Drug Interaction Report

GENERALLY AVOID: Coadministration with rolapitant may increase the plasma concentrations of drugs that are substrates of the P-glycoprotein (P-gp) efflux transporter. When a 0.5 mg dose of digoxin, a P-gp probe substrate, was administered with a 180 mg dose of rolapitant, digoxin peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 70% and 30%, respectively.

MANAGEMENT: Concomitant use of rolapitant with drugs that are P-gp substrates should generally be avoided. If concomitant administration is unavoidable, caution is advised, particularly with drugs that have a narrow therapeutic range. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate for some drugs whenever rolapitant is added to or withdrawn from therapy.

ADJUST DOSING INTERVAL: Food may reduce the oral bioavailability of silodosin. The effect of a moderate-fat, moderate-calorie meal on silodosin pharmacokinetics was variable and decreased silodosin maximum plasma concentration (Cmax) by approximately 18% to 43% and systemic exposure (AUC) by 4% to 49% across three different studies. The maximum effect of food (i.e., coadministration with a high-fat, high-calorie meal) on the pharmacokinetics of silodosin was not evaluated. Safety and efficacy clinical trials for silodosin were always conducted in the presence of food intake.

MANAGEMENT: Patients should be instructed to take silodosin with a meal to reduce the risk of adverse events.