Effects of <Emphasis Type="Italic">CYP3A5, MDR1</Emphasis> and <Emphasis Type="Italic">CACNA1C</Emphasis> polymorphisms on the oral disposition and response of nimodipine in a Chinese cohort

Purpose  Our objective was to study the effects of polymorphic the CYP3A5 (allele *1 and *3), MDR1 [single nucleotide polymorphisms (SNPs) G2677T, C3435T] and CACNA1C (SNPs rs2239128, rs2239050, rs2238032) genes on nimodipine oral disposition and response in healthy Chinese subjects. Methods  Pharmacokinetics and pharmacodynamics data were obtained from a bioequivalence study, and the same 20 subjects were genotyped for CYP3A, MDR1 and CACNA1C. An additional 41 healthy Chinese subjects were recruited to obtain an indication of the distribution of CACNA1C polymorphisms in the Chinese population. Racial differences in the frequency of CACNA1C alleles were assessed. The phenotype differences between genotypes were analyzed. Results  The allelic frequencies of rs2239050 and rs2238032 in our Chinese cohort were different from those in a Caucasian population (p < 0.01). Subjects with mutant alleles (*3/*3) of the CYP3A5 gene had a decreased oral clearance of nimodipine, with a higher lnC_max or compared with those subjects with the heterozygote (*1/*3) or wild type (*1/*1) gene. The CACNA1C rs2239128 C and rs2239050 G SNPs were associated with a stronger efficacy compared with their respective alleles, rs2239128 T and rs2239050 C. MDR1 polymorphisms showed no significance in terms of nimodipine disposition. Conclusions  The polymorphic CYP3A5 (allele *1 and *3) and CACNA1C genes have effects on nimodipine oral disposition and response in healthy Chinese subjects. The homozygous variant of CYP3A5 (*3/*3) was associated with significantly increased nimodipine exposure. CACNA1C SNPs rs2239128 C and rs2239050 G were associated with a stronger efficacy.     

Exploring emerging technologies using metaphors--a study of orphan drugs and pharmacogenomics

Due to uncertainties of several aspects of emerging health technologies, there is a need to anticipate these developments early. A first step would be to gather information and develop future visions about the technology. This paper introduces metaphor analysis as a novel way to do this. Specifically, we study the future of pharmacogenomics by comparing this technology with orphan drugs, which are more established and often act as a model with comparable (economic, research organisation, etc.) characteristics. The analysis consists of describing the dominant metaphors used and structurally exploring (dis)similarities between pharmacogenomics and orphan drugs developments. This comparison leads to lessons that can be learnt for the emerging pharmacogenomics future. We carried out a comprehensive literature review, extracting metaphors in a structured way from different areas of the drug research and development pipeline. The paper argues that (1) there are many similarities between orphan drugs and pharmacogenomics, especially in terms of registration, and social and economic impacts; (2) pharmacogenomics developments are regarded both as a future 'poison' and a 'chance', whereas orphan drugs are seen as a 'gift', and at the same time as a large 'problem'; and (3) metaphor analysis proves to be a tool for creating prospective images of pharmacogenomics and other emerging technologies.     

药物基因组学临床部署现状及在中国的机遇与挑战

药物基因组学（pharmacogenomics,PGx）作为精准医学临床部署的首选领域,具有广阔的发展前景。目前国外已将抗肿瘤、慢病管理、华法林抗凝等领域的PGx数据部署到电子病历系统中,以辅助临床决策。而我国因电子病历系统升级改造复杂,基因检测技术不高、费用高昂,PGx知识库缺乏等多方面复杂因素制约,PGx的临床部署仍存在巨大挑战。作者旨在借鉴PGx临床部署在国外取得的成绩,分析其在我国临床部署中面临的机遇和挑战,以推进我国PGx临床部署的顺利开展和实施,贯彻落实其在临床辅助决策系统中的应用。     

阿片类药物所致呼吸抑制与基因多态性

阿片类药物目前在临床上应用广泛,中度至重度疼痛以及大多数术后疼痛的治疗多依赖于阿片类药物的使用。目前临床上常用的吗啡等阿片类镇痛药治疗指数范围窄,个体差异较大,而且常常伴随着严重的耐受性和成瘾性,甚至呼吸抑制(RD)等严重不良反应。研究阿片受体的基因多态性有助于从分子生物学的角度解释个体间对阿片类药物反应存在的差异。确定基因特异性有助于指导临床用药,降低其呼吸抑制等不良反应的发生率。     

药物基因组学在药动学研究中的应用

药物基因组学是一门充满活力并迅速发展的新兴学科,以探讨药物作用的遗传分布,确定药物作用靶点,提高药物效应及安全性为目标,研究影响药物分布、消除等个体差异的基因特性,以及基因变异所致的不同病人对药物的不同反应等.本文综述了药物基因组学在药动学研究中的进展情况,介绍和论述了药物基因组学的概念和研究内容;探讨了药物基因组学在药动学中的应用,药物代谢酶的多态性和药物转运体的多态性;并展望药物基因组学的应用前景.     

Genetics of migraine and pharmacogenomics: some considerations

Migraine is a complex disorder caused by a combination of genetic and environmental factors. Although family and twin studies show that there is a genetic component in migraine, no genes predisposing to common forms of the disorder, migraine with and without aura, have been identified. Patients with migraine respond differently to a given drug administered. The efficacy of therapy and the occurrence of adverse drug response are a consequence of individual variability. Genetic profiling of predisposition to migraine should facilitate the development of more effective diagnostic and therapeutic applications. The development of International Hap Map project could provide a powerful tool for identification of the candidate genes in this complex disease and pharmacogenomics research could be the promise for individualized treatments and prevention of adverse drug response. This is a “Springer Open Choice” article. Unrestricted non-commercial use, distribution, and reproduction in any medium is permitted, provided the original author and source are credited.     

Cancer pharmacogenomics: SNPs, chips, and the individual patient

There is great heterogeneity in a patient's response to medications, often requiring empirical strategies to define the appropriate drug therapy for each patient. Pharmacogenomics aims to elucidate further the inherited nature of interindividual differences in drug disposition and effects, with the ultimate goal of providing a stronger scientific basis for selecting the optimal drug therapy and dosage for each patient. These genetic insights should also lead to mechanism-based approaches to the discovery and development of new medications. Genetic polymorphisms in drug metabolizing enzymes, transporters, receptors, and other drug targets have been linked to interindividual differences in the efficacy and toxicity of many medications. For example, polymorphism in thiopurine methyltransferase (TPMT) results in altered degradation of the commonly prescribed agent 6-mercaptopurine This genetic variant has significant clinical implications because patients with functionally relevant homozygous mutations in the TPMT gene experience extreme or fatal toxicity after administration of normal doses of 6-MP. In addition, patients heterozygous for mutations in TPMT require slight dosage reduction of 6-MP and experience a greater degree of systemic toxicity from the agent. This and other examples of genetic polymorphism relevant to the treatment of cancer are highlighted to illustrate the promise and pitfalls of the exciting area of cancer therapeutics, with the potential of providing a stronger scientific basis to optimize drug therapy on the basis of each patient's genetic constitution.     

人类白细胞抗原基因多态性与药物不良反应研究进展

药物不良反应已成为危害人类健康的重要公共卫生问题.人类白细胞抗原基因(HLA)是目前已知的人类最复杂基因系统.近年来研究发现,人类白细胞抗原基因多态性与药物不良反应之间有着很强的遗传相关性,且部分研究成果在临床已得到很好地应用.本文就人类白细胞抗原基因多态性与药物不良反应之间的研究及其临床应用进行阐述.