淫羊藿总黄酮对大鼠肝微粒体CYP1A2、CYP3A4和CYP2E1活性的影响

评估淫羊藿总黄酮对大鼠肝细胞色素P450及其主要亚型活性的潜在影响。淫羊藿总黄酮以300mg／kg／d的剂量对SD大鼠进行连续灌胃处理15天，测定肝微粒体中cYP450含量与CYP1A2、CYP3A4和CYP2E1亚型活性，观察淫羊藿总黄酮的效应。CYP1A2的活性用荧光比色法进行测定，CYP3A4和CYP2E1的活性用紫外可见分光光度法测定。淫羊藿总黄酮处理后的大鼠肝脏CYP450含量及CYP1A2、CYP3A4和CYP2E1亚型活性均明显增高，其中CYP1A2和CYP2E1活性升高显著（P〈0．01）。淫羊藿总黄酮对大鼠肝脏CYP450及主要亚型CYP1A2、CYP3A4和CYP2E1活性均有诱导效应。     

己烯雌酚对大鼠CYP2C6和CYP2D2酶的体外抑制作用

目的研究己烯雌酚对大鼠肝微粒体中细胞色素P450同工酶2C6(CYP2C6)和2D2(CYP2D2)的抑制作用。方法采用探针底物法,使用液相色谱-串联质谱检测在不同浓度的己烯雌酚孵育体系中,CYP2C6和CYP2D2的特征性底物双氯芬酸与右美沙芬产生的代谢产物4’-羟基双氯芬酸与右啡烷的浓度。计算得到己烯雌酚对CYP2C6与CYP2D2的半数抑制浓度(IC50)。结果己烯雌酚对大鼠CYP2C6与CYP2D2的IC50值分别为(5.31±0.06)μmol/L,(7.03±0.01)μmol/L。结论己烯雌酚对大鼠CYP2C6与CYP2D2具有中等抑制作用,有必要进一步在体外人体水平对其进行评价以预防潜在的临床药物相互作用。     

丹参-红花药对配伍前后对大鼠肝药酶亚型CYP1A2、CYP2E1和CYP3A4活性的影响

目的 研究丹参、红花药对配伍前后对大鼠肝药酶亚型CYP1A2、CYP2E1和CYP3A4活性的影响。方法 分别选用咖啡因、氯唑沙宗和咪达唑仑作为CYP1A2、CYP2E1和CYP3A4的探针药物。将大鼠随机分为4组,即空白对照组、丹参（1.2 g生药/kg）组、红花（0.4 g生药/kg）组、丹参（1.2 g生药/kg）+红花（0.4 g生药/kg）组,按上述剂量ig给药7 d。于末次给药后30 min,尾iv探针药物咖啡因、氯唑沙宗和咪达唑仑溶液,在不同的时间点取血进行检测;以甲硝唑为内标,采用HPLC法检测探针药物咖啡因、氯唑沙宗和咪达唑仑的量,评价各药物组对大鼠CYP3A4、CYP2E1和CYP1A2活性的影响。结果 与空白对照组比较,丹参组咖啡因、氯唑沙宗和咪达唑仑的清除率（CL）有所增强,曲线下面积（AUC）减少,其半衰期（t_1/2）有减少趋势,但差异均不显著;红花组咖啡因和氯唑沙宗的CL有所降低,但差异不显著,咪达唑仑的CL显著降低（P<0.01）,氯唑沙宗的AUC增加,但差异不显著,咖啡因和咪达唑仑的AUC明显增加（P<0.05、0.01）;丹参+红花组咖啡因和氯唑沙宗的CL明显降低（P<0.05）,曲线下面积（AUC）明显增加（P<0.05）,其t_1/2有延长趋势,但差异不显著。结论 丹参、红花配伍后对CYP450亚型CYP1A2和CYP2E1有抑制作用,这可能是丹参、红花配伍协同增效的作用机制之一。     

甘遂与甘草合用对甘遂毒性成分甘遂萜酯A、甘遂萜酯B代谢的影响

目的研究甘遂与甘草合用对甘遂中毒性成分甘遂萜酯A(Kansuinine A,KA)和甘遂萜酯B(Kansuinine B,KB)代谢的影响。方法将正常对照组、甘草组、甘遂与甘草合用组大鼠给予相应药物处理10 d后,制备肝微粒体。将甘遂的毒性成分KA、KB与各组肝微粒体进行体外共孵育,测定孵育后体系中KA、KB的浓度,用于评价KA、KB的代谢情况。另取正常大鼠肝微粒体,分别加入CYP3A4、CYP2D6、CYP2C9、CYP1A2、CYP2C19的抑制剂红霉素、盐酸苯海拉明、苯溴马隆、西咪替丁和氟康唑,与KA、KB进行体外共孵育,检测孵育后体系中KA、KB的浓度,阐明参与KA、KB代谢的CYP酶亚型。取正常大鼠肝微粒体,分别加入甘草酸与甘草次酸,与KA、KB体外共孵育,测定孵育后体系中KA、KB的浓度,评价甘草酸与甘草次酸对KA、KB代谢的影响。结果甘遂与甘草合用组微粒体中KA、KB的含量明显高于正常对照组和甘遂组,表明甘遂与甘草合用使甘遂中毒性成分KA、KB的代谢受到抑制。与红霉素、盐酸苯海拉明、苯溴马隆、西咪替丁和氟康唑共孵育的微粒体中KA、KB的含量均明显高于空白对照组,表明CYP3A4、CYP2D6、CYP2C9、CYP1A2、CYP2C19均参与了KA、KB的代谢。与甘草酸和甘草次酸共孵育,体系中KA、KB的浓度明显高于空白对照组。CYP3A4、CYP2D6、CYP2C9、CYP1A2表明甘草酸和甘草次酸能够抑制KA、KB的代谢。结论 CYP2C19均可能参与了甘遂毒性成分KA、KB的代谢,甘遂与甘草合用能够抑制CYP3A4、CYP2D6、CYP2C9、CYP1A2及CYP2C19的活性,而使KA、KB的代谢减慢,产生蓄积;另外,甘草中主要成分甘草酸和甘草次酸能够抑制KA、KB的代谢,这可能是甘遂与甘草合用毒性增加的原因之一。     

己烯雌酚对人肝微粒体内CYP3A4和CYP2C9酶的抑制作用

目的:体外实验考察己烯雌酚(DES)对细胞色素P450 3A4(CYP3A4)和细胞色素P450 2C9(CYP2C9)活性的抑制作用,以评佑DES通过抑制这两个重要的细胞色素P450(CYP)亚型而引发药物-药物相互作用的可能性.方法:混合人肝微粒体与不同浓度的DES(或阳性抑制剂),CYP3A4或CYP2C9的探针...     

川阿格雷对大鼠肝微粒体CYP1A2、CYP3A4和CYP2E1活性的影响

川阿格雷是基于传统中药机制,运用现代技术合成的新一代抗血小板药物,适用于预防和治疗因血小板高聚集态引起的心、脑及其他动脉的循环障碍疾病,具有很好的开发价值,而药物的代谢特性是药物研发的重要内容。有研究表明,CYP450酶可被药物等外源物诱导和抑制,导致其含量和活性的改变,从而直接影响药物在体内的血药浓度、动力     

CYP2C19基因型和CYP2C9对人肝微粒体中氟西汀N-去甲基代谢的影响(英文)

目的:本实验旨在研究CYP2C19基因型人肝微粒体中氟西汀N-去甲基代谢的酶促动力学特点并鉴定参与此代谢途径的细胞色素P-450酶。方法:测定基因型CYP2C19肝微粒体中去甲氟西汀形成的酶促动力学。鉴定氟西汀N-去甲基酶活性与细胞色素P-450 2C9,2C19,1A2和2D6酶活性的相关性,同时应用各种细胞色素P-450酶的选择性抑制剂和化学探针进行抑制实验,从而确定参与氟西汀N-去甲基代谢的细胞色素P-450酶。结果:去甲氟西汀生成的酶促动力学数据符合单酶模型,并具有Michaelis-Menten动力学特征。当底物浓度为氟西汀25μmol/L和100μmol/L时,去甲氟西汀(N-FLU)的生成率分别与甲磺丁脲3-羟化酶活性显著相关(r_1=0.821,P_1=0.001;r_2=0.668,P_2=0.013),当底物浓度为氟西汀100μmol/L时,N-FLU的生成率与S-美芬妥因4’-羟化酶活性显著相关(r=0.717,P=0.006)。PM肝微粒中磺胺苯吡唑和醋竹桃霉素对氟西汀N-去甲基代谢的抑制作用显著大于EM(73％vs 45％,P<0.01)。结论:在生理底物浓度下,CYP2C9是催化人肝微粒体中氟西汀N-去甲基代谢的主要CYP-450酶;而高底物浓度时,以CYP2C19的作用为主。     

大鼠肝微粒体代谢研究槲皮素对CYP1A2,CYP2E1,CYP3A2活性的影响及抑制机制

目的体外代谢研究槲皮素对大鼠肝CYP1A2,CYP2E1,和CYP3A2活性的影响。研究其抑制强度及抑制机制。方法QU与底物共同温孵,HPLC检测底物特定的代谢产物生成量的变化反映对应亚酶的活性变化。比较槲皮素与酮康唑,红霉素在相同浓度下对CYP3A2的抑制能力强弱。不同浓度槲皮素对CYP3A2和CYP2E1底物代谢产物生成双倒数直线的影响初步分析槲皮素可能的抑制机制。结果各HPLC检测方法线性相关系数均>0.9991,RSD均<8.4%,回收率91.1%-107.6%。槲皮素在体外0～8μmol·L-1诱导大鼠肝微粒体CYP1A2的活性达338.1%,并抑制CYP2E1(49.2%),和CYP3A2(60.3%)。槲皮素对CYP3A2的抑制能力在酮康唑和红霉素之间。槲皮素竞争性抑制CYP3A2右美沙芬N脱甲基反应,非竞争性抑制CYP2E1氯唑沙宗6羟化反应。结论槲皮素对多个CYP450亚酶有抑制作用,它是有效的CYP3A竞争性抑制剂。做为黄酮类植物雌激素,槲皮素有分子结构的优势亦有对CYP450酶调控能力而具有未来抗肿瘤药物研究的潜力。     

冰片对大鼠体内CYP2D诱导作用研究

冰片是传统中药,近年来许多文献报道冰片能提高其他药物的生物利用度,促进其他药物进入血脑屏障,因而冰片与其他药物合用可能产生的药物相互作用受到高度重视,但冰片对肝脏细胞色素P450酶的影响却鲜有报道。本文研究了雄性Wistar大鼠连续灌胃冰片一周对大鼠肝脏CYP2D表达与活性以及对CYP2D探针底物右美沙芬大鼠体内药代动力学的影响。结果表明,冰片(33、100和300 mg·kg-1·d-1)给药一周对大鼠肝脏CYP2D1 m RNA和蛋白表达无明显影响,但却显著诱导了CYP2D活性(P<0.05),分别达到1.71、1.97和2.89倍。此外,与对照组相比,冰片(300 mg·kg-1·d-1)预给药一周组右美沙芬的达峰浓度Cmax降低了10.6%(P>0.05),曲线下面积AUC0-∞减少了27.5%(P<0.01),清除率CL/F增大了41.1%(P<0.01),表观分布容积Vz/F增大了23.1%(P>0.05),表明冰片预给药一周能明显加速CYP2D探针底物右美沙芬的体内清除。由于冰片对大鼠肝脏CYP2D活性的诱导作用,提示当冰片与CYP2D底物药物共用时,可能存在发生代谢性相互作用的风险。     

丝裂霉素C在体外和体内对大鼠肝脏CYP2D1/2,CYP2C11和CYP1A2活性的影响

目的研究丝裂霉素C(MMC)在体外和体内对大鼠肝脏CYP2D1/2,CYP2C11和CYP1A2活性的影响。方法用诱导剂和抑制剂分别在体内和体外调节大鼠肝脏P450同工酶活性，并用HPLC检测3种同工酶各自底物的特定代谢产物，以计算同工酶活性。结果在体外, MMC可以使地塞米松诱导的大鼠肝脏微粒体CYP2D1/2,CYP2C11和CYP1A2活性分别抑制(19±6)%(P<0.05),(85±10)％(P<0.01)和(36±6)%(P<0.05)，并使β-萘黄酮诱导的CYP1A2活性降低(58±6)%(P<0.01)。在体内，以20% LD₅₀的剂量连续3 d或6 d腹腔注射MMC 对大鼠肝脏CYP2D1/2，CYP2C11和CYP1A2活性的影响无统计学差异。结论在体外MMC可以抑制大鼠肝微粒体CYP2D1/2，CYP2C11和CYP1A2的活性，但在体内对这3种细胞色素P450同工酶活性的影响无统计学差异。     

甘草与大戟甘遂芫花配伍对大鼠肝脏细胞色素P4501A2酶活性的影响

目的研究甘草与大戟、甘遂、芫花合用对细胞色素P450(CYP)1A2酶活性的影响。方法采用高效液相色谱法测定CYP1A2活性。结果单用甘草诱导CYP1A2的酶活性;大戟、甘遂、芫花单用抑制CYP1A2的酶活性;甘草与大戟、甘遂、芫花合用后抑制了CYP1A2的酶活性。结论甘草与大戟、甘遂、芫花合用对CYP1A2酶活性的抑制作用主要是由大戟、甘遂、芫花引起的。     

Effect of eurycomanone on cytochrome P450 isoforms CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2C19, CYP2E1 and CYP3A4 in vitro

Eurycomanone, an active constituent isolated from Eurycoma longifolia Jack, was examined for modulatory effects on cytochrome P450 (CYP) isoforms CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2C19, CYP2E1 and CYP3A4 using in vitro assays. The IC₅₀ value was determined to assess the potencies of modulation for each CYP isoform. Our results indicated that eurycomanone did not potently inhibit any of the CYP isoforms investigated, with IC₅₀ values greater than 250 μg/ml. Hence there appears to be little likelihood of drug–herb interaction between eurycomanone or herbal products with high content of this compound and CYP drug substrates via CYP inhibition.     

Effect of chronic disulfiram administration on the activities of CYP1A2, CYP2C19, CYP2D6, CYP2E1, and N-acetyltransferase in healthy human subjects

AIMS: Short-term disulfiram administration has been shown to selectively inhibit CYP2E1 activity but the effects of chronic disulfiram administration on the activities of drug metabolizing enzymes is unclear. The purpose of this study was to evaluate the effects of disulfiram given for 11 days on selected drug metabolizing enzyme activities. METHODS: Seven healthy volunteers were given disulfiram 250 mg daily for 11 days. Activities of the drug metabolizing enzymes CYP1A2, CYP2C19, CYP2D6, CYP2E1 and N-acetyltransferase were determined using the probe drugs caffeine, mephenytoin, debrisoquine, chlorzoxazone, and dapsone, respectively. Chlorzoxazone was administered before disulfiram administration and after the second and eleventh doses of disulfiram, while the other probe drugs were given before disulfiram administration and after the eleventh disulfiram dose. RESULTS: Disulfiram administration markedly inhibited chlorzoxazone 6-hydroxylation by more than 95%, but did not affect metabolism of debrisoquine or mephenytoin. Caffeine N3-demethylation was decreased by 34% (P < 0.05). Monoacetyldapsone concentrations were markedly elevated by disulfiram administration resulting in a nearly 16-fold increase in the dapsone acetylation index, calculated as the plasma concentration ratio of monoacetyldapsone to dapsone. CYP-mediated dapsone N-hydroxylation was not significantly altered. CONCLUSIONS: These data suggest that disulfiram-mediated inhibition is predominantly selective for CYP2E1. The magnitude of CYP2E1 inhibition was similar after both acute and chronic disulfiram administration. The effects on caffeine N3-demethylation (CYP1A2) and dapsone metabolism suggest that chronic disulfiram administration may affect multiple drug metabolizing enzymes, which could potentially complicate the use of chronically administered disulfiram as a diagnostic inhibitor of CYP2E1.     

Frequency distribution of high risk alleles of CYP2C19, CYP2E1, CYP3A4 genes in Haryana population

The genotype of an individual can significantly influence the disposition of a chemical, and determine their susceptibility to its toxicity. Many enzymes involved in either activation or detoxification of chemical carcinogen metabolism are polymorphically expressed, with the alleles presenting different enzymatic activities and some of them having been associated with susceptibility to cancer. Cytochrome P450 (P450 or CYP) constitutes the most important phase I enzyme group responsible for the metabolism of endogenous and exogenous (xenobiotics) substances. The present study was aimed to analyze the frequencies of commonly known polymorphisms of human xenobiotic metabolizing genes (XMG) in the Haryana State population of North India. The study was conducted in 308 healthy Haryana volunteers. DNA was extracted from leucocytes and the genetic polymorphisms in CYP2C19*2, CYP2C19*3, CYP2E1*5B and CYP3A4*1B were determined by digesting the PCR Product with restriction enzymes BamHI, SmaI, PstI and PstI respectively. The genotype frequencies of CYP2C19*2, CYP2C19*3, CYP2E1*5B, and CYP3A4*1B were found to be 22.0%, 0.0%, 2.11% and 2.0% respectively. The North Indian population which is known to be Caucasoid Aryans is ethnically different from South Indians known as Caucasoid Dravidians but no significant difference in genetic polymorphism was found.     

CYP2C19 polymorphism effect on phenobarbitone

OBJECTIVE: The aim of this study was to clarify the effect of genetic polymorphisms of CYP2C19 on the pharmacokinetics of phenobarbitone (PB) using a nonlinear mixed-effects model (NONMEM) analysis in Japanese adults with epilepsy. METHODS: A total of 144 serum PB concentrations were obtained from 74 subjects treated with both PB and phenytoin but without valproic acid. All patients were classified into three groups by CYP2C19 genotyping: G1, G2 and G3 were homozygous for the wild type of CYP2C19 (*1/*1), heterozygous extensive metabolizers (EMs), (*1/*2 or *1/*3), and poor metabolizers (PMs), (*2/*2, *2/*3), respectively. All data were analyzed using NONMEM to estimate pharmacokinetic parameters of PB with respect to the CYP2C19 genotype. RESULTS: Thirty-three patients belonged to G1 (44.6%), 35 to G2 (47.3%), and 6 to G3 (8.1%). The total clearance (CL) of PB significantly decreased by 18.8% in PMs (G3) relative to EMs (G1 and G2). The CL tended to be lower in G2 than in G1. CONCLUSION: In this study, we first demonstrated the effect of the CYP2C19 polymorphism on pharmacokinetics of PB by genotyping. The contribution of other metabolic enzymes in the metabolism of PB in humans remains to be elucidated; however, it appears that the disposition of PB is mediated in part by this enzyme. The estimated population clearance values in the three genotype groups can be used to predict the PB dose required to achieve an appropriate serum concentration in an individual patient.     

Polymorphisms of drug-metabolizing enzymes CYP2C9, CYP2C19, CYP2D6, CYP1A1, NAT2 and of P-glycoprotein in a Russian population

Objective The frequency of functionally important mutations and alleles of genes coding for xenobiotic metabolizing enzymes shows a wide ethnic variation. However, little is known of the frequency distribution of the major allelic variants in the Russian population.Methods Using polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP) genotyping assays and the real-time PCR with fluorescent probes, the frequencies of functionally important variants of the cytochromes P₄₅₀ (CYP) 2C9, 2C19, 2D6, 1A1 as well as arylamine N-acetyltransferase 2 (NAT2) and P-glycoprotein (MDR1) were determined in a sample of 290 Russian volunteers derived from Voronezh area.Results CYP2C9*2 and *3 alleles were found with allelic frequencies of 10.5% and 6.7%, respectively. The novel intron-2 T>C mutation at exon 2 +73 bp occurred in 24.8% of alleles. CYP2C19*2 and *3 alleles occurred in 11.4% and 0.3%, respectively. Six persons (2.1%) carried two of these CYP2C19 alleles responsible for poor metabolizing activity. Of all subjects, 5.9% were CYP2D6 poor metabolizers, whereas 3.4% were addressed to ultra-rapid metabolizers (CYP2D6*1×2/*1). The CYP1A1*2A allele was found in 4.7%, *2B in 5.0%, *4 in 2.6%, and the 5-mutations –3219C>T, –3229G>A, and the novel –4335G>A in 6.0%, 2.9% and 26.0% of alleles, respectively. Genotyping of eight different single nucleotide polymorphisms in the NAT2 gene provided in 58.0% a genotype associated with slow acetylation. The MDR1 triple variants G2677T and G2677A in exon 21 had an allelic frequency of 41.9% and 3.3%, respectively, and the variant C3435T in exon 26 one of 54.3%. Frequencies of functionally important haplotypes were calculated.Conclusion The overview of allele distribution of important xenobiotic-metabolizing enzymes among a Russian population shows similarity to other Caucasians. The data will be useful for clinical pharmacokinetic investigations and for drug dosage recommendations in the Russian population.     

Trade Herbal Products and Induction of CYP2C19 and CYP2E1 in Cultured Human Hepatocytes

Abstract: The aim of this study was to evaluate in vitro the dose‐dependent induction potential of six commonly used trade herbal products on CYP2C19 and CYP2E1 metabolic activities in cultured human hepatocytes. S‐mephenytoin and chlorzoxazone were used as specific CYP substrates, respectively, and rifampicin was used as a positive induction control for both enzymes. The hepatocytes were exposed to herbal extracts in increasing and biological relevant concentrations for 72 hrs and CYP substrate metabolites were quantified by validated HPLC methodologies. The major findings were that St John's wort was the most potent CYP‐modulating herb, showing a dose‐dependent induction/inhibition of both CYP2C19 and CYP2E1, with induction at low dosages and inhibition at higher. Ginkgo biloba showed an induction/inhibition profile towards CYP2C19 which was similar but weaker than that observed for St John's wort. If cooperative mechanisms are involved is still an open question. Common sage induced CYP2C19 in a log‐linear dose‐dependent manner with increasing concentrations. Common valerian was a weak inducer of CYP2C19, while horse chestnut and cone flower were characterized as non‐inducers of CYP2C19. Only St John's wort showed an inductive effect towards CYP2E1. In addition to St John's wort, Gingko biloba and common sage should be considered as possible candidates for clinically relevant drug‐herb interactions with selected CYP2C19 substrates.     

Pharmacogenetics of P450 oxidoreductase: effect of sequence variants on activities of CYP1A2 and CYP2C19

OBJECTIVES: All microsomal cytochrome P450s enzymes, including those that metabolize the majority of clinically used drugs, require electron transfer through P450 oxidoreductase (POR). Mutations in human POR cause altered steroidogenesis and congenital malformations, but the clinical effects on drug metabolism are unclear. We examined the effects of POR sequence variants on two drug-metabolizing P450 enzymes, CYP1A2 and CYP2C19. METHODS: Our previous sequencing of the human POR gene in POR-deficient patients and in 842 normal individuals identified 35 sequence variants. We expressed these 35 POR sequence variants in bacteria, reconstituted them with the CYP enzymes in vitro, and assayed their activities with human CYP1A2 and CYP2C19. RESULTS: POR variants affected the activities of these enzymes to different extents. Disease-causing POR mutations A287P and R457H diminished catalysis by CYP1A2 and CYP2C19 to barely detectable levels. POR A503V, a polymorphism found in 28% of alleles in the normal population, had 85% of wild-type activity with CYP1A2 and 113% of wild-type activity with CYP2C19. Q153R, a disease-causing mutation that severely impaired steroidogenic activity and cytochrome c reduction, increased the activity of CYP1A2 to 144% and CYP2C19 activity to 284% of control. CONCLUSION: The activity of individual POR mutants may vary greatly depending on the electron recipient used to assay activity. Thus, the activity of a POR mutant to support catalysis by a particular P450 enzyme cannot be predicted by the activity of that POR mutant in an assay with a different P450 or with cytochrome c.     

Pharmacogenomics of CYP2A6, CYP2B6, CYP2C19, CYP2D6, CYP3A4, CYP3A5 and MDR1 in Vietnam

Aim  The aim of this study was to obtain pharmacogenetic data in a Vietnamese population on genes coding for proteins involved in the elimination of drugs currently used for the treatment of malaria and human immunodeficiency virus/acquired immunodeficiency syndrome. Method  The main polymorphisms on the cytochrome P450 (CYP) genes, CYP2A6, CYP2B6, CYP2C19, CYP2D6, CYP3A4 and CYP3A5, and the multi-drug resistance 1 gene (MDR1) were genotyped in 78 healthy Vietnamese subjects. Pharmacokinetic metrics were available for CYP2A6 (coumarin), CYP2C19 (mephenytoin), CYP2D6 (metoprolol) and CYP3As (midazolam), allowing correlations with the determined genotype. Results  In the CYP2 family, we detected alleles CYP2A6*4 (12%) and *5 (15%); CYP2B6*4 (8%), *6 (27%); CYP2C19*2 (31%) and *3 (6%); CYP2D6*4, *5, *10 (1, 8 and 44%, respectively). In the CYP3A family, CYP3A4*1B was detected at a low frequency (2%), whereas CYP3A5 *3 was detected at a frequency of 67%. The MDR1 3435T allele was present with a prevalence of 40%. Allele proportions in our cohort were compared with those reported for other Asian populations. CYP2C19 genotypes were associated to the S-4′-OH-mephenytoin/S-mephenytoin ratio quantified in plasma 4 h after intake of 100 mg mephenytoin. While CYP2D6 genotypes were partially reflected by the α-OH-metroprolol/metoprolol ratio in plasma 4 h after dosing, no correlation existed between midazolam plasma concentrations 4 h post-dose and CYP3A genotypes. Conclusions  The Vietnamese subjects of our study cohort presented allele prevalences in drug-metabolising enzymes that were generally comparable with those reported in other Asian populations. Deviations were found for CYP2A6*4 compared to a Chinese population (12 vs. 5%, respectively; P = 0.023), CYP2A6*5 compared with a Korean population (15 vs. <1%, respectively; P < 0.0001), a Malaysian population (1%; P < 0.0001) and a Chinese population (1%; P < 0.0001); CYP2B6*6 compared with a Korean population (27 vs. 12%; P = 0.002) and a Japanese population (16%; P = 0.021). Pharmacokinetic metrics versus genotype analysis reinforces the view that the predictive value of certain globally common variants (e.g. CYP2D6 single nucleotide polymorphisms) should be evaluated in a population-specific manner.