Drug Interaction Report

MONITOR: Coadministration with elagolix may increase the plasma concentrations of drugs that are substrates of the P-glycoprotein (P-gp) transporter. The proposed mechanism is decreased clearance in the intestine, kidney, and/or liver due to inhibition of P-gp-mediated efflux by elagolix. When a single 0.5 mg dose of the probe P-gp substrate digoxin was coadministered with elagolix (200 mg twice daily for 10 days) in 11 study subjects, digoxin peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 71% and 26%, respectively, compared digoxin administered alone.

MANAGEMENT: Caution is advised when elagolix is used concurrently with drugs that are P-gp substrates, particularly those with a narrow therapeutic range. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate for some drugs whenever elagolix is added to or withdrawn from therapy.