Hemorrhage during warfarin therapy associated with cotrimoxazole and other urinary tract anti-infective agents: a population-based study

• Published in: Archives of internal medicine (1960) Vol. 170; no. 7; p. 617
• Main Authors: Fischer, Hadas D, Juurlink, David N, Mamdani, Muhammad M, Kopp, Alexander, Laupacis, Andreas
• Format: Journal Article
• Language: English
• Published: United States 12.04.2010
• Subjects: Aged; Aged, 80 and over; Amoxicillin - adverse effects; Ampicillin - adverse effects; Anti-Infective Agents, Urinary - adverse effects; Anticoagulants - adverse effects; Case-Control Studies; Databases, Factual; Drug Interactions; Drug Therapy, Combination; Female; Gastrointestinal Hemorrhage - chemically induced; Humans; Male; Multivariate Analysis; Odds Ratio; Ontario; Trimethoprim, Sulfamethoxazole Drug Combination - adverse effects; Urinary Tract Infections - drug therapy; Warfarin - adverse effects; Ontario

Some antibiotic agents, including cotrimoxazole, inhibit the metabolism of warfarin sodium and possibly increase the risk of hemorrhage. We examined the risk of upper gastrointestinal (UGI) tract hemorrhage in older patients receiving warfarin in combination with antibiotics commonly used to treat u...