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 juice may significantly increase the systemic exposure to eliglustat. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. Because eliglustat is predicted to cause prolongation of the PR, QTc, and QRS cardiac intervals at substantially elevated plasma concentrations, consumption of grapefruit juice during treatment may increase the risk of bradycardia, atrioventricular block, cardiac arrest, and serious ventricular arrhythmias such as torsade de pointes.

MANAGEMENT: Patients treated with eliglustat should avoid consumption of grapefruit and grapefruit juice.