Fluconazole can increase the anticoagulant effect of warfarin, prolong prothrombin time, and contribute to bruising, epistaxis, gastrointestinal bleeding, hematuria, or melena. Careful INR and bleeding monitoring is required, and the prescriber can adjust warfarin if needed. The nurse should not independently stop or replace anticoagulant therapy, and fluconazole does not predictably lower INR.
In-depth explanation
Clinical reasoning
Fluconazole inhibits pathways involved in warfarin metabolism, increasing exposure and bleeding risk. The interaction develops over time and requires laboratory plus clinical surveillance.
Decision rule
Coordinate closer INR and bleeding assessment whenever fluconazole is added to warfarin; leave dose adjustment to the prescriber-directed plan.
For study reference only. Always follow current clinical guidelines and your institution’s protocols.