5-FU-induced cytotoxicity in 5-FU-resistant cells. Two major H2S-generating enzymes, cystathionine-β-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase (3-MST) were upregulated in the 5-FU-resistant cells. 5-FU-resistant cells exhibited decreased sensitivity to the CBS inhibitor aminooxyacetate (AOAA) in terms of suppression of cell viability, inhibition of cell proliferation and inhibition of oxidative phosphorylation. However, 5FU-resistant cells remained sensitive to the antiproliferative effect of benserazide (a recently identified, potentially repurposable CBS inhibitor). Taken together, the current data suggest that 5-FU resistance in HCT116 cells is associated with the upregulation of drug-metabolizing enzymes and an enhancement of endogenous H2S production. The anticancer effect of prototypical H2S biosynthesis inhibitor AOAA is impaired in 5-FU-resistant cells, but benserazide remains efficacious. Pharmacological approaches aimed at restoring the sensitivity of 5-FU-resistant cells to chemotherapeutic agents may be useful in the formulation of novel therapeutic strategies against colorectal cancer.
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Affiliation(s)
- Ashley A Untereiner
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Athanasia Pavlidou
- Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Greece
| | - Nadiya Druzhyna
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Andreas Papapetropoulos
- Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Greece; Clinical, Experimental Surgery and Translational Research Center, Biomedical Research Foundation of the Academy of Athens, Greece
| | - Mark R Hellmich
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Csaba Szabo
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX 77555, USA.
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Huang W, Nakano M, Sager J, Ragueneau-Majlessi I, Isoherranen N. Physiologically Based Pharmacokinetic Model of the CYP2D6 Probe Atomoxetine: Extrapolation to Special Populations and Drug-Drug Interactions. Drug Metab Dispos 2017; 45:1156-1165. [PMID: 28860113 DOI: 10.1124/dmd.117.076455] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 08/28/2017] [Indexed: 01/18/2023] Open
Abstract
Physiologically based pharmacokinetic (PBPK) modeling of drug disposition and drug-drug interactions (DDIs) has become a key component of drug development. PBPK modeling has also been considered as an approach to predict drug disposition in special populations. However, whether models developed and validated in healthy populations can be extrapolated to special populations is not well established. The goal of this study was to determine whether a drug-specific PBPK model validated using healthy populations could be used to predict drug disposition in specific populations and in organ impairment patients. A full PBPK model of atomoxetine was developed using a training set of pharmacokinetic (PK) data from CYP2D6 genotyped individuals. The model was validated using drug-specific acceptance criteria and a test set of 14 healthy subject PK studies. Population PBPK models were then challenged by simulating the effects of ethnicity, DDIs, pediatrics, and renal and hepatic impairment on atomoxetine PK. Atomoxetine disposition was successfully predicted in 100% of healthy subject studies, 88% of studies in Asians, 79% of DDI studies, and 100% of pediatric studies. However, the atomoxetine area under the plasma concentration versus time curve (AUC) was overpredicted by 3- to 4-fold in end stage renal disease and hepatic impairment. The results show that validated PBPK models can be extrapolated to different ethnicities, DDIs, and pediatrics but not to renal and hepatic impairment patients, likely due to incomplete understanding of the physiologic changes in these conditions. These results show that systematic modeling efforts can be used to further refine population models to improve the predictive value in this area.
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Affiliation(s)
- Weize Huang
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington
| | - Mariko Nakano
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington
| | - Jennifer Sager
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington
| | | | - Nina Isoherranen
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington
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Schroth W, Winter S, Mürdter T, Schaeffeler E, Eccles D, Eccles B, Chowbay B, Khor CC, Tfayli A, Zgheib NK, Eichelbaum M, Schwab M, Brauch H. Improved Prediction of Endoxifen Metabolism by CYP2D6 Genotype in Breast Cancer Patients Treated with Tamoxifen. Front Pharmacol 2017; 8:582. [PMID: 28955222 PMCID: PMC5609540 DOI: 10.3389/fphar.2017.00582] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 08/11/2017] [Indexed: 12/13/2022] Open
Abstract
Purpose: Prediction of impaired tamoxifen (TAM) to endoxifen metabolism may be relevant to improve breast cancer treatment, e.g., via TAM dose increase. The polymorphic cytochrome P450 2D6 (CYP2D6) strongly determines an individual's capacity for endoxifen formation, however, CYP2D6 phenotype assignments inferred from genotype widely differ between studies. Thus, we modeled plasma endoxifen predictability depending on variable CYP2D6 genotype groupings. Methods: CYP2D6 diplotype and metabolite plasma concentrations were assessed in 908 pre- and post-menopausal estrogen receptor (ER)-positive, TAM treated early breast cancer patients of Caucasian (N = 678), Middle-Eastern Arab (N = 77), and Asian (N = 153) origin. Robust coefficients of determination (R2) were estimated for endoxifen (E) or metabolic ratio endoxifen/desmethyl-TAM (E/DMT) as dependent and different CYP2D6 phenotype assignments as independent variables. Allele activity scores (ASs) were modified with respect to a reduced ∗10 allele activity. Predictability of endoxifen plasma concentrations above the clinical threshold of 5.9 ng/mL was investigated by receiver operating characteristic (ROC) analysis. Results: CYP2D6 diplotypes (N = 898) were strongly associated with E and E/DMT independent of age (P < 10-15). Across all ethnicities, 68-82% inter-patient variability of E/DMT was explained by CYP2D6 diplotype, while plasma endoxifen was predictable by 39-58%. The previously used codeine specific phenotype classification showed worse prediction for both endpoints particularly in Asians (median R2< 20%; P < 10-9). Downgrading of ∗10 activity slightly improved the explanatory value of metabolizer phenotype (P < 0.002). Endoxifen plasma concentrations above the clinical threshold of 5.9 ng/mL were achieved in 82.3% of patients and were predictable (96% sensitivity, 57% specificity) by CYP2D6 diplotypes with AS > 0.5, i.e., omitting PM/PM and PM/IM patients. Conclusion: The CYP2D6 explanatory power for active drug level assessment is maximized by TAM-specific phenotype assignments while a genotype cutoff that separates PM/PM and PM/IM from the remaining patients may improve clinical benefit via increased endoxifen concentrations.
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Affiliation(s)
- Werner Schroth
- Dr. Margarete Fischer-Bosch-Institute of Clinical PharmacologyStuttgart, Germany
- Department of Clinical Pharmacology, University of TübingenTübingen, Germany
| | - Stefan Winter
- Dr. Margarete Fischer-Bosch-Institute of Clinical PharmacologyStuttgart, Germany
- Department of Clinical Pharmacology, University of TübingenTübingen, Germany
| | - Thomas Mürdter
- Dr. Margarete Fischer-Bosch-Institute of Clinical PharmacologyStuttgart, Germany
- Department of Clinical Pharmacology, University of TübingenTübingen, Germany
| | - Elke Schaeffeler
- Dr. Margarete Fischer-Bosch-Institute of Clinical PharmacologyStuttgart, Germany
- Department of Clinical Pharmacology, University of TübingenTübingen, Germany
| | - Diana Eccles
- Cancer Sciences Academic Unit and University of Southampton Clinical Trials Unit, Faculty of Medicine, University of SouthamptonSouthampton, United Kingdom
| | | | - Balram Chowbay
- Laboratory of Clinical Pharmacology, Division of Medical Sciences, National Cancer CentreSingapore, Singapore
- Clinical Pharmacology, SingHealthSingapore, Singapore
- Office of Clinical Sciences, Duke-NUS Medical SchoolSingapore, Singapore
| | - Chiea C. Khor
- Division of Human Genetics, Genome Institute of SingaporeSingapore, Singapore
- Singapore Eye Research InstituteSingapore, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of SingaporeSingapore, Singapore
| | - Arafat Tfayli
- Hematology-Oncology Division, Department of Internal Medicine, Faculty of Medicine, American University of BeirutBeirut, Lebanon
| | - Nathalie K. Zgheib
- Department of Pharmacology and Toxicology, Faculty of Medicine, American University of BeirutBeirut, Lebanon
| | - Michel Eichelbaum
- Dr. Margarete Fischer-Bosch-Institute of Clinical PharmacologyStuttgart, Germany
- Department of Clinical Pharmacology, University of TübingenTübingen, Germany
- Discipline of Pharmacology, Adelaide Medical School, Faculty of Health and Medical Sciences, The University of Adelaide, AdelaideSA, Australia
| | - Matthias Schwab
- Dr. Margarete Fischer-Bosch-Institute of Clinical PharmacologyStuttgart, Germany
- Department of Clinical Pharmacology, Institute of Experimental and Clinical Pharmacology and Toxicology, University Hospital TübingenTübingen, Germany
- Department of Pharmacy and Biochemistry, University of TübingenTübingen, Germany
- German Cancer Consortium of German Cancer Research CenterHeidelberg, Germany
| | - Hiltrud Brauch
- Dr. Margarete Fischer-Bosch-Institute of Clinical PharmacologyStuttgart, Germany
- Department of Clinical Pharmacology, University of TübingenTübingen, Germany
- German Cancer Consortium of German Cancer Research CenterHeidelberg, Germany
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Peterson A, Xia Z, Chen G, Lazarus P. In vitro metabolism of exemestane by hepatic cytochrome P450s: impact of nonsynonymous polymorphisms on formation of the active metabolite 17 β-dihydroexemestane. Pharmacol Res Perspect 2017; 5:e00314. [PMID: 28603633 PMCID: PMC5464343 DOI: 10.1002/prp2.314] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 03/24/2017] [Indexed: 11/29/2022] Open
Abstract
Exemestane (EXE) is an endocrine therapy commonly used by postmenopausal women with hormone‐responsive breast cancer due to its potency in inhibiting aromatase‐catalyzed estrogen synthesis. Preliminary in vitro studies sought to identify phase I EXE metabolites and hepatic cytochrome P450s (CYP450s) that participate in EXE biotransformation. Phase I metabolites were identified by incubating EXE with HEK293‐overexpressed CYP450s. CYP450s 1A2, 2C8, 2C9, 2C19, 2D6, 3A4, and 3A5 produce 17β‐dihydroexemestane (17β‐DHE), an active major metabolite, as well as two inactive metabolites. 17β‐DHE formation in pooled human liver microsomes subjected to isoform‐specific CYP450 inhibition was also monitored using tandem mass spectrometry. 17β‐DHE production in human liver microsomes was unaffected by isoform‐specific inhibition of CYP450s 2A6, 2B6, and 2E1 but decreased 12–39% following inhibition of drug‐metabolizing enzymes from CYP450 subfamilies 1A, 2C, 2D, and 3A. These results suggest that redundancy exists in the EXE metabolic pathway with multiple hepatic CYP450s catalyzing 17β‐DHE formation in vitro. To further expand the knowledge of phase I EXE metabolism, the impact of CYP450 genetic variation on 17β‐DHE formation was assessed via enzyme kinetic parameters. Affinity for EXE substrate and enzyme catalytic velocity were calculated for hepatic wild‐type CYP450s and their common nonsynonymous variants by monitoring the reduction of EXE to 17β‐DHE. Several functional polymorphisms in xenobiotic‐metabolizing CYP450s 1A2, 2C8, 2C9, and 2D6 resulted in deviant enzymatic activity relative to wild‐type enzyme. Thus, it is possible that functional polymorphisms in EXE‐metabolizing CYP450s contribute to inter‐individual variability in patient outcomes by mediating overall exposure to the drug and its active metabolite, 17β‐DHE.
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Affiliation(s)
- Amity Peterson
- Department of Pharmaceutical Sciences Washington State University Spokane Washington
| | - Zuping Xia
- Department of Pharmaceutical Sciences Washington State University Spokane Washington
| | - Gang Chen
- Department of Pharmaceutical Sciences Washington State University Spokane Washington
| | - Philip Lazarus
- Department of Pharmaceutical Sciences Washington State University Spokane Washington
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Fang P, Zheng X, He J, Ge H, Tang P, Cai J, Hu G. Functional characterization of wild-type and 24 CYP2D6 allelic variants on gefitinib metabolism in vitro. DRUG DESIGN DEVELOPMENT AND THERAPY 2017; 11:1283-1290. [PMID: 28461741 PMCID: PMC5407444 DOI: 10.2147/dddt.s133814] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Background Cytochrome P450 2D6 (CYP2D6), a member of the CYP450 enzyme super family, is a polymorphic enzyme that metabolizes ~25% of therapeutic drugs. CYP2D6 exhibits significant genetic polymorphisms which might cause adverse effects and therapeutic failures of some drugs. Objective The purpose of this study was to evaluate the catalytic activities of 22 novel CYP2D6 alleles (CYP2D6*87, *88, *89, *90, *91, *92, *93, *94, *95, *96, *97, *98, R25Q, F164L, E215K, F219S, V327M, D336N, V342M, R344Q, R440C, R497C) on the metabolism of gefitinib in vitro. Methods and results CYP2D6 variants were incubated with 1–100 μM gefitinib for 60 min at 37°C and the reaction was terminated by cooling to −80°C immediately. Gefitinib and its metabolite O-desmethyl gefitinib were analyzed by an ultra-performance liquid chromatography-tandem mass spectrometry system. Compared to CYP2D6.1, most CYP2D6 variants exhibited significantly decreased relative clearance values (from 3.11% to 79.35%), whereas CYP2D6.92 and CYP2D6.96 displayed no detectable enzyme activity. Only CYP2D6.94 exhibited a markedly increased intrinsic clearance value, and eight variants (CYP2D6.88, CYP2D6.89, CYP2D6.91, CYP2D6.97, V342M, R344Q, F219S, and F164L) showed no significant difference. In addition, 23 CYP2D6 allelic isoforms exhibited substrate inhibition trend toward gefitinib. Conclusion As the first study of all the aforementioned alleles for gefitinib metabolism, these comprehensive data may help in the clinical assessment of the metabolism of gefitinib, and may also offer a reference for personalized treatment with gefitinib in clinical settings.
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Affiliation(s)
- Ping Fang
- Department of Pharmacology, School of Pharmacy, Wenzhou Medical University, Wenzhou, Zhejiang
| | - Xiang Zheng
- Department of Pharmacology, School of Pharmacy, Wenzhou Medical University, Wenzhou, Zhejiang
| | - Jiayang He
- Department of Pharmacology, School of Pharmacy, Wenzhou Medical University, Wenzhou, Zhejiang
| | - Honglei Ge
- Department of Pharmacology, School of Pharmacy, Wenzhou Medical University, Wenzhou, Zhejiang
| | - Pengfei Tang
- Department of Pharmacology, School of Pharmacy, Wenzhou Medical University, Wenzhou, Zhejiang
| | - Jianping Cai
- The Ministry of Health (MOH) Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Beijing, People's Republic of China
| | - Guoxin Hu
- Department of Pharmacology, School of Pharmacy, Wenzhou Medical University, Wenzhou, Zhejiang
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Weng Q, Liang B, Zhou Y, Li X, Wang H, Zhan Y, Dai D, Cai J, Hu G. Effect of 24 cytochrome P450 2D6 variants found in the Chinese population on the N-demethylation of amitriptyline in vitro. PHARMACEUTICAL BIOLOGY 2016; 54:2475-2479. [PMID: 27097346 DOI: 10.3109/13880209.2016.1160250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
CONTEXT Amitriptyline (AT), one of the tricyclic antidepressants, is still widely used for the treatment of the depression and control of anxiety states and panic disorders in the developing countries. OBJECTIVE This study evaluates the catalytic activities of CYP2D6*1, CYP2D6*2, CYP2D6*10 and 22 novel alleles in Han Chinese population and their effects on the N-demethylation of AT in vitro. MATERIALS AND METHODS CYP2D6*1 and 24 CYP2D6 allelic variants were highly expressed in insect cells, and all variants were characterized using AT as a substrate. Reactions were performed at 37 °C with 10-1000 μM substrate for 30 min. We established a HPLC method to quantify the levels of nortriptyline (NT). The kinetic parameters Km, Vmax and intrinsic clearance (Vmax/Km) of NT were calculated. RESULTS Among the 24 CYP2D6 variants, all variants exhibited decreased intrinsic clearance values compared with wild-type CYP2D6.1. Kinetic parameters of two CYP2D6 variants (CYP2D6*92, *96) could not be determined because of absent enzyme activities. CONCLUSIONS The comprehensive in vitro assessment of CYP2D6 variants provides significant insight into allele-specific activity towards AT in vivo.
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Affiliation(s)
- Qinghua Weng
- a School of Pharmacy , Wenzhou Medical University , Wenzhou , Zhejiang , P.R. China
| | - Bingqing Liang
- a School of Pharmacy , Wenzhou Medical University , Wenzhou , Zhejiang , P.R. China
| | - Yali Zhou
- a School of Pharmacy , Wenzhou Medical University , Wenzhou , Zhejiang , P.R. China
| | - Xiangyu Li
- a School of Pharmacy , Wenzhou Medical University , Wenzhou , Zhejiang , P.R. China
| | - Hao Wang
- a School of Pharmacy , Wenzhou Medical University , Wenzhou , Zhejiang , P.R. China
| | - Yunyun Zhan
- a School of Pharmacy , Wenzhou Medical University , Wenzhou , Zhejiang , P.R. China
| | - Dapeng Dai
- b The Key Laboratory of Geriatrics , Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health , Beijing , P.R. China
| | - JianPing Cai
- b The Key Laboratory of Geriatrics , Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health , Beijing , P.R. China
| | - Guoxin Hu
- a School of Pharmacy , Wenzhou Medical University , Wenzhou , Zhejiang , P.R. China
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Hu XX, Zhou Q, Lan T, Huang XX, Liang BQ, Dai DP, Cai JP, Hu GX. Functional characterization of 22 novel CYP2D6 variants for the metabolism of Tamoxifen. ACTA ACUST UNITED AC 2016; 68:819-25. [PMID: 27109434 DOI: 10.1111/jphp.12556] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 03/13/2016] [Indexed: 11/29/2022]
Abstract
OBJECTIVES This study aimed to assess the catalytic characteristics of 24 CYP2D6 allelic isoforms found in Chinese Han population on the metabolism of tamoxifen in vitro. METHODS Recombinant CYP2D6 microsomes of distinguished genotypes were used to characterize the corresponding enzyme activity towards tamoxifen. About 5-2500 μm tamoxifen was incubated for 30 min at 37 °C. Using high-performance liquid chromatography to detect the products, the kinetic parameters Km , Vmax and intrinsic clearance (Vmax /Km ) of N-desmethyltamoxifen were determined. KEY FINDINGS Of the 24 tested allelic variants, the differences of intrinsic clearance value were shown as follows: CYP2D6.89 was much higher than wild-type CYP2D6.1, 2 allelic isoforms (CYP2D6.88 and D336N) exhibited similar intrinsic clearance values as the wild-type enzyme, two variants displayed weak or no activity, while the rest 19 variants showed significantly reduced intrinsic clearance values ranging from 7.46 to 81.11%. CONCLUSION The comprehensive assessment of CYP2D6 variants provides significant insights into allele-specific activity towards tamoxifen in vitro, suggesting that most of the carriers of these alleles might be paid more attention when using CYP2D6-mediated drugs clinically.
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Affiliation(s)
- Xiao-Xia Hu
- Department of Pharmacology, School of Pharmacy of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Quan Zhou
- Department of Pharmacology, School of Pharmacy of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Tian Lan
- Department of Pharmacology, School of Pharmacy of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiang-Xin Huang
- Department of Pharmacology, School of Pharmacy of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Bing-Qing Liang
- Department of Pharmacology, School of Pharmacy of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Da-Peng Dai
- The Key Laboratory of Geriatrics, Beijing Hospital & Beijing Institute of Geriatrics Ministry of Health, Beijing, China
| | - Jian-Ping Cai
- The Key Laboratory of Geriatrics, Beijing Hospital & Beijing Institute of Geriatrics Ministry of Health, Beijing, China
| | - Guo-Xin Hu
- Department of Pharmacology, School of Pharmacy of Wenzhou Medical University, Wenzhou, Zhejiang, China
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Xu RA, Gu EM, Zhou Q, Yuan L, Hu X, Cai J, Hu G. Effects of 22 novel CYP2D6 variants found in Chinese population on the metabolism of dapoxetine. DRUG DESIGN DEVELOPMENT AND THERAPY 2016; 10:687-96. [PMID: 26937172 PMCID: PMC4762583 DOI: 10.2147/dddt.s97789] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Background CYP2D6 is one of the most important members of the cytochrome P450 superfamily. Its genetic polymorphism significantly influences the efficacy and safety of some drugs, which might cause adverse effects and therapeutic failure. Methods and results The aim of this research was mainly to explore the catalytic activities of 22 newly reported CYP2D6 isoforms (2D6*87, *88, *89, *90, *91, *92, *93, *94, *95, *96,*97, *98, *R25Q, F164L, E215K, F219S, V327M, D336N, V342M, R344Q, R440C, R497C) on dapoxetine in vitro. The research was designed with an appropriate incubation system in test tubes and carried out in the constant temperature water. Through detecting its two metabolites desmethyldapoxetine and dapoxetine-N-oxide, the available data were obtained to explain the influence of CYP2D6 polymorphism on the substrate drug dapoxetine. As a result, the intrinsic clearance (Vmax/Km) values of most variants were significantly altered when compared with the counterpart of CYP2D6*1, with most of these variants exhibiting either reduced Vmax and/or increased Km values. For dapoxetine demethylation pathway (which produces desmethyldapoxetine), 2D6*89 and E215K exhibited no markedly decreased relative clearance of 92.81% and 97.70%, respectively. The relative clearance of rest 20 variants exhibited decrease in different levels, ranging from 20.44% to 90.90%. For the dapoxetine oxidation pathway (which produces dapoxetine-N-oxide), the relative clearance values of three variants, 2D6*90, *94, and V342M, exhibited no markedly increased relative clearance of 106.17%, 107.78%, and 109.98%, respectively; the rest 19 variants exhibited significantly decreased levels ranging from 27.56% to 84.64%. In addition, the kinetic parameters of two CYP2D6 variants (2D6*92 and 2D6*96) could not be detected, due to the defect of the CYP2D6 gene. Conclusion As the first report of all aforementioned alleles for dapoxetine metabolism, these data may help in the clinical assessment of the metabolic elimination of dapoxetine and may provide fundamental information for further clinical studies.
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Affiliation(s)
- Ren-ai Xu
- Department of Pharmacy, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China
| | - Er-min Gu
- Department of Pharmacology, School of Pharmacy, Wenzhou Medical University, Wenzhou, People's Republic of China
| | - Quan Zhou
- Department of Pharmacology, School of Pharmacy, Wenzhou Medical University, Wenzhou, People's Republic of China
| | - Lingjing Yuan
- Department of Pharmacology, School of Pharmacy, Wenzhou Medical University, Wenzhou, People's Republic of China
| | - Xiaoxia Hu
- Department of Pharmacology, School of Pharmacy, Wenzhou Medical University, Wenzhou, People's Republic of China
| | - Jianping Cai
- The Key Laboratory of Geriatrics, Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing, People's Republic of China
| | - Guoxin Hu
- Department of Pharmacy, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China; Department of Pharmacology, School of Pharmacy, Wenzhou Medical University, Wenzhou, People's Republic of China
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Hu XX, Yuan LJ, Fang P, Mao YH, Zhan YY, Li XY, Dai DP, Cai JP, Hu GX. Effect of CYP2D6 genetic polymorphism on the metabolism of citalopram in vitro. Drug Metab Pharmacokinet 2016; 31:133-8. [PMID: 27016952 DOI: 10.1016/j.dmpk.2016.01.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 12/21/2015] [Accepted: 01/14/2016] [Indexed: 12/17/2022]
Abstract
Genetic polymorphisms of CYP2D6 significantly influence the efficacy and safety of some drugs, which might cause adverse effects and therapeutic failure. We aimed at investigating the role of CYP2D6 in the metabolism of citalopram and identifying the effect of 24 CYP2D6 allelic variants we found in Chinese Han population on the metabolism of citalopram in vitro. These CYP2D6 variants expressed by insect cells system were incubated with 10-1000 μM citalopram for 30 min at 37 °C and the reaction was terminated by cooling to -80 °C immediately. Citalopram and its metabolites were analyzed by high-performance liquid chromatography (HPLC). The intrinsic clearance (Vmax/Km) values of the variants toward citalopram metabolites were significantly altered, 38-129% for demethylcitalopram and 13-138% for citalopram N-oxide when compared with CYP2D6*1. Most of the tested rare alleles exhibited significantly decreased values due to increased Km and/or decreased Vmax values. We conclude that recombinant system could be used to investigate the enzymes involved in drug metabolism and these findings suggest that more attention should be paid to subjects carrying these CYP2D6 alleles when administering citalopram in the clinic.
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Affiliation(s)
- Xiao-Xia Hu
- Department of Pharmacology, School of Pharmacy of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Ling-Jing Yuan
- Department of Pharmacology, School of Pharmacy of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Ping Fang
- Department of Pharmacology, School of Pharmacy of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yong-Hui Mao
- Department of Nephrology, Beijing Hospital, Ministry of Health, Beijing, China
| | - Yun-Yun Zhan
- Department of Pharmacology, School of Pharmacy of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiang-Yu Li
- Department of Pharmacology, School of Pharmacy of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Da-Peng Dai
- The Key Laboratory of Geriatrics, Beijing Hospital, Beijing Institute of Geriatrics, Ministry of Health, Beijing, China
| | - Jian-Ping Cai
- The Key Laboratory of Geriatrics, Beijing Hospital, Beijing Institute of Geriatrics, Ministry of Health, Beijing, China.
| | - Guo-Xin Hu
- Department of Pharmacology, School of Pharmacy of Wenzhou Medical University, Wenzhou, Zhejiang, China.
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Liang B, Zhan Y, Wang Y, Gu E, Dai D, Cai J, Hu G. Effect of 24 Cytochrome P450 2D6 Variants Found in the Chinese Population on Atomoxetine Metabolism in vitro. Pharmacology 2015; 97:78-83. [PMID: 26666748 DOI: 10.1159/000442952] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 11/29/2015] [Indexed: 11/19/2022]
Abstract
OBJECTIVE The aim of this article was to assess the catalytic activities of 24 cytochrome P450 2D6 (CYP2D6) variants found in the Chinese population toward atomoxetine in vitro as well as CYP2D6.1. METHODS In this study, the co-expression enzyme of human recombinant CYPOR, CYPb5, and CYP2D6.1 or other CYP2D6 variants with the baculovirus-mediated insect cells (Sf21) was used to study the catalytic activities of 24 CYP2D6 variants toward atomoxetine metabolism. The metabolite of atomoxetine (4-hydroxyatomoxetine) was detected by ultra-high performance liquid chromatography-mass spectrometry method. RESULTS The intrinsic clearance (Vmax/Km) values of most variants were significantly altered when compared with CYP2D6.1. CYP2D6.94, CYP2D6.D336N, CYP2D6.R440C exhibited marked increased values 172, 126, 121% respectively. CYP2D6.89 and CYP2D6.98 exhibited similar catalytic activity as the wild type, whereas 17 variants exhibited significantly decreased values (from 5 to 87%) due to increase Km and/or decrease Vmax values. However, CYP2D6.92 and CYP2D6.96 showed no or few activity because of producing nothing. CONCLUSIONS Our results suggest that most of these newly found variants exhibit significantly changed catalytic activities compared with the wild type. And these findings provide valuable information for the growth and development of personalized medicine in China.
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Affiliation(s)
- Bingqing Liang
- School of Pharmacy, Wenzhou Medical University, Wenzhou, China
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Xu Q, Wu Z, Yang L, Zhang X, Gai Z, Chen L, He L, Qin S. Functional characterization of CYP2D6 novel allelic variants identified in the Chinese Han population. Pharmacogenomics 2015; 17:119-9. [PMID: 26652007 DOI: 10.2217/pgs.15.148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
AIM This study was aimed to functionally characterize four novel CYP2D6 alleles identified in Chinese Han population. MATERIALS & METHODS CYP2D6 proteins of wild-type and the four novel variants along with CYP2D6.2 and CYP2D6.10 were heterologously expressed in yeast cells and the kinetic parameters were determined. RESULTS Compared with CYP2D6.1 (frequency in Chinese 24.65%), CYP2D6.X (1.63%), CYP2D6.Y (1.50%), CYP2D6.Z (0.81%), CYP2D6.10 (52.53%) and CYP2D6.75 (0.13%) exhibited low activity at different degrees, whereas the kinetic parameters of CYP2D6.2 (11.06%) were much the same with CYP2D6.1. The novel allele CYP2D6.75 showed decreased enzyme activity. CONCLUSION This is the first study to conduct functional analysis of CYP2D6 four novel alleles in Chinese Han population, which might be helpful for optimizing pharmacotherapy and the design of personalized medicine.
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Affiliation(s)
- Qingqing Xu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental & Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
| | - Zhenqiang Wu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental & Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
| | - Lun Yang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental & Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
| | | | - Zhongtao Gai
- Jinan Infectious Disease Hospital, Shandong University, Jinan, China
| | - Lili Chen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental & Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
| | - Lin He
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental & Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China
| | - Shengying Qin
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental & Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China
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Pharmacogenetic comparison of CYP2D6 predictive and measured phenotypes in a South African cohort. THE PHARMACOGENOMICS JOURNAL 2015; 16:566-572. [PMID: 26503815 DOI: 10.1038/tpj.2015.76] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 08/20/2015] [Accepted: 09/08/2015] [Indexed: 11/08/2022]
Abstract
The relationship between genetic variation in CYP2D6 and variable drug response represents a potentially powerful pharmacogenetic tool. However, little is known regarding this relationship in the genetically diverse South African population. The aim was therefore to evaluate the relationship between predicted and measured CYP2D6 phenotype. An XL-PCR+Sequencing approach was used to determine CYP2D6 genotype in 100 healthy volunteers and phenotype was predicted using activity scores. With dextromethorphan as the probe drug, metabolic ratios served as a surrogate measure of in vivo CYP2D6 activity. Three-hour plasma metabolic ratios of dextrorphan/dextromethorphan were measured simultaneously using semi-automated online solid phase extraction coupled with tandem mass spectrometry. Partial adaptation of the activity score system demonstrated a strong association between genotype and phenotype, as illustrated by a kappa value of 0.792, inter-rater discrepancy of 0.051 and sensitivity of 72.7%. Predicted phenotype frequencies using the modified activity score were 1.3% for poor metabolisers (PM), 7.6% for intermediate metabolisers (IM) and 87.3% for extensive metabolisers (EM). Measured phenotype frequencies were 1.3% for PM, 13.9% for IM and 84.8% for EM. Comprehensive CYP2D6 genotyping reliably predicts CYP2D6 activity in this South African cohort and can be utilised as a valuable pharmacogenetic tool.
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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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Zhan YY, Liang BQ, Wang H, Wang ZH, Weng QH, Dai DP, Cai JP, Hu GX. Effect of CYP2D6 variants on venlafaxine metabolism in vitro. Xenobiotica 2015; 46:424-9. [DOI: 10.3109/00498254.2015.1089364] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Han C, Wang SM, Lee SJ, Jun TY, Pae CU. Optimizing the Use of Aripiprazole Augmentation in the Treatment of Major Depressive Disorder: From Clinical Trials to Clinical Practice. Chonnam Med J 2015; 51:66-80. [PMID: 26306301 PMCID: PMC4543152 DOI: 10.4068/cmj.2015.51.2.66] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 07/20/2015] [Accepted: 07/21/2015] [Indexed: 12/12/2022] Open
Abstract
Major depressive disorder (MDD) is a recurrent, chronic, and devastating disorder leading to serious impairment in functional capacity as well as increasing public health care costs. In the previous decade, switching therapy and dose adjustment of ongoing antidepressants was the most frequently chosen subsequent treatment option for MDD. However, such recommendations were not based on firmly proven efficacy data from well-designed, placebo-controlled, randomized clinical trials (RCTs) but on practical grounds and clinical reasoning. Aripiprazole augmentation has been dramatically increasing in clinical practice owing to its unique action mechanisms as well as proven efficacy and safety from adequately powered and well-controlled RCTs. Despite the increased use of aripiprazole in depression, limited clinical information and knowledge interfere with proper and efficient use of aripiprazole augmentation for MDD. The objective of the present review was to enhance clinicians' current understanding of aripiprazole augmentation and how to optimize the use of this therapy in the treatment of MDD.
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Affiliation(s)
- Changsu Han
- Department of Psychiatry, College of Medicine, Korea University, Seoul, Korea
| | - Sheng-Min Wang
- International Health Care Center, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Soo-Jung Lee
- Department of Psychiatry, Bucheon St. Mary's Hospital, The Catholic University of Korea College of Medicine, Busan, Korea
| | - Tae-Youn Jun
- Department of Psychiatry, St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Chi-Un Pae
- Department of Psychiatry, Bucheon St. Mary's Hospital, The Catholic University of Korea College of Medicine, Busan, Korea. ; Department of Psychiatry and Behavioral Medicines, Duke University Medical Center, Durham, NC, USA
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Luo X, Lei Y, He L, Liu W, Li M, Ran L, Yu M, Guo X, Yu P, Liu Z, Cheng Z. No influence of CYP2D6*10 genotype and phenotype on the pharmacokinetics of nebivolol in healthy Chinese subjects. J Clin Pharm Ther 2015. [PMID: 26214065 DOI: 10.1111/jcpt.12310] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
WHAT IS KNOWN AND OBJECTIVE Nebivolol, a clinically important antihypertensive drug, mainly metabolized by cytochrome P450 (CYP) 2D6, shows wide interindividual variability in pharmacokinetics. The CYP2D6*10 allele (100C>T; rs1065852), present at a high frequency in the Chinese population, is associated with alteration in the pharmacokinetics of many drugs, but its effect on the pharmacokinetics of nebivolol is unknown. The aim of our study was to investigate whether the CYP2D6*10 genotype and phenotype are associated with changes in the pharmacokinetics of nebivolol in Chinese subjects. METHODS Twenty-four healthy subjects were divided into three groups according to CYP2D6*1/*1 (n = 7), CYP2D6*1/*10 (n = 5) and CYP2D6*10/*10 (n = 12) genotypes. The *1/*1 homozygotes and *1/*10 heterozygotes were C allele carriers. All subjects received oral single dose of nebivolol and dextromethorphan. Blood and urine samples were gathered at various times. RESULTS There were no statistically significant differences in the pharmacokinetics of nebivolol between the three CYP2D6*10 genotypes, and no gene-dose effect was seen. The pharmacokinetic parameters of CYP2D6*10/*10 subjects were also similar to those of CYP2D6*1 carriers. A weak relationship between CYP2D6 phenotype and nebivolol clearance was found. WHAT IS NEW AND CONCLUSION The CYP2D6*10 genotype and phenotype were not associated with significant alterations in the pharmacokinetics of nebivolol. CYP2D6*10 alone does not account for the large interindividual differences observed in the disposition of nebivolol among Chinese healthy subjects.
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Affiliation(s)
- X Luo
- School of Life Sciences, Central South University, Changsha, China.,Research Institute of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Central South University, Changsha, China
| | - Y Lei
- Research Institute of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Central South University, Changsha, China.,Haikou People's Hospital and Affiliated Haikou Hospital of Xiangya Medical School, Central South University, Haikou, China
| | - L He
- Research Institute of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Central South University, Changsha, China
| | - W Liu
- Research Institute of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Central South University, Changsha, China
| | - M Li
- Research Institute of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Central South University, Changsha, China
| | - L Ran
- Hunan Tiger Xiangya R&D Co., Ltd, Changsha, China
| | - M Yu
- Hunan Tiger Xiangya R&D Co., Ltd, Changsha, China
| | - X Guo
- Hunan Tiger Xiangya R&D Co., Ltd, Changsha, China
| | - P Yu
- Research Institute of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Central South University, Changsha, China
| | - Z Liu
- Hunan Tiger Xiangya R&D Co., Ltd, Changsha, China
| | - Z Cheng
- Research Institute of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Central South University, Changsha, China
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Varela N, Quiñones LA, Stojanova J, Garay J, Cáceres D, Cespedes S, Sasso J, Miranda C. Characterization of the CYP2D6 drug metabolizing phenotypes of the Chilean mestizo population through polymorphism analyses. Pharmacol Res 2015. [PMID: 26211952 DOI: 10.1016/j.phrs.2015.07.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
We tested the influence of four polymorphisms and gene duplication in CYP2D6 on in vivo enzyme activity in a Chilean mestizo population in order to identify the most relevant genetic profiles that account for observed phenotypes in this ethnic group. CYP2D6*2 (2850C>T), *3 (2549A>del), *4 (1846G>A), *17 (1023C>T) and gene duplication were determined by PCR-RFLP or PCRL in a group of 321 healthy volunteers. Individuals with different variant alleles were phenotyped by determining debrisoquine 4-hydroxylase activity as a metabolic ratio (MR) using a validated HPLC assay. Minor allele frequencies were 0.41, 0.01, 0.12 and 0.00 for CYP2D6*2, *3, *4 and *17 variants, respectively, and the duplication frequency was 0.003. Genotype analysis correlated with phenotypes in 18 of 23 subjects (78.3%). 11 subjects were extensive metabolizers (EM), 8 were intermediate metabolizers (IM), 2 were poor metabolizers (PM) and 2 were ultra-rapid metabolizers (UM) which is fairly coincident with expected phenotypes metabolic ratios ranged from 0.11 to 126.41. The influence of CYP2D6*3 was particularly notable, although only heterozygote carriers were present in our population. Individuals homozygous for *4 were always PM. As expected, the only subject with gene duplication was UM. In conclusion, there was a clear effect of genotype on observed CYP2D6 activity. Classification of EM, PM and UM through genotyping was useful to characterize CYP2D6 phenotype in the Chilean mestizo population.
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Affiliation(s)
- Nelson Varela
- Laboratory of Chemical Carcinogenesis and Pharmacogenetics, ICBM, Program of Molecular and Clinical Pharmacology, Faculty of Medicine, University of Chile, Chile; Department of Medical Technology, Faculty of Medicine, University of Chile, Chile
| | - Luis A Quiñones
- Laboratory of Chemical Carcinogenesis and Pharmacogenetics, ICBM, Program of Molecular and Clinical Pharmacology, Faculty of Medicine, University of Chile, Chile.
| | - Jana Stojanova
- Laboratory of Chemical Carcinogenesis and Pharmacogenetics, ICBM, Program of Molecular and Clinical Pharmacology, Faculty of Medicine, University of Chile, Chile
| | - Joselyn Garay
- Laboratory of Chemical Carcinogenesis and Pharmacogenetics, ICBM, Program of Molecular and Clinical Pharmacology, Faculty of Medicine, University of Chile, Chile
| | - Dante Cáceres
- Laboratory of Chemical Carcinogenesis and Pharmacogenetics, ICBM, Program of Molecular and Clinical Pharmacology, Faculty of Medicine, University of Chile, Chile; Environmental Health Program, School of Public Health, Faculty of Medicine, University of Chile, Chile
| | - Silvia Cespedes
- Laboratory of Chemical Carcinogenesis and Pharmacogenetics, ICBM, Program of Molecular and Clinical Pharmacology, Faculty of Medicine, University of Chile, Chile
| | - Jaime Sasso
- Laboratory of Chemical Carcinogenesis and Pharmacogenetics, ICBM, Program of Molecular and Clinical Pharmacology, Faculty of Medicine, University of Chile, Chile
| | - Carla Miranda
- Laboratory of Chemical Carcinogenesis and Pharmacogenetics, ICBM, Program of Molecular and Clinical Pharmacology, Faculty of Medicine, University of Chile, Chile
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Akiyoshi T, Ishiuchi M, Imaoka A, Ohtani H. Variation in the inhibitory potency of terbinafine among genetic variants of CYP2D6. Drug Metab Pharmacokinet 2015. [PMID: 26195224 DOI: 10.1016/j.dmpk.2015.04.003] [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] [Indexed: 11/17/2022]
Abstract
Cytochrome P450 2D6 (CYP2D6) is a highly polymorphic enzyme that is involved in the metabolism of many drugs. Terbinafine (TER) is a CYP2D6 inhibitor and causes persistent drug interactions in the clinical setting; however, its inhibitory mechanism and the differences in its inhibitory potency among genetic variants of CYP2D6 remain to be investigated. This study aimed to investigate the inhibitory mechanism of TER and the differences in its inhibitory potency among three CYP2D6 variants, CYP2D6.1, CYP2D6.2, and CYP2D6.10. In a competitive inhibition study, the metabolic activity of the CYP2D6 was assessed based on their demethylation of dextromethorphan in the presence or absence of TER, and the time-dependency of the inhibitory effects were examined by preincubating the enzymes with TER. TER had weaker inhibitory effects on CYP2D6.2 and CYP2D6.10 than on CYP2D6.1; i.e., TER exhibited Ki values (the concentration of inhibitor that results in half-maximal inhibition) of 0.0525, 0.355, and 1.85 μM for CYP2D6.1, CYP2D6.2, and CYP2D6.10, respectively. The inhibitory effects of TER were not time-dependent. Since TER's Ki value for CYP2D6.10 was 35.2-fold higher than its Ki value for CYP2D6.1, the CYP2D6 genotype of subjects should be taken into account when estimating the severity of drug interactions involving TER.
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Affiliation(s)
| | | | - Ayuko Imaoka
- Keio University, Faculty of Pharmacy, Tokyo, Japan
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The impact of CYP2D6 polymorphisms on the pharmacokinetics of codeine and its metabolites in Mongolian Chinese subjects. Eur J Clin Pharmacol 2014; 70:57-63. [PMID: 24077935 DOI: 10.1007/s00228-013-1573-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 07/31/2013] [Indexed: 10/26/2022]
Abstract
PURPOSE Codeine is an analgesic drug acting on μ-opioid receptors predominantly via its metabolite morphine formed almost exclusively by CYP2D6. Genetic polymorphisms in CYP2D6 are associated with diminished pain relief and/or severe opioid side effects. In Chinese individuals, CYP2D6*10 is the most common allele with reduced enzyme activity. In this study, we investigated the effect of this allele on the pharmacokinetics of codeine and its metabolites. METHOD A blood sample was collected from healthy Mongolian volunteers for CYP2D6 genotyping using a PCR-RFLP assay. A pharmacokinetic study was then carried out in three groups with CYP2D6*1/*1 (n=10), CYP2D6*1/*10 (n=10) and CYP2D6*10/*10 (n=9) genotypes by collecting serial blood samples for determination of plasma levels of codeine and its metabolites, morphine, morphine 3-glucuronide (M3G) and morphine 6-glucuronide (M6G) before and after a single 30-mg oral dose of codeine phosphate. Codeine and its metabolites were measured by LC-MS/MS. RESULTS No significant differences were observed in the pharmacokinetic parameters of codeine in the three genotype groups. However, the C( max) and AUC(0-∞) of morphine, M3G and M6G were significantly different between the study groups (P<0.05). Compared with the *1/*1 group, the AUC(0-∞) for morphine in the *1/*10 and *10/*10 groups decreased by ratios (95 % CI) of 0.93 (0.26-1.59) and 0.494 (0.135-0.853) respectively. Corresponding ratios for M3G were 0.791 (0.294-1.288) and 0.615 (0.412-0.818) and for M6G were 0.643 (0.39-0.957) and 0.423 (0.267-0.579). CONCLUSION This study demonstrates that the CYP2D6*10 allele plays an important role in the pharmacokinetics of the O-demethylated metabolites of codeine after oral administration.
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71
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Spina E, de Leon J. Clinical applications of CYP genotyping in psychiatry. J Neural Transm (Vienna) 2014; 122:5-28. [DOI: 10.1007/s00702-014-1300-5] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 08/18/2014] [Indexed: 12/13/2022]
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Housman G, Byler S, Heerboth S, Lapinska K, Longacre M, Snyder N, Sarkar S. Drug Resistance in Cancer: An Overview. Cancers (Basel) 2014. [DOI: 78495111110.3390/cancers6031769' target='_blank'>'"<>78495111110.3390/cancers6031769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [78495111110.3390/cancers6031769','', '10.1124/dmd.107.015354')">Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
78495111110.3390/cancers6031769" />
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73
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Housman G, Byler S, Heerboth S, Lapinska K, Longacre M, Snyder N, Sarkar S. Drug resistance in cancer: an overview. Cancers (Basel) 2014; 6:1769-92. [PMID: 25198391 PMCID: PMC4190567 DOI: 10.3390/cancers6031769] [Citation(s) in RCA: 1523] [Impact Index Per Article: 152.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 08/25/2014] [Accepted: 08/29/2014] [Indexed: 02/06/2023] Open
Abstract
Cancers have the ability to develop resistance to traditional therapies, and the increasing prevalence of these drug resistant cancers necessitates further research and treatment development. This paper outlines the current knowledge of mechanisms that promote or enable drug resistance, such as drug inactivation, drug target alteration, drug efflux, DNA damage repair, cell death inhibition, and the epithelial-mesenchymal transition, as well as how inherent tumor cell heterogeneity plays a role in drug resistance. It also describes the epigenetic modifications that can induce drug resistance and considers how such epigenetic factors may contribute to the development of cancer progenitor cells, which are not killed by conventional cancer therapies. Lastly, this review concludes with a discussion on the best treatment options for existing drug resistant cancers, ways to prevent the formation of drug resistant cancers and cancer progenitor cells, and future directions of study.
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Affiliation(s)
- Genevieve Housman
- School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85287, USA.
| | - Shannon Byler
- Cancer Center, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA.
| | - Sarah Heerboth
- Cancer Center, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA.
| | - Karolina Lapinska
- Cancer Center, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA.
| | | | - Nicole Snyder
- Cancer Center, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA.
| | - Sibaji Sarkar
- Cancer Center, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA.
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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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Qu Q, Qu J, Han L, Zhan M, Wu LX, Zhang YW, Zhang W, Zhou HH. Inhibitory effects of phytochemicals on metabolic capabilities of CYP2D6(*)1 and CYP2D6(*)10 using cell-based models in vitro. Acta Pharmacol Sin 2014; 35:685-96. [PMID: 24786236 DOI: 10.1038/aps.2013.202] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 11/11/2013] [Indexed: 11/09/2022] Open
Abstract
AIM Herbal products have been widely used, and the safety of herb-drug interactions has aroused intensive concerns. This study aimed to investigate the effects of phytochemicals on the catalytic activities of human CYP2D6(*)1 and CYP2D6(*)10 in vitro. METHODS HepG2 cells were stably transfected with CYP2D6(*)1 and CYP2D6(*)10 expression vectors. The metabolic kinetics of the enzymes was studied using HPLC and fluorimetry. RESULTS HepG2-CYP2D6(*)1 and HepG2-CYP2D6(*)10 cell lines were successfully constructed. Among the 63 phytochemicals screened, 6 compounds, including coptisine sulfate, bilobalide, schizandrin B, luteolin, schizandrin A and puerarin, at 100 μmol/L inhibited CYP2D6(*)1- and CYP2D6(*)10-mediated O-demethylation of a coumarin compound AMMC by more than 50%. Furthermore, the inhibition by these compounds was dose-dependent. Eadie-Hofstee plots demonstrated that these compounds competitively inhibited CYP2D6(*)1 and CYP2D6(*)10. However, their Ki values for CYP2D6(*)1 and CYP2D6(*)10 were very close, suggesting that genotype-dependent herb-drug inhibition was similar between the two variants. CONCLUSION Six phytochemicals inhibit CYP2D6(*)1 and CYP2D6(*)10-mediated catalytic activities in a dose-dependent manner in vitro. Thus herbal products containing these phytochemicals may inhibit the in vivo metabolism of co-administered drugs whose primary route of elimination is CYP2D6.
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76
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Muroi Y, Saito T, Takahashi M, Sakuyama K, Niinuma Y, Ito M, Tsukada C, Ohta K, Endo Y, Oda A, Hirasawa N, Hiratsuka M. Functional characterization of wild-type and 49 CYP2D6 allelic variants for N-desmethyltamoxifen 4-hydroxylation activity. Drug Metab Pharmacokinet 2014; 29:360-6. [PMID: 24647041 DOI: 10.2133/dmpk.dmpk-14-rg-014] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Genetic variations in cytochrome P450 2D6 (CYP2D6) contribute to interindividual variability in the metabolism of clinically used drugs, e.g., tamoxifen. CYP2D6 is genetically polymorphic and is associated with large interindividual variations in therapeutic efficacy and drug toxicity. In this study, we performed an in vitro analysis of 50 allelic variants of CYP2D6 proteins. Wild-type CYP2D6.1 and 49 variants were transiently expressed in COS-7 cells, and the enzymatic activities of the CYP2D6 variants were characterized using N-desmethyltamoxifen as a substrate. The kinetic parameters K(m), V(max), and intrinsic clearance (V(max)/K(m)) of N-desmethyltamoxifen 4-hydroxylation were determined. Among the 50 CYP2D6 variants, the kinetic parameters for N-desmethyltamoxifen 4-hydroxylation were determined for 20 CYP2D6 variants. On the other hand, the kinetic parameters of 30 CYP2D6 variants could not be determined because the amount of metabolite produced was at or below the detection limit at the lower substrate concentrations. Among them, 8 variants, i.e., CYP2D6.2, .9, .26, .28, .32, .43, .45, and .70, showed decreased intrinsic clearance at <50% of CYP2D6.1. The comprehensive in vitro assessment of CYP2D6 variants provides novel insights into allele-specific activity towards tamoxifen and may be valuable when interpreting in vivo studies.
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Affiliation(s)
- Yuka Muroi
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University
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Wang Z, Wang S, Huang M, Hu H, Yu L, Zeng S. Characterizing the Effect of Cytochrome P450 (CYP) 2C8, CYP2C9, and CYP2D6 Genetic Polymorphisms on Stereoselective N-demethylation of Fluoxetine. Chirality 2014; 26:166-73. [DOI: 10.1002/chir.22289] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 11/24/2013] [Accepted: 11/26/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Zhangting Wang
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences; Zhejiang University; Hangzhou China
| | - Shengjia Wang
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences; Zhejiang University; Hangzhou China
| | - Minmin Huang
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences; Zhejiang University; Hangzhou China
| | - Haihong Hu
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences; Zhejiang University; Hangzhou China
| | - Lushan Yu
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences; Zhejiang University; Hangzhou China
| | - Su Zeng
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences; Zhejiang University; Hangzhou China
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Handa K, Nakagome I, Yamaotsu N, Gouda H, Hirono S. In Silieo Study on the Inhibitory Interaction of Drugs with Wild-type CYP2D6.1 and the Natural Variant CYP2D6.17. Drug Metab Pharmacokinet 2014; 29:52-60. [DOI: 10.2133/dmpk.dmpk-13-rg-044] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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79
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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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80
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Wang YH, Gibson CR. Variability in human in vitro enzyme kinetics. Methods Mol Biol 2014; 1113:337-362. [PMID: 24523120 DOI: 10.1007/978-1-62703-758-7_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
There are many factors which are known to cause variability in human in vitro enzyme kinetic data. Factors such as the source of enzyme and how it was prepared, the genetics and background of the donor, how the in vitro studies are designed, and how the data are analyzed contribute to variability in the resulting kinetic parameters. It is important to consider not only the factors which cause variability within an experiment, such as selection of a probe substrate, but also those that cause variability when comparing kinetic data across studies and laboratories. For example, the artificial nature of the microsomal lipid membrane and microenvironment in some recombinantly expressed enzymes, relative to those found in native tissue microsomes, has been shown to influence enzyme activity and thus can be a source of variability when comparing across the two different systems. All of these factors, and several others, are discussed in detail in the chapter below.
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Affiliation(s)
- Ying-Hong Wang
- Pharmacokinetics, Pharmacodynamics and Drug Metabolism, Merck Research Laboratories, West Point, PA, USA
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81
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Prows CA, Zhang X, Huth MM, Zhang K, Saldaña SN, Daraiseh NM, Esslinger HR, Freeman E, Greinwald JH, Martin LJ, Sadhasivam S. Codeine-related adverse drug reactions in children following tonsillectomy: a prospective study. Laryngoscope 2013; 124:1242-50. [PMID: 24122716 DOI: 10.1002/lary.24455] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 08/13/2013] [Accepted: 09/26/2013] [Indexed: 11/10/2022]
Abstract
OBJECTIVES/HYPOTHESIS To prospectively determine factors associated with codeine's adverse drug reactions (ADRs) at home in a large homogenous population of children undergoing outpatient tonsillectomy. STUDY DESIGN Prospective, genotype blinded, observational study with a single group and repeated ADR measures documented by parents at home. METHODS A total of 249 children 6 to 15 years of age scheduled for tonsillectomy were enrolled. The primary outcome was number of daily codeine-related ADRs. We examined the number and type of ADR by race and by days and further modeled factors potentially associated with ADR risk in a subcohort of white children. Sedation following a dose of codeine was a secondary outcome measure. Parents recorded their children's daily ADRs and sedation scores during postoperative days (POD) 0 to 3 at home. RESULTS Diaries were returned for 134 children, who were given codeine. A total of 106 (79%) reported at least one ADR. The most common ADRs were nausea, lightheadedness/dizziness for white children and nausea, and vomiting for African American children. In a subcohort of white children ≤ 45 kg, increased ADR risk was associated with the presence of one or more full function CYP2D6 alleles (P < 0.001), POD (P < 0.001), and sex (P = 0.027). Increased pain intensity (P = 0.009) and PODs 0 and 1 (P = 0.001) contributed to a higher sedation risk. Neither obstructive apnea nor predicted CYP2D6 phenotype were associated with sedation risk. CONCLUSIONS Our results provide evidence that multiple factors are associated with codeine-related ADRs and support the FDA recommendation to avoid codeine's routine use following tonsillectomy in children.
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Affiliation(s)
- Cynthia A Prows
- Division of Human Genetics, University of Cincinnati, Cincinnati, Ohio; Division of Pharmacy, University of Cincinnati, Cincinnati, Ohio
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82
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Su KP, Wang SM, Pae CU. Omega-3 polyunsaturated fatty acids for major depressive disorder. Expert Opin Investig Drugs 2013; 22:1519-34. [DOI: 10.1517/13543784.2013.836487] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Abstract
Major depressive disorder (MDD) is a chronic, recurrent mental disease that causes serious disability. Because currently available antidepressants have limited efficacy with respect to response and remission in patients with MDD, clinicians must choose the best available treatment interventions for patients who do not respond to initial antidepressant treatment. The existing literature demonstrates that augmentation with atypical antipsychotics (AAs) shows higher response and remission rates compared with antidepressant monotherapy, but is associated with more withdrawals due to adverse events. In this paper, specific clinical issues in the use of AA augmentation for patients with MDD are briefly discussed. Given the limited information and clinical knowledge on the proper and effective use of AAs for MDD, future research should focus on practical clinical issues that can be commonly seen in routine practice but have not been addressed yet. This is because the use of AAs is likely to expand as there is good evidence for their effectiveness and tolerability as augmentation therapy for patients with MDD.
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Affiliation(s)
- Chi-Un Pae
- Department of Psychiatry, Bucheon St Mary's Hospital, The Catholic University of Korea, College of Medicine, 2 Sosa-Dong, Wonmi-Gu, Bucheon, Kyounggi-Do, 420-717, Republic of Korea.
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84
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Do we need to consider ethno-cultural variation in the use of atypical antipsychotics for Asian patients with major depressive disorder? CNS Drugs 2013; 27 Suppl 1:S47-51. [PMID: 23709361 DOI: 10.1007/s40263-012-0033-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Asian and western countries differ in the prevalence, symptom manifestation, diagnostic procedures, patient recognition and treatments of major depressive disorder (MDD), according to a number of studies. Ethnic differences in pharmacological profiles are also important in the prescription of certain antipsychotic medications because they may impact treatment outcomes and adverse events. Differential pharmacokinetic and pharmacodynamic properties of antipsychotics may be practically useful in the control of specific depressive symptoms. Furthermore, patient compliance with prescribed medications has been found to be different across races and ethnicities. Therefore, this article explores practical clinical issues for the use of atypical antipsychotics in patients with MDD, focusing on ethno-cultural differences.
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85
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Matsui A, Azuma J, Witcher JW, Long AJ, Sauer JM, Smith BP, DeSante KA, Read HA, Takahashi M, Nakano M. Pharmacokinetics, Safety, and Tolerability of Atomoxetine and Effect ofCYP2D6*10/*10Genotype in Healthy Japanese Men. J Clin Pharmacol 2013; 52:388-403. [DOI: 10.1177/0091270011398657] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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86
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Castellan AC, Tod M, Gueyffier F, Audars M, Cambriels F, Kassaï B, Nony P. Quantitative Prediction of the Impact of Drug Interactions and Genetic Polymorphisms on Cytochrome P450 2C9 Substrate Exposure. Clin Pharmacokinet 2013; 52:199-209. [DOI: 10.1007/s40262-013-0031-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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87
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Pharmacogenomics. Mol Pharmacol 2012. [DOI: 10.1002/9781118451908.ch7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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88
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Antipsychotics and abnormal liver function tests. Clin Neuropharmacol 2012; 35:297-8. [PMID: 23151471 DOI: 10.1097/wnf.0b013e318278feeb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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89
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Combined Therapy With Thioridazine Decreases Plasma Levels of Quetiapine in Taiwanese Schizophrenic Patients. Ther Drug Monit 2012; 34:345-8. [DOI: 10.1097/ftd.0b013e31825479cc] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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90
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Yang J, He MM, Niu W, Wrighton SA, Li L, Liu Y, Li C. Metabolic capabilities of cytochrome P450 enzymes in Chinese liver microsomes compared with those in Caucasian liver microsomes. Br J Clin Pharmacol 2012; 73:268-84. [PMID: 21815912 DOI: 10.1111/j.1365-2125.2011.04076.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
AIM The most common causes of variability in drug response include differences in drug metabolism, especially when the hepatic cytochrome P450 (CYP) enzymes are involved. The current study was conducted to assess the differences in CYP activities in human liver microsomes (HLM) of Chinese or Caucasian origin. METHODS The metabolic capabilities of CYP enzymes in 30 Chinese liver microsomal samples were compared with those of 30 Caucasian samples utilizing enzyme kinetics. Phenacetin O-deethylation, coumarin 7-hydroxylation, bupropion hydroxylation, amodiaquine N-desethylation, diclofenac 4'-hydroxylation (S)-mephenytoin 4'-hydroxylation, dextromethorphan O-demethylation, chlorzoxazone 6-hydroxylation and midazolam 1'-hydroxylation/testosterone 6β-hydroxylation were used as probes for activities of CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and CYP3A, respectively. Mann-Whitney U test was used to assess the differences. RESULTS The samples of the two ethnic groups were not significantly different in cytochrome-b(5) concentrations but were significantly different in total CYP concentrations and NADPH-P450 reductase activity (P < 0.05). Significant ethnic differences in intrinsic clearance were observed for CYP1A2, CYP2C9, CYP2C19 and CYP2E1; the median values of the Chinese group were 54, 58, 26, and 35% of the corresponding values of the Caucasian group, respectively. These differences were associated with differences in Michaelis constant or maximum velocity. Despite negligible difference in intrinsic clearance, the Michaelis constant of CYP2B6 appeared to have a significant ethnic difference. No ethnic difference was observed for CYP2A6, CYP2C8, CYP2D6 and CYP3A. CONCLUSIONS These data extend our knowledge on the ethnic differences in CYP enzymes and will have implications for drug discovery and drug therapy for patients from different ethnic origins.
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Affiliation(s)
- Junling Yang
- Shanghai Institute of Materia, Chinese Academy of Sciences, Shanghai, China
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91
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Cacabelos R, Martínez R, Fernández-Novoa L, Carril JC, Lombardi V, Carrera I, Corzo L, Tellado I, Leszek J, McKay A, Takeda M. Genomics of Dementia: APOE- and CYP2D6-Related Pharmacogenetics. Int J Alzheimers Dis 2012; 2012:518901. [PMID: 22482072 PMCID: PMC3312254 DOI: 10.1155/2012/518901] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Accepted: 11/12/2011] [Indexed: 01/05/2023] Open
Abstract
Dementia is a major problem of health in developed societies. Alzheimer's disease (AD), vascular dementia, and mixed dementia account for over 90% of the most prevalent forms of dementia. Both genetic and environmental factors are determinant for the phenotypic expression of dementia. AD is a complex disorder in which many different gene clusters may be involved. Most genes screened to date belong to different proteomic and metabolomic pathways potentially affecting AD pathogenesis. The ε4 variant of the APOE gene seems to be a major risk factor for both degenerative and vascular dementia. Metabolic factors, cerebrovascular disorders, and epigenetic phenomena also contribute to neurodegeneration. Five categories of genes are mainly involved in pharmacogenomics: genes associated with disease pathogenesis, genes associated with the mechanism of action of a particular drug, genes associated with phase I and phase II metabolic reactions, genes associated with transporters, and pleiotropic genes and/or genes associated with concomitant pathologies. The APOE and CYP2D6 genes have been extensively studied in AD. The therapeutic response to conventional drugs in patients with AD is genotype specific, with CYP2D6-PMs, CYP2D6-UMs, and APOE-4/4 carriers acting as the worst responders. APOE and CYP2D6 may cooperate, as pleiotropic genes, in the metabolism of drugs and hepatic function. The introduction of pharmacogenetic procedures into AD pharmacological treatment may help to optimize therapeutics.
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Affiliation(s)
- Ramón Cacabelos
- EuroEspes Biomedical Research Center, Institute for CNS Disorders and Genomic Medicine, EuroEspes Chair of Biotechnology and Genomics, Camilo José Cela University, 15165 Bergondo, Spain
| | - Rocío Martínez
- EuroEspes Biomedical Research Center, Institute for CNS Disorders and Genomic Medicine, EuroEspes Chair of Biotechnology and Genomics, Camilo José Cela University, 15165 Bergondo, Spain
| | - Lucía Fernández-Novoa
- EuroEspes Biomedical Research Center, Institute for CNS Disorders and Genomic Medicine, EuroEspes Chair of Biotechnology and Genomics, Camilo José Cela University, 15165 Bergondo, Spain
| | - Juan C. Carril
- EuroEspes Biomedical Research Center, Institute for CNS Disorders and Genomic Medicine, EuroEspes Chair of Biotechnology and Genomics, Camilo José Cela University, 15165 Bergondo, Spain
| | - Valter Lombardi
- EuroEspes Biomedical Research Center, Institute for CNS Disorders and Genomic Medicine, EuroEspes Chair of Biotechnology and Genomics, Camilo José Cela University, 15165 Bergondo, Spain
| | - Iván Carrera
- EuroEspes Biomedical Research Center, Institute for CNS Disorders and Genomic Medicine, EuroEspes Chair of Biotechnology and Genomics, Camilo José Cela University, 15165 Bergondo, Spain
| | - Lola Corzo
- EuroEspes Biomedical Research Center, Institute for CNS Disorders and Genomic Medicine, EuroEspes Chair of Biotechnology and Genomics, Camilo José Cela University, 15165 Bergondo, Spain
| | - Iván Tellado
- EuroEspes Biomedical Research Center, Institute for CNS Disorders and Genomic Medicine, EuroEspes Chair of Biotechnology and Genomics, Camilo José Cela University, 15165 Bergondo, Spain
| | - Jerzy Leszek
- Department of Psychiatry, Medical University of Wroclaw, Pasteura 10, 50-229 Wroclaw, Poland
| | - Adam McKay
- EuroEspes Biomedical Research Center, Institute for CNS Disorders and Genomic Medicine, EuroEspes Chair of Biotechnology and Genomics, Camilo José Cela University, 15165 Bergondo, Spain
| | - Masatoshi Takeda
- Department of Psychiatry and Behavioral Sciences, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-shi, Osaka 565-0871, Japan
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Carvalho M, Carmo H, Costa VM, Capela JP, Pontes H, Remião F, Carvalho F, Bastos MDL. Toxicity of amphetamines: an update. Arch Toxicol 2012; 86:1167-231. [PMID: 22392347 DOI: 10.1007/s00204-012-0815-5] [Citation(s) in RCA: 260] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Accepted: 02/02/2012] [Indexed: 01/06/2023]
Abstract
Amphetamines represent a class of psychotropic compounds, widely abused for their stimulant, euphoric, anorectic, and, in some cases, emphathogenic, entactogenic, and hallucinogenic properties. These compounds derive from the β-phenylethylamine core structure and are kinetically and dynamically characterized by easily crossing the blood-brain barrier, to resist brain biotransformation and to release monoamine neurotransmitters from nerve endings. Although amphetamines are widely acknowledged as synthetic drugs, of which amphetamine, methamphetamine, and 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) are well-known examples, humans have used natural amphetamines for several millenniums, through the consumption of amphetamines produced in plants, namely cathinone (khat), obtained from the plant Catha edulis and ephedrine, obtained from various plants in the genus Ephedra. More recently, a wave of new amphetamines has emerged in the market, mainly constituted of cathinone derivatives, including mephedrone, methylone, methedrone, and buthylone, among others. Although intoxications by amphetamines continue to be common causes of emergency department and hospital admissions, it is frequent to find the sophism that amphetamine derivatives, namely those appearing more recently, are relatively safe. However, human intoxications by these drugs are increasingly being reported, with similar patterns compared to those previously seen with classical amphetamines. That is not surprising, considering the similar structures and mechanisms of action among the different amphetamines, conferring similar toxicokinetic and toxicological profiles to these compounds. The aim of the present review is to give an insight into the pharmacokinetics, general mechanisms of biological and toxicological actions, and the main target organs for the toxicity of amphetamines. Although there is still scarce knowledge from novel amphetamines to draw mechanistic insights, the long-studied classical amphetamines-amphetamine itself, as well as methamphetamine and MDMA, provide plenty of data that may be useful to predict toxicological outcome to improvident abusers and are for that reason the main focus of this review.
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Affiliation(s)
- Márcia Carvalho
- REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Portugal
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Chen SJ, Hsiao YL, Shen TW, Chen ST. The effectiveness and safety of adjunctive aripiprazole in Taiwanese patients with antidepressant-refractory major depressive disorder: a prospective, open-label trial. J Clin Psychopharmacol 2012; 32:56-60. [PMID: 22198444 DOI: 10.1097/jcp.0b013e31823f6c7f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
There is currently no published clinical trial on the safety and effectiveness of aripiprazole in Taiwanese patients with treatment-refractory major depressive disorder. We were interested in determining the applicability of current recommended doses of aripiprazole as an adjunct to antidepressant therapy in this population. We conducted a prospective, open-label nonrandomized, 4-week flexibly dosed (2.5-5 mg/d) trial with aripiprazole augmentation in 9 Taiwanese patients who had a history of nonresponse to at least 2 adequate courses of antidepressant therapy with different types of antidepressants. The primary end point for clinical effectiveness was mean change in the 17-item Hamilton Rating Scale for Depression at the end of the 4-week trial. Secondary end points for clinical effectiveness included mean change in Beck Depression Inventory and Beck Anxiety Inventory scores. The Systematic Assessment of Treatment Emergent Events-General Inquiry was used to assess adverse effects. All patients completed the trial and responded to treatment; the remission rate was 77.8%. The mean daily dose of adjunctive aripiprazole was 4.2 mg. Common treatment-emergent adverse events included insomnia and sedation (33.3%) and akathisia (22.2%). We found high effectiveness despite a lower mean daily dose of adjunctive aripiprazole (4.2 mg) when compared with previously reported findings; however, we also observed a higher frequency of treatment-emergent adverse effects. Additional studies are required to ascertain whether there are ethnic differences in the pharmacokinetics and/or pharmacodynamics of aripiprazole in treatment-refractory depression.
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Affiliation(s)
- Shaw-Ji Chen
- Yuli Mental Research Center, Department of Psychiatry, Yuli Veteran Hospital, Taiwan
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CYP2D6 polymorphisms and codeine analgesia in postpartum pain management: a pilot study. Ther Drug Monit 2012; 33:425-32. [PMID: 21743374 DOI: 10.1097/ftd.0b013e3182272b10] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Codeine, a common opiate prescribed for pain postcesarean section (c-section), is biotransformed by the highly polymorphic Cytochrome P450 enzyme 2D6 (CYP2D6). Ultrarapid metabolizers (UMs), individuals with multiple active copies of CYP2D6, can biotranform up to 50% more codeine into morphine than normal individuals can. In contrast, poor metabolizers (PMs), individuals who have no active CYP2D6 genes, convert almost no codeine into morphine and as a result may take multiple doses of codeine without attaining analgesia. OBJECTIVE The aim was to study the relationship between CYP2D6 genotype and codeine analgesia among women recovering from c-section. METHODS Forty-five mothers prescribed codeine provided a blood sample for CYP2D6 genotyping and recorded their pain level 4 times a day for 3 days immediately after a c-section. Codeine was used on an as-needed basis; doses and times were recorded. The relationship between CYP2D6 genotype, pain scores, need for codeine, and adverse events was studied. Theoretical morphine dose, based on CYP2D6 genotype, was estimated. RESULTS Women at the genotypic extremes reported codeine effects consistent with their genotype: the 2 PMs of codeine reported no analgesia as a result of taking codeine, whereas 2 of the 3 UMs reported immediate pain relief from codeine but stopped taking it due to dizziness and constipation. Much larger numbers are needed to study similar correlations among extensive and intermediate metabolizers. CONCLUSIONS In this pilot study, the extreme CYP2D6 genotypes (PMs and UMs) seemed to predict pain response and adverse events. Larger sample sizes are needed to correlate the range of genotypes with pain response.
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Chiba K, Kato M, Ito T, Suwa T, Sugiyama Y. Inter-individual Variability of In Vivo CYP2D6 Activity in Different Genotypes. Drug Metab Pharmacokinet 2012; 27:405-13. [DOI: 10.2133/dmpk.dmpk-11-rg-078] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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96
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Abstract
The cytochrome P450 (CYP) superfamily is one of the most important groups of enzymes involved in drug metabolism. It is responsible for the metabolism of a large number of drugs. Many CYP isoforms are expressed polymorphically, and catalytic alterations of allelic variant proteins can affect the metabolic activities of many drugs. The CYP2D6, CYP2C9, CYP2C19, and CYP2B6 genes are particularly polymorphic, whereas CYP1A1, CYP1A2, CYP2E1, and CYP3A4 are relatively well conserved without common functional polymorphisms. In vitro studies using cDNA expression systems are useful tools for evaluating functional alterations of the allelic variants of CYP, particularly for low-frequency alleles. Recombinant CYPs have been successfully expressed in bacteria, yeast, baculoviruses, and several mammalian cells. Determination of CYP variant-mediated kinetic parameters (Km and Vmax) in vitro can be useful for predicting drug dosing and clearance in humans. This review focuses on the advantages and disadvantages of the various cDNA-expression systems used to determine the kinetic parameters for CYP allelic variants, the methods for determining the kinetic parameters, and the findings of in vitro studies on highly polymorphic CYPs, including CYP2D6, CYP2C9, CYP2C19, and CYP2B6.
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Affiliation(s)
- Masahiro Hiratsuka
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan.
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97
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Yin SJ, Ni YB, Wang SM, Wang X, Lou YQ, Zhang GL. Differences in genotype and allele frequency distributions of polymorphic drug metabolizing enzymes CYP2C19 and CYP2D6 in mainland Chinese Mongolian, Hui and Han populations. J Clin Pharm Ther 2011; 37:364-9. [DOI: 10.1111/j.1365-2710.2011.01298.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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98
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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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99
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Yamaori S, Okamoto Y, Yamamoto I, Watanabe K. Cannabidiol, a Major Phytocannabinoid, As a Potent Atypical Inhibitor for CYP2D6. Drug Metab Dispos 2011; 39:2049-56. [DOI: 10.1124/dmd.111.041384] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Rossato G, Ernst B, Smiesko M, Spreafico M, Vedani A. Probing small-molecule binding to cytochrome P450 2D6 and 2C9: An in silico protocol for generating toxicity alerts. ChemMedChem 2011; 5:2088-101. [PMID: 21038340 DOI: 10.1002/cmdc.201000358] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Drug metabolism, toxicity, and their interaction profiles are major issues in the drug-discovery and lead-optimization processes. The cytochromes P450 (CYPs) 2D6 and 2C9 are enzymes involved in the oxidative metabolism of a majority of marketed drugs. Therefore, the prediction of the binding affinity towards CYP2D6 and CYP2C9 would be beneficial for identifying cytochrome-mediated adverse effects triggered by drugs or chemicals (e.g., toxic reactions, drug-drug, and food-drug interactions). By identifying the binding mode by using pharmacophore prealignment, automated flexible docking, and by quantifying the binding affinity by multidimensional QSAR (mQSAR), we validated a model family of 56 compounds (46 training, 10 test) and 85 compounds (68 training, 17 test) for CYP2D6 and CYP2C9, respectively. The correlation with the experimental data (cross-validated r²=0.811 for CYP2D6 and 0.687 for CYP2C9) suggests that our approach is suited for predicting the binding affinity of compounds towards CYP2D6 and CYP2C9. The models were challenged by Y-scrambling and by testing an external dataset of binding compounds (15 compounds for CYP2D6 and 40 for CYP2C9). To assess the probability of false-positive predictions, datasets of nonbinders (64 compounds for CYP2D6 and 56 for CYP2C9) were tested by using the same protocol. The two validated mQSAR models were subsequently added to the VirtualToxLab (VTL, http://www.virtualtoxlab.org).
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Affiliation(s)
- Gianluca Rossato
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Switzerland
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