Drug Interaction Report

MONITOR: Coadministration with potent inhibitors of CYP450 3A4 that can also inhibit P-glycoprotein (P-gp) may significantly increase the plasma concentrations of darolutamide, which is a substrate of both the isoenzyme and the efflux transporter. When darolutamide was coadministered with itraconazole, a dual P-gp and potent CYP450 3A4 inhibitor, mean darolutamide peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 40% and 70%, respectively, compared to administration of darolutamide alone.

MANAGEMENT: Caution is advised when darolutamide is used with dual P-gp and potent CYP450 3A4 inhibitors. Patients should be monitored more frequently for adverse effects such as fatigue, hypertension, neutropenia and abnormal liver function tests, and the darolutamide dosage adjusted as necessary in accordance with the product labeling.

MONITOR: Coadministration with potent inhibitors of CYP450 3A4 that can also inhibit P-glycoprotein (P-gp) may significantly increase the plasma concentrations of darolutamide, which is a substrate of both the isoenzyme and the efflux transporter. When darolutamide was coadministered with itraconazole, a dual P-gp and potent CYP450 3A4 inhibitor, mean darolutamide peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 40% and 70%, respectively, compared to administration of darolutamide alone.

MANAGEMENT: Caution is advised when darolutamide is used with dual P-gp and potent CYP450 3A4 inhibitors. Patients should be monitored more frequently for adverse effects such as fatigue, hypertension, neutropenia and abnormal liver function tests, and the darolutamide dosage adjusted as necessary in accordance with the product labeling.

ADJUST DOSING INTERVAL: Administration of atazanavir with food enhances oral bioavailability and reduces pharmacokinetic variability. According to the manufacturer, administration with a light meal increased the peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of a single 400 mg dose of atazanavir by 57% and 70%, respectively, relative to the fasting state. Administration with a high-fat meal resulted in a mean increase of 35% in atazanavir AUC and no change in Cmax compared to fasting. The coefficient of variation of AUC and Cmax decreased by approximately one-half when given with either a light or high-fat meal compared to the fasting state.

MANAGEMENT: To ensure maximal oral absorption, atazanavir should be administered with or immediately after a meal.

ADJUST DOSING INTERVAL: Food enhances the oral absorption of darolutamide. According to the prescribing information, bioavailability of darolutamide increased by 2.0 to 2.5-fold when administered with food. A similar increase in exposure was observed for the active metabolite keto-darolutamide.

MANAGEMENT: Darolutamide should be administered with food.