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.

ADJUST DOSE: In-vivo studies have demonstrated that the absorption of bromfenac is greatly reduced if the drug is taken within three and one-half hours following a high fat meal. The concomitant administration of a high fat meal has led to a 75% reduction in peak plasma concentrations and a 60% reduction in total area under the curve. The mechanism has not been described.

MANAGEMENT: An increased dosage of bromfenac (from 25 to 50 mg) may be needed if a high fat meal is consumed. The clinician may want to warn the patient about subtherapeutic analgesic effects if high fat meals are regularly consumed.