We experienced a serious interaction between miconazole gel and warfarin. The patient had just undergone an aortic and mitral value replacement and thus was medicated with warfarin at a dosage according to the International Normalized Ratio (INR) of about 2.0-2.5. He was prescribed miconazole gel 400 mg/day for thrush induced by steroid for asthma. About two weeks later, he showed bleeding in the mouth and underwent a medical examination. His INR was higher than the upper of measurement limit and so he was immediately hospitalized. Vitamin K was given, miconazole gel and warfarin ware stopped. Two weeks later, his INR was less than 3.0 and thus the warfarin was restarted. But his warfarin dose was less than one third of dosethat had been given before hospitalization.
The interaction between miconazole gel and warfarin that we experienced by our patient while was as serious as the reports from abroad.
