Drug Interactions between amoxicillin / clarithromycin / vonoprazan and darolutamide

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.

Although some in vitro data indicate synergism between macrolide antibiotics and penicillins, other in vitro data indicate antagonism. When these drugs are given together, neither has predictable therapeutic efficacy. Data are available for erythromycin, although theoretically this interaction could occur with any macrolide. Except for monitoring of the effectiveness of antibiotic therapy, no special precautions appear to be necessary.