Friday, April 24, 2009
Zitromax anticoagulans warfarin
Azithromycin (Zithromax) May Potentiate the Effects of Oral Anticoagulants
On March 6, the FDA approved safety labeling revisions for azithromycin tablets and injection (Zithromax; Pfizer, Inc) to warn of a drug interaction with warfarin.
Although a study of 22 healthy men demonstrated that a 5-day course of azithromycin had no effect on prothrombin time from a subsequently administered dose of warfarin, spontaneous postmarketing reports suggest that concomitant administration of azithromycin may potentiate the effects of oral anticoagulants. The FDA advises that prothrombin times be carefully monitored in patients receiving azithromycin with oral anticoagulants.
Azithromycin is a macrolide antibiotic indicated for the treatment of mild to moderate infections caused by susceptible strains of designated microorganisms. Specific indications include nongonococcal urethritis and cervicitis from Chlamydia trachomatis and the prophylaxis and treatment of disseminated mycobacterium avium complex disease.
Warfarin is an anticoagulant indicated for the prophylaxis and/or treatment of venous thrombosis, pulmonary embolism, and thromboembolic complications associated with atrial fibrillation and/or cardiac valve replacement. It is also indicated to reduce the risk for death, recurrent myocardial infarction, and thromboembolic events after myocardial infarction.
