Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
Clin Drug Investig. 2012 Feb 1;32(2):131-7. doi: 10.2165/11595860-000000000-00000.
Warfarin is a commonly used oral anticoagulant and its interaction with other drugs can result in serious thrombotic or bleeding events. Currently, there is no definitive evidence on the possibility of an interaction between warfarin and oseltamivir.
The objective of this study was to investigate whether a possible drug interaction between oseltamivir and warfarin exists.
A retrospective review of patients on anticoagulation therapy who took oseltamivir from 1 September 2009 to 28 February 2010 at Seoul National University Hospital, Seoul, Korea, was carried out.
Among 15 patients who were tested for prothrombin time/international normalized ratio (PT/INR) [hereafter referred to as INR] within 10 days of starting oseltamivir therapy and had previously stable INR values, seven patients had an increase in INR levels after oseltamivir administration, and the other eight patients maintained stable INR levels. The mean ± SD INR value was 2.08 ± 0.46 prior to the administration of oseltamivir and 5.15 ± 2.00 after treatment with oseltamivir (measured a mean ± SD 5.7 ± 2.5 days after the first dose of oseltamivir) in the INR-increased group and, respectively, 2.03 ± 0.40 and 1.97 ± 0.54 (measured 6.4 ± 2.5 days after the first dose of oseltamivir) in the INR-unaffected group. The dosage and duration of oseltamivir treatment were similar whether the INR values increased or not. There were bleeding events such as blood-tinged sputum and bloody ascites in three patients in the INR-increased group. The INR level recovered within 5 days after discontinuation of warfarin in these three patients. The positivity rates for influenza A H1N1 were not different between the INR-increased group and the INR-unaffected group.
This case series suggests the possibility of a potential interaction between warfarin and oseltamivir. Further well designed prospective studies and genetic evaluations are needed to determine the exact nature of the interaction between warfarin and oseltamivir.
华法林是一种常用的口服抗凝剂，其与其他药物的相互作用可能导致严重的血栓或出血事件。目前，尚无关于奥司他韦与华法林之间可能发生相互作用的确切证据。
本研究旨在探讨奥司他韦与华法林之间是否存在潜在的药物相互作用。
对 2009 年 9 月 1 日至 2010 年 2 月 28 日在韩国首尔国立大学医院接受抗凝治疗并服用奥司他韦的患者进行了回顾性研究。
在 15 例于开始奥司他韦治疗后 10 天内检测凝血酶原时间/国际标准化比值（PT/INR）[以下简称 INR]并具有先前稳定 INR 值的患者中，7 例患者在服用奥司他韦后 INR 水平升高，另 8 例患者 INR 水平保持稳定。INR 升高组患者在服用奥司他韦前的平均 INR 值为 2.08±0.46，在服用奥司他韦后为 5.15±2.00（在服用奥司他韦首剂后平均 5.7±2.5 天测量），而 INR 未受影响组患者在服用奥司他韦前的平均 INR 值为 2.03±0.40，在服用奥司他韦后为 1.97±0.54（在服用奥司他韦首剂后平均 6.4±2.5 天测量）。INR 值升高组和 INR 未受影响组患者的奥司他韦治疗剂量和持续时间相似。在 INR 升高组的 3 例患者中出现了痰中带血和血性腹水等出血事件。这 3 例患者在停用华法林后 INR 值在 5 天内恢复正常。INR 升高组和 INR 未受影响组的甲型 H1N1 流感阳性率无差异。
本病例系列提示华法林与奥司他韦之间可能存在潜在的相互作用。需要进一步设计良好的前瞻性研究和遗传评估来确定华法林与奥司他韦之间相互作用的确切性质。
