中国沈阳地区汉族冠心病患者CYP2C19基因多态性分布特征

目的探讨沈阳地区汉族冠心病(coronary heart disease,CHD)患者细胞色素P450 2C19(CYP2C19)基因多态性分布特征。方法选取2016年1月～2018年1月于北部战区总医院(原沈阳军区总医院)入院接受治疗的冠心病患者2 748例,应用聚合酶链反应微阵列芯片杂交方法检测患者氯吡格雷代谢相关的CYP2C19基因型。根据性别、年龄因素对患者进行分组。采用四格表资料的χ~2检验,R×C表资料的χ~2检验比较各组间冠心病患者氯吡格雷代谢相关的CYP2C19*1,*2,*3基因型,*2,*3等位基因频率,及氯吡格雷代谢型的分布差异。结果沈阳地区汉族冠心病患者CYP2C19*1/*1,CYP2C19*1/*2,CYP2C19*1/*3,CYP2C19*2/*2,CYP2C19*3/*3和CYP2C19*2/*3发生率分别为41.7%,39.3%,5.8%,9.8%,0.4%和3.0%;CYP2C19*2,CYP2C19*3等位基因频率分别为31.0%和4.8%;氯吡格雷快代谢型(EM),氯吡格雷中间代谢型(IM),氯吡格雷慢代谢型(PM)发生率分别为41.7%,45.1%和13.2%。根据性别分组,患者CYP2C19*2,*3等位基因,氯吡格雷代谢型,CYP2C19的6种基因型在不同性别冠心病患者中的分布差异均无统计学意义(χ~2=0.032～9.205,均P0.05)。根据年龄分组45岁,45～59岁,60～75岁,75岁,患者CYP2C19*2,*3等位基因,CYP2C19的6种基因型在不同年龄冠心病患者中的分布差异均有统计学意义(χ~2=17.718～48.772,均P≤0.001),氯吡格雷代谢型在不同年龄冠心病患者中的分布差异无统计学意义(χ~2=4.442,P=0.617)。结论沈阳地区汉族冠心病患者CYP2C19的6种基因型,CYP2C19*2,*3等位基因分布与沈阳地区汉族冠心病患者性别差异无关,与年龄分层密切相关。     

陕西地区CYP2C19基因多态性在不同性别、年龄、民族冠心病患者中的分布特征以及与国内其他地区的对比分析

目的探讨陕西地区冠心病治疗患者CYP2C19基因多态性分布情况。方法选取该院冠心病治疗患者4248例,检测CYP2C19的基因型,统计等位基因及代谢表型分布特征,并对比不同地区汉族和其他民族等位基因及代谢表型分布差异。结果CYP2C19*1、CYP2C19*2和CYP2C19*33种等位基因的频率分别为64.67%、30.65%、4.68%;快代谢型(*1/*1)1749例,发生率41.17%,中间代谢型(*1/*2、*1/*3)1996例,发生率46.99%,慢代谢型(*2/*2、*2/*3、*3/*3)503例,发生率11.84%;不同性别之间基因型及代谢型分布差异无统计学意义(P>0.05);不同年龄段患者CYP2C19基因型分布差异无统计学意义(P>0.05),等位基因分布差异有统计学意义(P<0.05);我国不同地区汉族人群等位基因分布差异有统计学意义(P<0.05),代谢型分布差异无统计学意义(P>0.05);不同民族等位基因及代谢型分布差异均有统计学意义(P<0.05)。结论陕西地区冠心病患者基因型主要以CYP2C19*1/*2为主,代谢表型主要以中间代谢型为主,可以评估其氯吡格雷抵抗风险,为患者制定个体化的抗血小板治疗方案。     

东莞地区汉族冠心病患者CYP2C19基因多态性分布特征分析

目的探讨东莞地区汉族冠心病患者CYP2C19基因多态性分布特征。方法选取该院2016年9月至2019年1月收治的800例汉族冠心病患者作为研究对象,采用等位基因特异PCR技术对患者CYP2C19基因多态性进行检测,了解CYP2C19基因多态性分布情况,并根据患者的年龄、性别进行分组分析。结果 CYP2C19基因型中*1/*1出现频率为38.50%,*1/*2频率为40.00%,*1/*3频率为6.38%,*2/*2频率为11.75%,*2/*3频率为3.00%,*3/*3频率为0.37%;其中快代谢型为38.50%、中代谢型为46.38%、慢代谢型为15.12%;等位基因分布中CYP2C19*1占61.69%,CYP2C19*2占33.25%,CYP2C19*3占5.06%。不同年龄、性别、患者CYP2C19各基因多态性分布虽存在一定的差异,但差异无统计学意义(P>0.05)。结论东莞地区汉族人群冠心病患者CYP2C19基因型中以快代谢型与中代谢型为主,基因分布以CYP2C19*1占比较高,不同性别、年龄患者CYP2C19基因型间差异不明显。     

广东佛山地区冠心病患者CYP2C19基因多态性分析

目的探讨广东佛山地区冠心病患者CYP2C19基因的多态性分布特征。方法采用DNA微阵列芯片法对1 083例冠心病患者进行CYP2C19基因分型,比较不同地区人群之间CYP2C19基因多态性分布的差异。结果在1 083份检测标本中,CYP2C19*1、*2及*3等位基因的频率分别为63.57%、31.12%、5.31%;CYP2C19分3种代谢型,快代谢型(*1/*1)占40.90%,中间代谢型(*1/*2、*1/*3)占45.34%,慢代谢型(*2/*2、*2/*3、*3/*3)占13.76%。佛山地区代谢型分布与广州和东莞地区相似,而与汕头地区却差异有统计学意义(P0.05)。结论佛山地区冠心病患者中有较多的CYP2C19代谢功能缺失基因,临床用药前应加强患者基因检测,调整用药剂量或种类,实现精准治疗。     

急性心肌梗死患者CYP2C19基因多态性分布及氯吡格雷治疗对PCI术后不良心血管事件和再狭窄的影响

目的:检测急性心肌梗死患者CYP2C19基因多态性分布情况,并分析氯吡格雷治疗对PCI术后不良心血管事件和再狭窄的影响。方法:选取我院2018-01—2019-06期间收治的214例行PCI术的急性心梗患者作为研究对象。所有患者PCI术后均给予阿司匹林和氯吡格雷治疗,采用PCR测定患者全血CYP2C19基因分布,比较患者CYP2C19基因型特征,分析其与发生心血管不良事件及再狭窄的关系。结果:214例患者CYP2C19*1、*2、*3等位基因分布频率分别为66.36%、29.21%及4.43%;快代谢型的频率为44.86%,中代谢型的频率为42.99%,慢代谢型的频率为12.15%。其中,发生心血管不良事件组患者快代谢基因型出现的频率为9.76%,中代谢型基因出现的频率为53.65%,慢代谢基因型出现频率为36.59%(P0.05);且发生心血管不良事件*1等位基因出现频率为36.59%,显著低于未发生组(P0.05),而*2等位基因及*3等位基因出现频率分别为51.22%及12.19%,均显著高于未发生组,差异有统计学意义(P0.05)。单因素分析发现患者再狭窄与氯吡格雷抵抗有关(P0.05)。结论:急性心梗患者PCI术后发生心血管不良事件患者CYP2C19基因突变率较高,主要以中代谢及慢代谢基因型为主,且患者CYP2C19*2和CYP2C19*3基因突变是导致预后发生不良心血管事件及再狭窄的重要原因。     

四川地区冠心病患者CYP2C19基因多态性检测

目的检测四川地区冠心病患者CYP2C19基因的多态性,分析基因型与性别、年龄及临床分型之间的相关性。方法采用DNA微阵列芯片法检测131例被确诊为冠心病患者的CYP2C19基因型,结合患者的性别、年龄、临床分型进行分组,探讨这些因素与CYP2C19基因多态性的相关性。结果 131例冠心病患者中,有5种基因型被检测到,分别为CYP2C19*1/*1(636GG,681GG)、CYP2C19*1/*2(636GG,681GA)、CYP2C19*1/*3(636GA,681GG)、CYP2C19*2/*2(636GG,681AA)、CYP2C19*2/*3(636GA,681GA)。分布频率分别为53例(40.5%)、54例(41.2%)、6例(4.6%)、13例(9.9%)、5例(3.8%),而CYP2C19*3/*3(636AA,681GG)未被检测到。不同性别冠心病患者CYP2C19的基因型、等位基因频率差异无统计学意义(P0.05);不同性别的代谢型患者,其CYP2C19的基因型分布差异具有统计学意义(χ~2=6.527,P=0.038)。不同年龄和临床分型冠心病患者CYP2C19的基因型、等位基因频率、代谢型分布差异无统计学意义(P0.05)。结论冠心病患者的CYP2C19基因型分布、等位基因频率分布与性别、年龄和疾病临床分型无关。     

1043例汉族双相情感障碍患者CYP2C19基因多态性及代谢表型分析

目的探讨汉族双相情感障碍患者CYP2C19基因多态性及代谢表型的分布,为临床合理用药提供理论参考和指导。方法以DNA微阵列技术检测1 043例双相情感障碍患者的CYP2C19基因多态性及代谢表型(快代谢型,中等代谢型,慢代谢型),用基因计数法计算基因型频率和等位基因频率,同时分析基因多态性发生频率与性别的相关性。结果所有检测对象中,CYP2C19*1/*1、*1/*2、*1/*3、*2/*2、*2/*3、*3/*3基因型的频率分别为40.6%、40.5%、5.2%、9.9%、3.4%、0.5%;CYP2C19基因快代谢型、中等代谢型、慢代谢型3种代谢表型所占比例分别为40.5%、45.8%、13.7%;不同性别之间CYP2C19基因型及代谢表型差异无统计学意义(P0.05)。结论汉族双相情感障碍人群CYP2C19基因多态性以*1/*1及*1/*2为主,681位点的变异率高于636位点,检测CYP2C19基因多态性及代谢表型有助于临床合理用药。     

基质辅助激光解吸电离飞行时间质谱技术检测药物代谢酶基因多态性平台的建立

目的 建立基于基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)技术检测患者体内药物代谢酶基因多态性的平台。方法 选取2013年10月～2014年6月在北京协和医院门诊就诊患者53例EDTA抗凝外周血,提取全血基因组DNA,用MALDI-TOF-MS技术检测53例患者药物代谢酶基因CYP2C9*2(rs1799853),CYP2C9*3(rs1057910),CYP2C19*2(rs4244285),CYP2C19*3(rs4986893),CYP2C19*4(rs28399504),CYP2C19*5(rs56337013)和CYP2C19*17(rs12248560)的单核苷酸多态性(SNP)位点,并用Sanger测序法进行验证。结果 用 MALDI-TOF-MS 技术可以同时完成53份样本,2个药物代谢酶基因,7个SNP位点的检测。53例患者中,发现CYP2C19*2(rs4244285)AG型25例,AA型6例,GG型22例,A等位基因频率为34.9%。CYP2C19*3(rs4986893)AG型4例,GG型49例,A等位基因频率为3.8%。CYP2C9*3(rs1057910)CA型5例,AA型48例,C等位基因频率为4.7%。未发现 CYP2C9*2(rs1799853),CYP2C19*4(rs28399504),CYP2C19*5(rs56337013)和CYP2C19*17(rs12248560)位点突变。经与Sanger测序法比较,两种检测方法结果的符合率为100%。结论 成功建立MALDI-TOF-MS技术检测药物代谢酶基因多态性的平台,该平台具有高通量、准确的特点,对个性化用药治疗具有重要的临床应用价值。     

武汉地区冠心病患者氯吡格雷药物代谢相关基因CYP2C19的多态性分布分析

目的 探讨武汉地区冠心病介入患者氯吡格雷代谢相关基因CYP2C19多态性的分布。方法 选取2014年1月～12月武汉大学人民医院心内科进行介入治疗(PCI)的316例冠心病患者作为研究对象。通过基因芯片法检测氯吡格雷代谢相关的CYP2C19*1,*2,*3基因,并将患者按CYP2C19基因型别分为不同代谢类型:强代谢型(*1/*1),中间代谢型(*1/*2,*1/*3),弱代谢型(*2/*2,*3/*3,*2/*3)。结果 根据CYP2C19基因多态性位点功能代谢分型,携带CYP2C19*1的强代谢型(*1/*1)占43.4%,携带CYP2C19*2或*3的中间代谢型(*1/*2和*1/*3)及弱代谢型(*2/*2,*2/*3和*3/*3)分别占42.4%,14.2%。不同性别在CYP2C19基因分型上差异无统计学意义。结论 武汉地区冠心病介入患者中分布有较多的CYP2C19氯吡格雷代谢功能缺失基因。     

咸阳地区经皮冠状动脉介入术后冠心病患者CYP2C19基因多态性分析

目的探讨咸阳地区经皮冠状动脉介入术(PCI)后冠心病患者细胞色素氧化酶P450 2C19(CYP2C19)基因多态性分布情况,为指导临床个性化抗血小板治疗提供理论依据。方法选取2017年12月至2019年6月于该院心血管中心行PCI并服用氯吡格雷进行抗血小板治疗的冠心病患者279例作为研究对象,采用实时荧光聚合酶链反应探针检测CYP2C19的基因型。结果CYP2C19基因多态性分布特点:CYP2C19正常代谢型(*1/*1)109例,占39.07%;CYP2C19中间代谢型(*1/*2、*1/*3)127例,占45.52%;CYP2C19慢代谢型(*2/*3、*2/*2、*3/*3)43例,占15.41%。咸阳地区冠心病患者CYP2C19代谢型分布与我国其他地区差异无统计学意义(χ2=1.954,P0.05),正常代谢型、中间代谢型占比较高。结论通过基因检测有助于个性化使用抗血小板聚集药物或调整抗血小板聚集药物剂量,减少因用药不当造成的血栓事件发生。     

冠心病患者CYP2C19基因多态性及临床不良事件发生与氯吡格雷抵抗的关系

目的通过分析经皮冠状动脉介入治疗(PCI)术后冠心病患者的CYP2C19基因型结果、临床相关危险因素和主要心血管不良事件发生情况与氯吡格雷抵抗的关系,探讨影响氯吡格雷抵抗发生、发展的因素,为临床治疗提供有效依据。方法收集2017年1月至2018年12月该院收治并进行过基因检测的346例冠心病患者资料,分析其CYP2C19基因型和代谢型分布特征,筛选出251例使用氯吡格雷的PCI术后冠心病患者,进行血小板聚集功能试验检测,根据血小板最大聚集率(MAR)分为氯吡格雷敏感组(MAR<50%)和氯吡格雷抵抗组(MAR≥50%)。利用荧光PCR法进行CYP2C19基因多态性检测,根据基因型结果分为快代谢型(*1/*1)、中代谢型(*1/*2、*1/*3)和慢代谢型(*2/*2、*2/*3、*3/*3)。比较氯吡格雷抵抗组与氯吡格雷敏感组不同代谢型的患者比例、相关危险因素情况及临床心血管不良事件发生情况。结果慢代谢型患者的MAR较中代谢型、快代谢型患者高,差异均有统计学意义(P<0.05)。入选的251例患者中,氯吡格雷抵抗组CYP2C19代谢型分别为快代谢型38例(34.5%)、中代谢型57例(51.8%)、慢代谢型15例(13.6%),氯吡格雷抵抗组与氯吡格雷敏感组在快代谢型中的患者比例差异有统计学意义(P<0.05)。氯吡格雷抵抗组的高血压患者比例(91.8%)与氯吡格雷敏感组(63.8%)比较,差异有统计学意义(P<0.05)。氯吡格雷抵抗组临床心血管不良事件发生率(94.5%)高于氯吡格雷敏感组(84.4%),差异有统计学意义(P <0.05)。结论CYP2C19基因突变和高血压可能是氯吡格雷抵抗发生的两个重要影响因素,并且氯吡格雷抵抗增加了PCI术后冠心病患者临床心血管不良事件发生的风险。     

基于武汉地区PCI术后患者CYP2C19基因多态性指导氯吡格雷个体化用药的研究

目的 研究CYP2C19基因多态性,分析经皮冠状动脉介入治疗(PCI)术后氯吡格雷中、慢代谢患者个体化用药的疗效差异,为PCI术后患者个体化用药提供参考依据.方法 使用荧光定量PCR法测定该院328例PCI术后患者CYP2C19基因型,分析年龄、性别与CYP2C19基因多态性的关系及不同地区汉族冠心病患者代谢表型差异,...     

荧光PCR检测CYP2C19基因分型与氯吡格雷临床疗效的相关性研究

目的通过分析CYP2C19基因型与ADP抑制率之间的关系,探讨CYP2C19基因分型与氯吡格雷抗凝治疗效果的关系。方法选取急性冠脉综合征（ACS）并成功接受经皮冠状动脉介入治疗术（PCI）的患者55例,收集患者EDTA抗凝静脉血提取血液基因组DNA,用实时荧光PCR方法分析CYP2C19基因型,测定每名患者ADP抑制率,用统计学方法分析CYP2C19不同基因型患者ADP抑制率的差异。结果所有入组患者根据基因型不同分为快代谢组占49.09%（27/55）,中等代谢组占38.19%（21/55）,慢代谢组占12.73%（7/55）。三组ADP抑制率比较,两两相比差异均有统计学意义（P〈0.01）。结论 CYP2C19基因多态性与氯吡格雷抵抗存在关联,快代谢型患者PCI术后服用氯吡格雷疗效好于携带基因突变的患者,慢代谢型患者PCI术后服用氯吡格雷疗效差。     

CYP2C19基因多态性在江苏及其周边地区汉族人群的调查研究

目的探讨CYP2C19基因型在江苏及其周边地区汉族人群中基因多态性的分布。方法取81名汉族健康人的外周血,应用聚合酶链反应(PCR)-限制性片段长度多态性分析(RFLP)CYP2C19等位基因分型。结果在81名检测标本中,CYP2C19纯合子强代谢型、杂合子强代谢型和弱代谢型的发生率分别为38.3%、45.7%和16.0%。结论江苏及其周边地区汉族人群存在CYP2C19的基因多态性,其弱代谢型的发生率与中国汉族人总体发生率基本一致。     

Effect of genotypic differences in CYP2C19 on cure rates for Helicobacter pylori infection by triple therapy with a proton pump inhibitor, amoxicillin, and clarithromycin

BACKGROUND: Proton pump inhibitors such as omeprazole and lansoprazole are mainly metabolized by CYP2C19 in the liver. The therapeutic effects of proton pump inhibitors are assumed to depend on CYP2C19 genotype status. OBJECTIVE: We investigated whether CYP2C19 genotype status was related to eradication rates of H pylori by triple proton pump inhibitor-clarithromycin-amoxicillin (INN, amoxicilline) therapy and attempted to establish a strategy for treatment after failure to eradicate H pylori. METHODS: A total of 261 patients infected with H pylori completed initial treatment with 20 mg of omeprazole or 30 mg of lansoprazole twice a day, 200 mg of clarithromycin three times a day, and 500 mg of amoxicillin three times a day for 1 week. CYP2C19 genotypes of patients were determined with polymerase chain reaction-restriction fragment length polymorphism analysis. Patients without eradication after initial treatment were retreated with 30 mg of lansoprazole four times daily and 500 mg of amoxicillin four times daily for 2 weeks. RESULTS: Eradication rates for H pylori were 72.7% (95% confidence interval, 64.4%-81.8%), 92.1% (confidence interval, 86.4%-97.3%), and 97.8% (confidence interval, 88.5%-99.9%) in the homozygous extensive, heterozygous extensive, and poor metabolizer groups, respectively. Thirty-four of 35 patients without eradication had an extensive metabolizer genotype of CYP2C19. Nineteen of those patients were infected with clarithromycin-resistant strains of H pylori. However, there were no amoxicillin-resistant strains of H pylori. Re-treatment of H pylori infection with dual high-dose lansoprazole-amoxicillin therapy succeeded in 30 of 31 patients with extensive metabolizer genotype of CYP2C19. CONCLUSION: The majority of patients without initial eradication of H pylori had an extensive metabolizer CYP2C19 genotype but were successfully re-treated with high doses of lansoprazole and an antibiotic to which H pylori was sensitive, such as amoxicillin, even when the patients were infected with clarithromycin-resistant strains of H pylori.     

Effects of clarithromycin on the metabolism of omeprazole in relation to CYP2C19 genotype status in humans.

BACKGROUND AND PURPOSE: A triple therapy with omeprazole, amoxicillin (INN, amoxicilline), and clarithromycin is widely used for the eradication of Helicobacter pylori. Omeprazole and clarithromycin are metabolized by CYP2C19 and CYP3A4. This study aimed to elucidate whether clarithromycin affects the metabolism of omeprazole. METHODS: After administration of placebo or 400 mg clarithromycin twice a day for 3 days, 20 mg omeprazole and placebo or 400 mg clarithromycin were administered to 21 healthy volunteers. Plasma concentrations of omeprazole and clarithromycin and their metabolites were determined before and 1, 2, 3, 5, 7, 10, and 24 hours after dosing. CYP2C19 genotype status was determined by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: Subjects were classified into three groups on the basis of PCR-RFLP analyses for CYP2C19: homozygous extensive metabolizer group (n = 6), heterozygous extensive metabolizer group (n = 11), and poor metabolizer group (n = 4). Mean area under the plasma concentration-time curves from 0 to 24 hours (AUC) of omeprazole in the homozygous extensive metabolizer, heterozygous extensive metabolizer, and poor metabolizer groups were significantly increased by clarithromycin from 383.9 to 813.1, from 1001.9 to 2110.4, and from 5589.7 to 13098.6 ng x h/mL, respectively. There were significant differences in the mean AUC values of clarithromycin among the three groups. CONCLUSION: Clarithromycin inhibits the metabolism of omeprazole. Drug interaction between clarithromycin and omeprazole may underlie high eradication rates achieved by triple therapy with omeprazole, amoxicillin, and clarithromycin.     

Effect of cytochrome P4502C19 genotypic differences on cure rates for gastroesophageal reflux disease by lansoprazole

BACKGROUND AND OBJECTIVES: The acid-inhibitory effect of lansoprazole depends on differences in cytochrome P450 (CYP) 2C19 genotypes. We assessed whether therapeutic effects of lansoprazole on gastroesophageal reflux disease (GERD) depended on the CYP2C19 genotype status in relation to the grade of GERD. METHODS: A total of 65 patients with GERD (grades A-D) completed treatment with lansoprazole, by taking 30 mg orally once a day for 8 weeks. The CYP2C19 genotype status of patients was determined by polymerase chain reaction-restriction fragment length polymorphism analysis. Before and after treatment, esophageal endoscopy was performed. GERD was considered to be cured on the basis of endoscopic findings at the end of treatment. Plasma lansoprazole levels could be determined at 3 hours after the last 30-mg dose of lansoprazole in the 27 genotyped patients. RESULTS: Cure rates for GERD depended significantly on the CYP2C19 genotype status, as well as the grade of GERD before treatment. Cure rates in the homozygous extensive, heterozygous extensive, and poor metabolizer groups were 45.8%, 67.9%, and 84.6%, respectively. Cure rates in the groups with GERD grade A, grade B, and grade C or D were 85.0%, 60.0%, and 45.0%, respectively. The cure rate in patients with the homozygous extensive metabolizer genotype of CYP2C19 with a GERD grade of C or D was very low (16.7%). Plasma lansoprazole levels in patients with the homozygous extensive metabolizer genotype were the lowest of the 3 groups. CONCLUSIONS: CYP2C19 genotype status, as well as the grade of GERD before treatment, is one of the determinants for the success or failure of treatment of GERD with lansoprazole. The low cure rate in patients with the homozygous extensive metabolizer genotype appeared to be a result of these patients having the lowest plasma lansoprazole levels among the 3 genotype groups.     

Progress of tailor-made treatment of peptic ulcer]

We previously reported that a comparative pharmacokinetic study with each PPI was designed as an open, randomized, and crossover study of 18 Japanese healthy volunteers who were classified into the homozygous, heterozygous extensive metabolizer and the poor metabolizer based on the CYP2C19 genotype. With at least 1 week washout period between treatments. Plasma concentrations of PPIs and their metabolites were monitored until 12 h after medication. Pharmacokinetic profiles of omeprazole and lansoprazole were well correlated with the CYP2C19 genotype. The heterozygous extensive metabolizer was slightly different from the homozygote, but there was no statistically significant difference. The CYP2C19 genotype dependence found for lansoprazole was not obvious compared with omeprazole. As for rabeprazole, the pharmacokinetic profile was independent of the CYP2C19 genotype. CYP2C19 genotyping can provide a new strategy to choose an optimal regimen, and this genotyping is especially useful for Japanese, as the frequency of poor metabolizers is five times greater than that found among Caucasians.     

Genetic polymorphisms and the impact of a higher clopidogrel dose regimen on active metabolite exposure and antiplatelet response in healthy subjects

A double-blind crossover study was conducted in four CYP2C19 genotype-defined metabolizer groups to assess whether increase in clopidogrel dosing can overcome reduced pharmacodynamic response in CYP2C19 poor metabolizers (PMs). Ten healthy subjects in each of four metabolizer groups were randomized to a clopidogrel regimen of a 300-mg loading dose (LD) and a 75-mg/day maintenance dose (MD) for 4 days followed by 600-mg LD and 150 mg/day MD, or vice versa. The exposure levels of clopidogrel's active metabolite H4 (clopi-H4) in PMs were 71% lower on the 75-mg/day regimen and 64% lower on the 150-mg/day regimen than the corresponding exposure levels in extensive metabolizers (EMs). In PMs, the maximal platelet aggregation (MPA) induced by adenosine diphosphate (ADP) 5 μmol/l was 10.5% lower on the 75-mg/day regimen and 7.9% lower on the 150-mg/day regimen than the corresponding values in EMs. PMs who were on the clopidogrel regimen of 600-mg LD/150 mg/day MD showed clopi-H4 exposure and MPA levels similar to those in EMs who were on the regimen of 300-mg LD/75 mg/day MD. In a pooled analysis evaluating CYP1A2, CYP2B6, CYP2C9, CYP2C19, CYP3A5, CYP2D6, ABCB1, and P2RY12 polymorphisms (N = 396 healthy subjects), only CYP2C19 had a significant impact on antiplatelet response. In healthy CYP2C19 PMs, a clopidogrel regimen of 600-mg LD/150 mg/day MD largely overcomes diminished clopi-H4 exposure and antiplatelet response, as assessed by MPA levels.     

Cure of refractory duodenal ulcer and infection caused by Helicobacter pylori by high doses of omeprazole and amoxicillin in a homozygous CYP2C19 extensive metabolizer patient

A 53-year old female patient with duodenal ulcer and Helicobacter pylori infection was treated three times with a proton pump inhibitor-based triple therapy, such as lansoprazole-clarithromycin-amoxicillin (INN, amoxicilline) and lansoprazole-minocycline-cefaclor. However, the H pylori infection was not cured. A culture test revealed that her infection was a clarithromycin-resistant but amoxicillin-sensitive strain of H pylori. Moreover, a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis revealed that she was a homozygous extensive metabolizer of cytochrome P450 (CYP) 2C19 (wt/wt). The usual dose of the proton pump inhibitor was therefore assumed to be insufficient for her and then she was treated with a high dose of omeprazole (120 mg/day) and amoxicillin (2,250 mg/day) for 2 weeks. The H pylori infection and the ulcer lesion were then cured. One of the factors associated with success or failure of cure of H pylori infection by the proton pump inhibitor-based triple therapy appeared to be CYP2C19 genotype status. Dual treatment with a sufficient dose of a proton pump inhibitor plus amoxicillin could cure H pylori infection even after the failure to cure H pylori infection by a usual proton pump inhibitor-based triple therapy in patients with the wt/wt homozygous extensive metabolizer genotype of CYP2C19.