Karolinska Institutet, Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska University Hospital Huddinge, Stockholm, Sweden.
Department of Clinical Science and Education at Södersjukhuset, Karolinska Institutet, Stockholm, Sweden.
Eur J Clin Pharmacol. 2019 Oct;75(10):1387-1392. doi: 10.1007/s00228-019-02703-3. Epub 2019 Jun 14.
Some data indicate that simvastatin may increase the anticoagulative effect in patients treated with warfarin, but the evidence is scarce. The aim of the present study was to investigate how the anticoagulative effect of warfarin is affected by the initiation of simvastatin in a very large patient sample.
In a retrospective cohort study, we included 5637 individuals on warfarin treatment initiating simvastatin. INR values and warfarin doses were calculated week-by-week during co-treatment. Data were obtained from two large Swedish warfarin registers and from the Swedish Prescribed Drug Register.
INR increased from 2.43 at baseline to 2.58, 4 weeks after simvastatin initiation, and did not stabilize until the last quarter of the year studied. Consequently, the proportion of patients with an INR above 3 increased from around 8 to 15%.
In conclusion, initiation of simvastatin resulted in moderately increased INR values and subsequent dose decreases in patients already on warfarin. In order to avoid the increased risk of bleeding, the initiation of simvastatin may be accompanied by closer INR monitoring.
一些数据表明，辛伐他汀可能会增加华法林治疗患者的抗凝效果，但证据有限。本研究旨在调查在一个非常大的患者样本中，辛伐他汀的起始如何影响华法林的抗凝效果。
在一项回顾性队列研究中，我们纳入了 5637 名正在接受华法林治疗并开始使用辛伐他汀的患者。在联合治疗期间，每周计算一次 INR 值和华法林剂量。数据来自两个大型的瑞典华法林登记处和瑞典处方药物登记处。
INR 从基线时的 2.43 升高至辛伐他汀起始后 4 周的 2.58，直到研究年度的最后一个季度才稳定下来。因此，INR 高于 3 的患者比例从约 8%增加到 15%。
总之，辛伐他汀的起始导致已经接受华法林治疗的患者 INR 值适度升高，随后剂量减少。为了避免出血风险增加，辛伐他汀的起始可能需要更密切的 INR 监测。
