Drug interactions and risk of acute bleeding leading to hospitalisation or death in patients with chronic atrial fibrillation treated with warfarin

• Verfasst von: Gasse, Christiane [VerfasserIn]
• Verfasst von: Hollowell, Jennifer [VerfasserIn]
• Verfasst von: Meier, Christoph [VerfasserIn]
• Verfasst von: Haefeli, Walter E. [VerfasserIn]
• Titel: Drug interactions and risk of acute bleeding leading to hospitalisation or death in patients with chronic atrial fibrillation treated with warfarin
• Verf.angabe: Christiane Gasse, Jennifer Hollowell, Christoph R. Meier, Walter E. Haefeli
• Jahr: 2005
• Umfang: 7 S.
• Teil: volume:94
• Teil: year:2005
• Teil: number:9
• Teil: pages:537-543
• Teil: extent:7
• Fussnoten: Online: 07. Dezember 2017 ; Gesehen am 18.05.2021
• Titel Quelle: Enthalten in: Thrombosis and haemostasis
• Ort Quelle: Stuttgart : Thieme, 1976
• Jahr Quelle: 2005
• Band/Heft Quelle: 94(2005), 9, Seite 537-543
• ISSN Quelle: 2567-689X
• DOI: doi:10.1160/TH05-03-0166
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1758039647

Abstract

<p>Although drug interactions with warfarin are an important cause of excessive anticoagulation, their impact on the risk of serious bleeding is unknown. We therefore performed a cohort study and a nested case-control analysis to determine the risk of serious bleeding in 4152 patients (aged 40-84 years) with nonvalvular atrial fibrillation (AF) taking long-term warfarin (>3 months). The study population was drawn from the UK General Practice Research Database. More than half (58%) of eligible patients used potentially interacting drugs during continuous warfarin treatment. Among 45 identified cases of incident idiopathic bleeds (resulting in hospitalisation within 30 days or death within 7 days) and 143 matched controls, more cases than controls took ≥1 potentially interacting drug within the preceding 30 days (62.2% vs. 35.7%) and used >4 drugs (polypharmacy) within the preceding 90 days (80.0% vs. 66.4%). Conditional logistic regression analysis yielded an odds ratio (OR) of 3.4 (95% confidence interval [CI]: 1.4-8.5) for the risk of serious bleeding in patients treated with warfarin and ≥1 drugs potentially increasing the effect of warfarin vs. warfarin alone adjusted for polypharmacy, diabetes, hypertension, heart failure, and thyroid disease; the adjusted OR for the combined use of warfarin and aspirin vs. warfarin alone was 4.5 (95% CI: 1.1-18.1). We conclude that concurrent use of potentially interacting drugs with warfarin is associated with a 3 to 4.5-fold increased risk of serious bleeding in long-term warfarin users.</p>