Drug Interaction Report

MONITOR: The use of pentoxifylline has been associated with bleeding and/or prolongation in prothrombin time. Theoretically, the risk of bleeding may be increased by concomitant treatment with anticoagulants or other agents that affect hemostasis such as nonsteroidal anti-inflammatory drugs (NSAIDs), platelet inhibitors, thrombin inhibitors, thrombolytic agents, and dextran. There have been postmarketing reports of increased anticoagulant activity in patients receiving vitamin K antagonists in combination with pentoxifylline.

MANAGEMENT: Caution is advised if pentoxifylline is administered with anticoagulants or other agents that affect hemostasis. Patients on vitamin K antagonists such as warfarin should have more frequent monitoring of INR following initiation or dosage change of pentoxifylline, while patients receiving other agents that affect hemostasis should have periodic examinations for bleeding including hematocrit and/or hemoglobin.