A 61-year-old man with a medical history of gastroesophageal reflux disease presented with complaints of gross hematuria for 2 days and occasional epistaxis for 1 week. The medication list included only ranitidine. Laboratory data showed significantly elevated prothrombin time and international normalized ratio. The liver panel was normal. On inspection, the patient's bottle of ranitidine, which was refilled 20 days before, contained 5-mg tablets of warfarin. The international normalized ratio and prothrombin time were reversed with FFP, vitamin K, and Novoseven.