【病例学习第33期】Test Your Skills

From Pharmacy Times
Thanks to the author Craig I. Coleman, PharmD(Dr. Coleman is an assistant professor of pharmacy practice and director of the pharmacoeconomics and outcomes studies group at the University of Connecticut School of Pharmacy.)

以下为正文(需要翻译的部分),欢迎会员认领并尽可能在48小时内翻译完毕并提交,将奖励50威望和50金钱.

HC is a 57-year-old man who comes to the pharmacy counter to pick up his refill for clopidogrel 75 mg. When he goes to pay for his prescription, he hands the pharmacist a box of Prilosec OTC (omeprazole) and explains that he has recently been experiencing mild episodes of heartburn. HC wants to know if Prilosec OTC would work for him.

How should the pharmacist respond?

ANSWER
Although omeprazole (Prilosec OTC) is certainly an effective therapy for the self-management of occasional heartburn, it is a poor choice for HC. This is because patients at risk for heart attacks or strokes who use clopidogrel to prevent blood clots do not get the full effect of the drug when taken with cytochrome P450 2C19 (CYP2C19) isoenzyme inhibitors. Omeprazole is one of a number of drugs that inhibits the CYP2C19 isoenzyme responsible for the conversion of clopidogrel into its active metabolite. These effects are seen regardless of whether the 2 drugs are given at the same time or taken at different times during the day. As a result, studies have shown that when clopidogrel and omeprazole are taken together, the effectiveness of clopidogrel is reduced. The pharmacist should counsel HC about this drug interaction and recommend he try an OTC H2 blocker instead. Specifically, ranitidine, famotidine, or nizatidine are reasonable choices, whereas cimetidine, also a CYP2C19 inhibitor, is not. Although lansoprazole is also available over-thecounter, limited information exists about drug interactions between clopidogrel and proton pump inhibitors other than omeprazole and esomeprazole, making the recommendation to try lansoprazole more difficult.

我来试试吧。有不地道的地方请多多指教。

57岁的HC到药房续取他用的75mg的氯吡格雷，将处方付给药师的同时拿出一盒奥美拉唑（OTC），告诉药师最近他有轻微胃痛的症状，他想知道奥美拉唑是否对此有作用。
回答：
尽管奥美拉唑对可自我管理的偶发的胃痛有明确的疗效，但HC不合适用。这是因为服用氯吡格雷用以防凝的患者在同服细胞色素P450 2C19同工酶抑制剂时作用得不到充分发挥以至会出现心脏病或者中风发作的风险。奥美拉唑可抑制CYP2C19同工酶将氯吡格雷转换为有活性的代谢产物。无论这两种药同时服还是同一天服都会出现这一结果。因此，研究显示
氯吡格雷与奥美拉唑同服，会减弱氯吡格雷的作用。药师应忠告HC关注氯吡格雷与奥美拉唑的相互作用，建议他可使用H2受体阻滞剂替代奥美拉唑，如雷尼替丁、法莫替丁、尼扎替丁都是合理的选择，而西咪替丁不可以选，因它也是CYP2C19抑制剂。尽管兰索拉唑也是OTC，但建议使用它则更困难，因为氯吡格雷与质子泵抑制剂之间的药物相互作用除了奥美拉唑、埃索美拉唑以外的其它质子泵抑制剂的信息有限。