Drug Interaction Report

MONITOR: Coadministration with drugs that are subject to substantial renal clearance such as trimethoprim/sulfamethoxazole and nonsteroidal anti-inflammatory drugs (NSAIDs) may result in delayed clearance of pralatrexate. The mechanism is competitive inhibition of renal excretion, as approximately 34% of pralatrexate is eliminated unchanged by the kidney.

MANAGEMENT: Caution is advised if pralatrexate is prescribed in combination with trimethoprim/sulfamethoxazole or NSAIDs. Complete blood cell counts as well as renal and hepatic function should be closely monitored. Treatment interruption or dose reduction of pralatrexate may be required if toxicities such as mucositis, myelosuppression, or liver enzyme abnormalities develop. Patients should be advised to contact their physician if they develop oral ulcers, painful swallowing, vomiting, diarrhea, and/or signs and symptoms of myelosuppression such as pallor, dizziness, fatigue, lethargy, fainting, easy bruising or bleeding, or signs of infection such as fever, chills, sore throat, body aches, and other influenza-like symptoms.

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.