Drug Interaction Report

ADJUST DOSING INTERVAL: In a clinical trial, administration of palifermin within 24 hours of chemotherapy resulted in increased severity and duration of oral mucositis, presumably due to increased sensitivity of the rapidly dividing epithelial cells in the immediate post-chemotherapy period.

MANAGEMENT: Palifermin should not be administered within 24 hours before, during infusion of, or within 24 hours after administration of myelotoxic chemotherapy.

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of pazopanib. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. Although not studied, the interaction may increase the risk of QT interval prolongation and torsade de pointes arrhythmia as well as severe and fatal hepatotoxicity associated with the use of pazopanib.

ADJUST DOSING INTERVAL: Food increases the oral bioavailability of pazopanib. The mechanism of interaction is unknown. Administration of pazopanib with a high-fat or low-fat meal results in an approximately 2-fold increase in peak plasma concentration (Cmax) and systemic exposure (AUC).

MANAGEMENT: Patients treated with pazopanib should avoid consumption of grapefruit, grapefruit juice, and any supplement containing grapefruit extract. Pazopanib should be administered at least one hour before or two hours after a meal.