Drug Interaction Report

Coadministration of niraparib with a P-glycoprotein (P-gp) and/or Breast Cancer Resistance Protein (BCRP) inhibitor may increase the plasma concentration of niraparib, which is a substrate of these efflux transporters. However, due to the high permeability and bioavailability of niraparib, the risk of a clinically relevant interaction with inhibitors of these transporters is unlikely. No dose adjustment is recommended if a P-gp and/or BCRP inhibitor is added to treatment with niraparib.

GENERALLY AVOID: Grapefruit and grapefruit juice may significantly increase the plasma concentrations of orally administered ranolazine. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. Because ranolazine prolongs QT interval in a dose-dependent manner, high plasma levels of ranolazine may increase the risk of ventricular arrhythmias such as ventricular tachycardia, ventricular fibrillation, and torsade de pointes.

MANAGEMENT: Patients treated with ranolazine should avoid consumption of grapefruit juice and other grapefruit products if possible. Otherwise, the dosage of ranolazine should be limited to 500 mg twice a day.