Drug Interaction Report

MONITOR: Coadministration with ruxolitinib may increase the plasma concentrations of drugs that are substrates of the P-glycoprotein efflux transporter and/or the breast cancer resistance protein (BRCP) in the intestine. The mechanism is decreased clearance via these routes due to inhibition by ruxolitinib. The clinical significance is unknown.

MANAGEMENT: Caution is advised if ruxolitinib must be used concurrently with medications that are substrates of the P-glycoprotein efflux transporter and/or the breast cancer resistance protein (BRCP) , particularly those with a narrow therapeutic range. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate for some drugs whenever ruxolitinib is added to or withdrawn from therapy. The interaction may possibly be avoided or minimized if the doses of the affected medications are separated for as long as possible.

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of ruxolitinib. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits.

MANAGEMENT: Patients treated with ruxolitinib should avoid consumption of grapefruit, grapefruit juice, and any supplement containing grapefruit extract. Ruxolitinib may be administered with or without food.