Drug Interaction Report

MONITOR: Coadministration with viloxazine may increase the plasma concentrations of drugs that are substrates of CYP450 3A4 and/or CYP450 2D6 leading to increased toxicity. The proposed mechanism is decreased clearance due to viloxazine-mediated inhibition of CYP450 3A4 and/or CYP450 2D6. The product labeling describes viloxazine as a weak inhibitor of CYP450 3A4 and CYP450 2D6.

MANAGEMENT: Caution is advised if viloxazine is used concomitantly with drugs that are substrates of CYP450 3A4 and/or CYP450 2D6, particularly those with a narrow therapeutic range. Monitor for adverse reactions of the CYP450 3A4 or CYP450 2D6 substrate and adjust dosages as needed.

ADJUST DOSING INTERVAL: Administration of alfuzosin with food enhances oral bioavailability. According to the manufacturer, extent of absorption is 50% higher when administered under fed conditions compared to fasting conditions.

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