Drug Interaction Report

MONITOR: Coadministration with inducers of CYP450 3A4 may decrease the plasma concentrations of isavuconazole, which is primarily metabolized by CYP450 3A4 and 3A5 and subsequently by uridine diphosphate glucuronosyltransferases (UGT). When multiple doses of isavuconazonium sulfate (prodrug of isavuconazole) were administered to healthy volunteers with multiple doses of the potent CYP450 3A4 inducer rifampin (600 mg), mean isavuconazole peak plasma concentration (Cmax) and systemic exposure (AUC) decreased by 75% and 97%, respectively. The extent to which other, less potent inducers of CYP450 3A4 may interact with isavuconazole is unknown.

MANAGEMENT: Caution is advised during concomitant use of isavuconazonium sulfate with CYP450 3A4 inducers. The potential for decreased efficacy of isavuconazonium sulfate should be considered.

ADJUST DOSING INTERVAL: According to product labeling, the bioavailability of deferasirox was variably increased when taken with a meal.

MANAGEMENT: To ensure consistent plasma drug levels, deferasirox should be taken on an empty stomach 30 minutes before eating preferably at the same time everyday.