Drug Interaction Report

Consumer information for this interaction is not currently available.

MONITOR: Coadministration with inducers of CYP450 3A4 may decrease the plasma concentrations of quinine, which is primarily metabolized by the isoenzyme. The interaction has been studied with rifampin, a potent CYP450 3A4 inducer, and treatment failures have been reported. In patients with uncomplicated Plasmodium falciparum malaria who received quinine sulfate 10 mg/kg concomitantly with rifampin 15 mg/kg/day for 7 days, the median quinine systemic exposure (AUC) between days 3 and 7 of therapy was 75% lower than that observed in patients who received quinine monotherapy. Likewise, in nine healthy subjects who received a single 600 mg oral dose of quinine sulfate following pretreatment with rifampin 600 mg/day for 2 weeks, the mean quinine peak plasma concentration (Cmax) and AUC decreased by 55% and 85%, respectively. The extent to which other, less potent inducers of CYP450 3A4 may interact with quinine is unknown.

MANAGEMENT: Caution is advised if quinine is used in combination with CYP450 3A4 inducers such as carbamazepine, phenobarbital, phenytoin, and St. John's wort. The possibility of diminished therapeutic efficacy should be considered.

Information for this minor interaction is available on the professional version.