Hyperprothrombinemia as a result of a possible warfarin and intravaginal miconazole interaction.
Warfarin, a commonly prescribed anticoagulant, has many potential drug interactions. We describe a case of intravaginal miconazole potentiating the effects of warfarin in a patient previously stable on a consistent dose of 8.5 mg warfarin daily. Following a course of intravaginal miconazole and a dosage increase to 9 mg daily, her international normalized ratio (INR) increased from 2.0 to 5. After the course of miconazole was complete, the patient was stable with a therapeutic INR (mean INR 2.9) on 9 mg warfarin daily. Clinicians should consider the possibility of systemic absorption of intravaginal miconazole, and a resultant increase in warfarin's anticoagulant effect.
Thomas
Jeremy L
JL
Department of Pharmacy Practice, University of Arkansas for Medical Sciences, Little Rock, AR, USA. jlthomas2@uams.edu
Dunn
Donald
D
Pelletier
Allen
A
Franks
Andrea S
AS
D000282:Administration, Intravaginal; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects*; D000935:Antifungal Agents / Q000008:administration & dosage / Q000009:adverse effects*; D001777:Blood Coagulation / Q000187:drug effects; D001778:Blood Coagulation Disorders / Q000139:chemically induced*; D004347:Drug Interactions; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D008825:Miconazole / Q000008:administration & dosage / Q000009:adverse effects*; D008875:Middle Aged; D011517:Prothrombin Time; D014859:Warfarin / Q000009:adverse effects*
D000925:Anticoagulants; D000935:Antifungal Agents; D014859:Warfarin; D008825:Miconazole