CYP2 D6的基因多态性与药物临床应用

CYP2D6是CYP酶系中重要的一种氧化代谢酶,参与多种药物的代谢。 CYP2D6具有基因多态性,这是构成药物代谢个体差异和种族差异的基础,它主要参与心血管类、抗精神病类、镇痛药、以及一些抗癌药物等的代谢。研究 CYP2D6基因多态性与药物代谢个体差异的相关性,有助于减轻药物不良反应,提高治疗效果,实施个体化给药。     

CYP2D6基因与药物代谢

细胞色素P 45 0 (CYP)中的CYP2D6酶在抗抑郁药、安定药及某些抗心律失常药的代谢中起重要作用 ,CYP2D6基因位于 2 2号常染色体上为隐性遗传 ,CYP2D6基因呈多态性约有 70余种等位基因变异型 ,也存在特异人群差别 ,因而导致所编码的酶活性不同 ,这些数据有助于理解药物代谢的个体差异、有助于预测药物之间的相互作用。     

细胞色素P4502D6基因多态性和药物相互作用

细胞色素P4502D6（CYP2D6）是一种重要的P450系氧化代谢酶,参与多种重要药物的代谢.CYP2D6具有基因多态性,对药物的代谢呈现明显的个体差异.而且CYP2D6能被多种药物竞争性抑制和诱导,药物联用时易产生相互作用.本文从CYP2D6的基因多态性与代谢表型、底物竞争作用、代谢酶的诱导和抑制等方面,探讨CYP2D6基因多态性与药物相互作用的关系.     

限制性片段长度多态性聚合酶链反应法检测人细胞色素氧化酶2D6药物代谢相关基因位点多态性

目的建立测定人细胞色素氧化酶 2D6(CYP2D6)基因多态性的限制性片段长度多态性聚合酶链反应(polymerase chain reaction?restriction fragment length polymorphism,PCR?RFLP)检测方法。方法通过增加 PCR扩增体系中 DNA模板上样体积、降低引物浓度以及减少限制性内切酶的用量等方法改进、优化实验条件,建立以 PCR?RFLP法为基础的肝药酶 CYP2D6基因型检测方法。结果采用 PCR?RFLP法能够检测 CYP2D6?2、CYP2D6?10和 CYP2D6?14基因型,且过程简便,经济实用。结论该方法检测 CYP2D6药物代谢相关基因位点基因型具有简便、高效、准确和经济的特点,可在临床及实验室推广使用。     

氟西汀与抗精神病药相互作用

氟西汀是抗抑郁药的一线药,可与典型抗精神病药物、非典型抗精神病药物发生药物相互作用.氟西汀通过抑制细胞色素P450酶CYP2D6、CYP2C9、CYP3A4、CYP2C19、CYP1A2等,使其血药浓度升高,增加抗精神病药物的不良反应.临床应重视氟西汀与抗精神病药物的相互作用.     

CYP2D6基因多态性对阿立哌唑治疗儿童抽动障碍的血药浓度和临床疗效的影响

目的 考察CYP2D6基因多态性对阿立哌唑治疗儿童抽动障碍的体内药物浓度和临床疗效的影响。方法 选取2021年1月—2022年5月就诊于华中科技大学同济医学院附属武汉儿童医院儿童保健科的抽动障碍患儿作为研究对象,患儿上午口服阿立哌唑片,分别于治疗前和治疗第4、8周后观察并记录患儿的临床疗效和出现的不良反应。治疗达稳态后采集血液样本,检测阿立哌唑、脱氢阿立哌唑血药浓度和CYP2D6基因多态性。结果 超快代谢型、快速代谢型和中速代谢型3组之间阿立哌唑的C/D值、YGTSS减分率、有效率存在统计学差异(P<0.05),不良反应发生率无统计学差异。结论 CYP2D6基因多态性能够显著影响阿立哌唑治疗儿童抽动障碍的血药浓度和临床疗效,为实现个体化给药提供参考。     

CYP2D6*10和CYP2C19*2基因型多态性与接受他莫昔芬治疗乳腺癌患者生存率的相关性研究

目的:研究CYP2D6*10和CYP2C19*2基因型多态性与接受他莫昔芬(tamoxifen,TAM)治疗乳腺癌患者生存率的相关性研究.方法:选择2009至2004年本院甲乳外科和肿瘤内科收治的171名术后服用TAM治疗的雌激素阳性乳腺癌患者,调查TAM使用情况和生存状态等相关资料;收集相关的石蜡组织切片用于DNA提取;用PCR技术检测CYP2D6*10和CYP2C19*2基因型多态性;查明CYP2D6*10和CYP2C19*2基因型多态性与患者生存率的相关性.结果:本次研究中,CYP2D6Wt/Wt、CYP2D6Wt/*10 和CYP2D6*10/*10基因型的总生存率(overall survival,OS)类似,差异无统计学意义(P＞0.05).CYP2C19*2/*2基因型的5年OS明显优于CYP2C19 Wt/Wt,差异具有统计学意义(P＜0.05);CYP2C19*2/*2基因型的10年OS明显优于CYP2C19 Wt/Wt和CYP2C19 Wt/*2,差异具有统计学意义(P＜0.05);但是CYP2C19Wt/Wt与CYP2C19 Wt/*2的5、10年OS差异无统计学意义(P＞0.05).结论:研究结果显示,CYP2D6*10基因型多态性与服用TAM治疗乳腺癌患者的生存率之间不存在相关性;CYP2C19*2基因型多态性与接受TAM治疗乳腺癌患者的生存率之间存在相关性,CYP2C19*2/*2接受TAM治疗乳腺癌患者的生存率最高,CYP2C19 Wt/*2生存率较高,CYP2C19 Wt/Wt较低.     

CYP2D6基因多态性与阿立哌唑及其代谢物血药浓度的相关性研究

目的 研究CYP2D6基因多态性与精神分裂症患者阿立哌唑及其活性代谢物脱氢阿立哌唑血药浓度的相关性。方法 纳入200例经阿立哌唑治疗的精神分裂症患者，采集清晨服药前空腹血，采用LC-MS/MS法测定阿立哌唑及其代谢物脱氢阿立哌唑稳态谷浓度。通过Axiom基因芯片分析技术检测CYP2D6(*2、*5、*10、*41)4个SNP位点的基因型，比较不同基因型患者阿立哌唑及其代谢物的浓度剂量比（C/D）及代谢物与阿立哌唑血药浓度比值（CDARI/CARI）的差异。结果 200例精神分裂症患者CYP2D6正常代谢型与中代谢型患者脱氢阿立哌唑C/D值差异存在统计学意义（P <0.05）;CYP2D6正常代谢型与慢代谢型患者脱氢阿立哌唑C/D值差异存在高度统计学意义（P <0.01）;CYP2D6正常代谢型与慢代谢型患者阿立哌唑及其代谢物总浓度C/D值差异存在统计学意义（P <0.05）。结论 CYP2D6基因多态性可影响阿立哌唑体内药动学过程，建议临床根据患者CYP2D6基因型制定个体化治疗方案。     

细胞色素P4502D6酶基因多态性与利培酮代谢的相关性研究

目的 研究利培酮(抗精神分裂症药)在人体代谢过程与CYP2D6*10基因多态性的关系.方法 不同CYP2D6*1/*1(n=5)、*1/*10(n=12)及*10/*10(n=6)基因型的健康志愿者,单次口服利培酮2 mg后,用LC-MS/MS方法测定血浆中利培酮及其活性代谢产物9-羟基利培酮浓度,研究利培酮药代动力学与CYP2D6*10基因型的相关性.结果 CYP2D6*10/*10和CYP2D6*1/*10基因型与CYP2D6*1/*1基因型的受试者相比,利培酮的AUC0-∞分别增加811%和212%,2者比较差异非常显著(P<0.001);利培酮/9-羟基利培酮的AUC比值在各CYP2D6*10基因型间存在显著性差异(P<0.001).结论 CYP2D6*10 C188T突变使CYP2D6对利培酮的代谢活性降低,体内利培酮暴露量增加.     

基于药物基因组学的选择性5-羟色胺再摄取抑制剂个体化治疗抑郁症

选择性5-羟色胺再摄取抑制剂(SSRIs)是当前治疗抑郁症的一线药物,CYP2D6、CYP2C19基因多态性会影响SSRIs的代谢,进而影响其疗效与安全性.目前我国临床医师对抑郁症患者基于基因多态性的SSRIs个体化治疗实践相对较少.该文就CYP2D6、CYP2C19基因型及其对SSRIs治疗的影响进行综述,以期为抑郁...     

Role of CYP pharmacogenetics and drug-drug interactions in the efficacy and safety of atypical and other antipsychotic agents

Cytochrome P450 (CYP) drug oxidases play a pivotal role in the elimination of antipsychotic agents, and therefore influence the toxicity and efficacy of these drugs. Factors that affect CYP function and expression have a major impact on treatment outcomes with antipsychotic agents. In particular, aspects of CYP pharmacogenetics, and the processes of CYP induction and inhibition all influence in-vivo rates of drug elimination. Certain CYPs that mediate the oxidation of antipsychotic drugs exhibit genetic variants that may influence in-vivo activity. Thus, single nucleotide polymorphisms (SNPs) in CYP genes have been shown to encode enzymes that have decreased drug oxidation capacity. Additionally, psychopharmacotherapy has the potential for drug-drug inhibitory interactions involving CYPs, as well as drug-mediated CYP induction. Literature evidence supports a role for CYP1A2 in the clearance of the atypical antipsychotics clozapine and olanzapine; CYP1A2 is inducible by certain drugs and environmental chemicals. Recent studies have suggested that specific CYP1A2 variants possessing individual SNPs, and possibly also SNP combinations (haplotypes), in the 5'-regulatory regions may respond differently to inducing chemicals. CYP2D6 is an important catalyst of the oxidation of chlorpromazine, thioridazine, risperidone and haloperidol. Certain CYP2D6 allelic variants that encode enzymes with decreased drug oxidation capacity are more common in particular ethnic groups, which may lead to adverse effects with standard doses of psychoactive drugs. Thus, genotyping may be useful for dose optimization with certain psychoactive drugs that are substrates for CYP2D6. However, genotyping for inducible CYPs is unlikely to be sufficient to direct therapy with all antipsychotic agents. In-vivo CYP phenotyping with cocktails of drug substrates may assist at the commencement of therapy, but this approach could be complicated by pharmacokinetic interactions if applied when an antipsychotic drug regimen is ongoing.     

Effect of factors on plasma haloperidol concentration/dose ratio]

It has been known that the serum concentration of antipsychotics is varied according to individual case. There are several factors that may affect the plasma levels of antipsychotics; e.g., antipsychotic dose, body weight, interaction with other drugs, enzyme activity in the human liver, age and smoking. The enzyme cytochrome P450 2D6 (CYP2D6) is an important factor affecting the plasma levels of antipsychotics, because CYP2D6 is involved in the metabolism of these drugs. In this paper, we review the effect of several factors on plasma haloperidol concentration.     

The influence of the CYP2D6 polymorphism on psychopathological and extrapyramidal symptoms in the patients on long-term antipsychotic treatment

Poor response to antipsychotics treatment and extrapyramidal side effects (EPS) are the most challenging problems in the treatment of schizophrenia. Several studies were investigating the impact of polymorphic cytochrome P450 2D6 gene (CYP2D6) on EPS but the results were conflicting. There are practically no clinical studies of long-term treatment of schizophrenia and CYP2D6 polymorphism. Our aim was to evaluate the influence of CYP2D6 genotype on psychopathological symptoms and the occurrence of EPS in Slovenian outpatients with schizophrenia or schizoaffective disorder in stable remission, receiving long-term maintenance antipsychotic treatment. In total 131 outpatients meeting the DSM IV criteria for schizophrenia or schizoaffective disorder and receiving maintenance therapy with haloperidol, fluphenazine, zuclopethixole or risperidone were genotyped for 14 polymorphic CYP2D6 alleles. Psychopathological symptoms were assessed with the Positive and Negative Symptom Scale for Schizophrenia (PANSS). EPS were assessed with the Simpson Angus Scale (SAS), the Barnes Akathisia Scale and the Abnormal Involuntary Movement Scale (AIMS). Six patients (4.6%) were genotyped as poor metabolizers (PMs). PMs scored significantly higher on the negative subscale for PANSS. There were no statistically significant differences between the group of PMs and the group of patients with at least one functional CYP2D6 allele in view of patient's characteristics or any of the items of the AIMS, the SAS or the Barnes Akathisia Scale. CYP2D6 genotype may not be the major factor that determines the susceptibility to antipsychotic-induced EPS in Slovenian patients in stable remission and on maintenance therapy with antipsychotics that are mainly CYP2D6 substrates. However, CYP2D6 genotype might be a factor contributing to the persistent negative symptoms of schizophrenia.     

Clinical implications of CYP2D6 genetic polymorphism during treatment with antipsychotic drugs

CYP2D6 is described as the most relevant enzyme in the metabolism of many antipsychotic drugs. Its contribution to the interindividual differences in drug response is reviewed here highlighting its role in the kinetics of antipsychotic drugs and the occurrence of drug interactions. The activity of CYP2D6 is inherited as a monogenetic trait and the CYP2D6 gene appears highly polymorphic in humans. The polymorphic alleles may lead to altered activity of the CYP enzymes causing absent, decreased (poor), or increased (ultrarapid) metabolism that in turn influence the disposition of the antipsychotic drugs. Antipsychotic drug biotransformation is mainly determined by genetic factors mediating CYP2D6 gene polymorphism, however the importance of environmental factors (dietary, smoking, diseases, etc.) is also recognized. Additionally, the potential interaction between CYP2D6 and the endogenous metabolism must be taken into consideration. The present review summarizes the relevance of physiological and environmental factors in CYP2D6 hydroxylation capacity, the inhibition of CYP2D6 activity during treatment, the use of drug/metabolite ratio as a tool to evaluate CYP2D6 hydroxylation capacity in a patient, and the relevance of CYP2D6 for drug plasma concentration and for QTc interval lengthening during treatment with antipsychotic drugs.     

The association between CYP2D6 genotype and switching antipsychotic medication to clozapine

Purpose

Genetic variation in the cytochrome P450 2D6 (CYP2D6) enzyme is responsible for interindividual differences in the metabolism of many antipsychotic drugs, but the clinical relevance of polymorphisms in CYP2D6 for response to antipsychotic treatment is relatively unknown. In the Netherlands, clozapine is prescribed only when patients are non-responsive to or intolerant of at least two different antipsychotics. The aim of our study was to determine the association of the CYP2D6 genotype with switching to clozapine, which served as a surrogate outcome marker for treatment response to antipsychotics.

Methods

CYP2D6 genotype was assessed in patients who had been switched to clozapine and compared with antipsychotic users whose treatment regimen included no more than two different antipsychotic drugs and no clozapine. We also performed the analysis in patients who only used CYP2D6-dependent antipsychotics.

Results

A total of 528 patients were included in the study (222 cases, 306 controls). No statistically significant differences were found in the distribution of the polymorphisms among the case and control groups, both in all patients and in only those patients using CYP2D6-dependent antipsychotics. However, a trend was observed, suggesting an inverse association between CYP2D6 genotype and the switch to clozapine. (9.5 vs. 5.1 % poor metabolisers and 1.3 vs. 2.6 % ultrarapid metabolisers in cases vs. controls, respectively).

Conclusions

Although the results of our study suggest that the CYP2D6 phenotype is not a major determining factor for patients to be switched to clozapine treatment, larger studies are warranted with a focus on the clinical consequences of the CYP2D6 ultrarapid metaboliser and poor metaboliser phenotypes.     

Cytochrome P450 polymorphisms and response to antipsychotic therapy

Antipsychotic drugs are used for the treatment of schizophrenia and other related psychotic disorders. The antipsychotics currently available include older or classical compounds and newer or atypical agents. Most antipsychotic drugs are highly lipophilic compounds and undergo extensive metabolism by cytochrome P450 (CYP) enzymes in order to be excreted. There is a wide interindividual variability in the biotransformation of antipsychotic drugs, resulting in pronounced differences in steady-state plasma concentrations and, possibly, in therapeutic and toxic effects, during treatment with fixed doses. Many classical and some newer antipsychotics are metabolized to a significant extent by the polymorphic CYP2D6, which shows large interindividual variation in activity. Other CYPs, especially CYP1A2 and CYP3A4, also contribute to the interindividual variability in the kinetics of antipsychotics and occurrence of drug interactions. No relationship between CYP2D6 genotype or activity and therapeutic effects of classical antipsychotic drugs has been found in the few studies performed. On the other hand, some investigations suggest that poor metabolizers (PMs) of CYP2D6 would be more prone to over-sedation and, possibly, Parkinsonism during treatment with classical antipsychotics, while other studies, mostly retrospective, have been negative or inconclusive. For the newer antipsychotics, such data are lacking. To date, CYP2D6 phenotyping and genotyping appear, therefore, to be clinically useful for dose predicting only in special cases and for a limited number of antipsychotics, while their usefulness in predicting clinical effects must be further explored.     

CYP2D6 genotype and antipsychotic-induced extrapyramidal side effects in schizophrenic patients

OBJECTIVE: In order to evaluate whether poor metabolizers (PM) of debrisoquine are overrepresented among patients with acute dystonic reactions and chronic movement disorders associated with the administration of antipsychotic drugs, the CYP2D6 genotype was determined in schizophrenic patients. METHODS: Allele status for CYP2D6*3, CYP2D6*4, CYP2D6*5, and CYP2D6*6 as well as gene duplication was determined by allele-specific PCR, long-PCR and restriction fragment length polymorphism analysis (RFLP) in 119 schizophrenic patients (99 males and 20 females). All subjects were treated with antipsychotics metabolized, at least partially, by this isozyme. Sixty-three of the patients (52.9%) had a history of extrapyramidal side effects (EPS), while 56 (47.1%) had not experienced such problems (controls). RESULTS: Sixty-five patients (54.6%) were homozygous for a functional CYP2D6*1 allele, 44 (37.0%) were heterozygous for detrimental alleles, and 4 (3.4%), who carried two detrimental alleles, were classified as PM. In six patients (5.0%) duplication of a functional CYP2D6 gene was found, and they were consequently classified as ultrarapid metabolizers (UM). Homo- and heterozygous extensive metabolizers (EM) as well as UM were equally distributed between patients with and without EPS, whereas all the PM had a history of EPS. No significant differences in allele frequencies between the two groups were found. CONCLUSION: Although the results cannot be considered conclusive due to the small number of PM patients in our study, the PM genotype may be a predisposing factor for antipsychotic-induced EPS. Knowledge of the CYP2D6 genotype, before starting antipsychotic therapy, might be useful in identifying subjects at risk of developing EPS.     

Clinical pharmacogenetics in the treatment of schizophrenia]

Numerous investigations on metabolic enzymes, cytochrome P450 (CYP), have been conducted since 1990. In the psychiatric field, the focus has been on CYP2D6, which is a major enzyme involved in metabolism of antidepressants and antipsychotics. Poor metabolizers (deficit metabolizers) for CYP2D6 represent 7% among Caucasians, while they accouut for less than 1% of Asians. The frequency of a mutated allele for CYP2D6*10, which leads to the decrease in CYP2D6 activity, is 40% in Asians. It has been reported that steady-state plasma concentration of haloperidol in subjects with mutated alleles for CYP2D6 is significantly higher than that in subjects without mutated alleles. At the same time, steady-state plasma concentration of risperidone is very different between CYP2D6 genotypes. In addition, several studies suggest that better efficacy or higher scores of side effects are observed in the subjects with mutated alleles for CYP2D6. Recently receptor polymorphism has become a concern and association between clinical response and polymorphism of dopamine and serotonin has been reported. In the dopamine D2, subjects with -141C Ins allele in -141C Ins/Del polymorphism and subjects with A1 allele in Taq1A have a better response to dopamine antagonists. Association between Ser allele and typical antipsychotics and between Gly allele and atypical antipsychotics has been investigated. There are still no data indicating significant association between dopamine D1 and clinical response to antipsychotics. Clinical pharmacogenetical studies from both a pharmacokinetical and a pharmacogynamical point of view are required in order to introduce and practice individualized medicine in psychiatric field easily.     

Antipsychotic-induced extrapyramidal syndromes and cytochrome P450 2D6 genotype: a case-control study

To study the association between polymorphism of the cytochrome P450 2D6 gene (CYP2D6) and the risk of antipsychotic-induced extrapyramidal syndromes, as measured by the use of antiparkinsonian medication.Data for this case-control study were obtained from a psychiatric hospital where newly admitted patients are routinely screened for several CYP2D6 mutant alleles. Cases were patients prescribed antiparkinsonian medication during oral antipsychotic drug treatment in the period September 1994 to August 2000. They were divided into those using an antipsychotic drug the metabolic elimination of which depends on the activity of the CYP2D6 enzyme ('CYP2D6-dependent') and those using other antipsychotic drugs. We formed a control group of antipsychotic drug users for both case groups using a matching ratio of 3 : 1 (controls : cases). Control patients were matched on whether or not their prescribed antipsychotic drug was CYP2D6-dependent. Odds ratios for patients who were slow metabolizers versus patients who were extensive metabolizers were calculated using conditional logistic regression and were adjusted for age, gender, dose and other potential confounding factors.We identified 77 case patients who were prescribed a CYP2D6-dependent antipsychotic drug and 54 case patients who were prescribed non CYP2D6-dependent antipsychotic drugs. Among the case- and control-patients using a CYP2D6-dependent antipsychotic drug, the poor metabolizers were more than four times more likely to start with antiparkinsonian medication than the extensive metabolizers (odds ratio 4.44; 95% confidence interval 1.11-17.68). An increased risk was not observed for patients using non CYP2D6-dependent antipsychotic drugs (odds ratio 1.20; 95% confidence interval 0.21-6.79).Genetically impaired CYP2D6 activity can increase the risk of antipsychotic-induced extrapyrimidal syndromes. Poor metabolizers should have their antipsychotic drug dosage reduced when the metabolism of the prescribed drug depends on CYP2D6 activity or should receive an antipsychotic drug that is not CYP2D6-dependent.