Drug Interaction Report

MONITOR: Coadministration with inducers of CYP450 2C9 may decrease the plasma concentrations of lesinurad. According to the manufacturer, administration of lesinurad with the potent CYP450 inducer rifampin (600 mg daily) decreased lesinurad peak plasma concentration (Cmax) and systemic exposure (AUC) by approximately 25% and 40%, respectively, compared to administration of lesinurad alone.

MANAGEMENT: The potential for diminished pharmacologic effects of lesinurad should be considered during coadministration with CYP450 2C9 inducers. Alternative treatments may be required if an interaction is suspected.

ADJUST DOSING INTERVAL: The tolerability of allopurinol may be improved by giving it after a meal. Additionally, when the dose is greater than 300 mg, dividing the total daily dose into smaller doses administered more often may be appropriate to help minimize gastrointestinal irritation.

MONITOR: Concomitant use of allopurinol with central nervous system (CNS) depressants, including alcohol, may potentiate adverse effects such as somnolence and sedation.

MANAGEMENT: To improve tolerability, some manufacturers suggest administering allopurinol after a meal. Additionally, if the daily dose is greater than 300 mg, administering allopurinol in divided doses may help reduce gastrointestinal intolerance. Patients should also be counseled to avoid or limit consumption of alcohol and to avoid activities requiring mental alertness such as driving or operating hazardous machinery until they know how the medication affects them.