Drugs Which May Potentiate Anticoagulant Effect and Increase PT/INR

Major Effect	Moderate Effect	Minor Effect
Amiodarone Anabolic steroids Cimetidine Clarithromycin Clofibrate Co-trimoxazole Disulfiram Erythromycin Fluconazole Metronidazole Miconazole Phenylbutazone Sulfinpyrazone Sulfonamides	Acetaminophen (>1.3g/day) Cisapride Fluoroquinalones (e.g. Cipro) Fluxetine/Fluvoxamine Fluorouracil Isoniazid Itraconazole Omeprazole Propafenone Propoxyphene Quinidine Tamoxifen Tetracycline Thyroid hormones	Acabose Allopurinol Chloral hydrate Disopyramide Ifosfamide HMG-CoA reductase inhibitors Metolazone Moricizine Nalidixic acid Propranolol Theophylline Tricyclic antidepressants