Takeuchi Masato, Nakano Sayuri, Tanaka-Mizuno Sachiko, Nishiyama Chika, Doi Yuko, Arai Masaru, Fujii Yosuke, Matsunaga Toshiyuki, Kawakami Koji
Department of Pharmacoepidemiology, Graduate School of Medicine and Public Health, Kyoto University.
Department of Medical Statistics, Shiga University of Medical Science.
Biol Pharm Bull. 2019;42(3):389-393. doi: 10.1248/bpb.b18-00576.
Warfarin is a drug used for anticoagulation management, with a narrow therapeutic range and multiple drug-drug interactions. Adherence and proper use of concomitant medication are thus fundamental to the efficacy and safety of warfarin therapy. In 2012, we retrospectively analyzed data from three large-scale pharmacy chains in Japan. We included all adults (≥ 20 years old) with at least one record of warfarin dispensation. We examined patient demographic data, adherence as measured by medication possession ratio (MPR), and co-dispensation focusing on the number of concomitant dispensations and concurrent use of medications that increase bleeding risk. Thresholds of underadherence and overadherence were set at <0.9 and >1.1, considering the narrow therapeutic window. We reviewed 443007 warfarin dispensation records of 71340 individuals (median age, 73 years; 62% male). The MPR was 1.0 (interquartile range: 0.96-1.0), and underadherence and overadherence was found in 16.3 and 1.9% of individuals, respectively. The median number of co-dispensed drugs was eight at each pharmacy encounter, which did not differ by age group. Drugs associated with a high bleeding risk were dispensed in 40.0% of encounters and accounted for 16.4% of all co-dispensed drugs. In summary, we found optimal overall adherence, as assessed by MPR, among our Japanese study population, even when defining a strict cut-off value. However, polypharmacy was common in all age groups and medications with a high bleeding risk profile were often co-dispensed with warfarin. Future research addressing how these dispensation patterns affect patient outcome is warranted.
华法林是一种用于抗凝管理的药物，治疗范围狭窄且存在多种药物相互作用。因此，坚持服药并正确使用伴随药物对于华法林治疗的疗效和安全性至关重要。2012年，我们回顾性分析了日本三家大型连锁药店的数据。我们纳入了所有至少有一次华法林配药记录的成年人（≥20岁）。我们检查了患者的人口统计学数据、用药持有率（MPR）衡量的依从性，以及关注伴随配药数量和增加出血风险药物的同时使用情况的联合配药情况。考虑到治疗窗狭窄，将依从性不足和过度依从的阈值设定为<0.9和>1.1。我们回顾了71340名个体（中位年龄73岁；62%为男性）的443007条华法林配药记录。MPR为1.0（四分位间距：0.96 - 1.0），分别有16.3%和1.9%的个体存在依从性不足和过度依从情况。每次药店配药时联合配药的药物中位数为8种，各年龄组之间无差异。40.0%的配药中开具了与高出血风险相关的药物，占所有联合配药药物的16.4%。总之，即使定义了严格的临界值，我们在日本研究人群中通过MPR评估发现总体依从性最佳。然而，多药联用在所有年龄组中都很常见，且具有高出血风险特征的药物经常与华法林联合配药。有必要开展进一步研究，探讨这些配药模式如何影响患者预后。
