Drug Interaction Report

GENERALLY AVOID: Coadministration with potent inducers of CYP450 3A4 may decrease the plasma concentrations of fruquintinib, which is primarily metabolized by the isoenzyme. Concomitant use with rifampin, a potent CYP450 3A4 inducer, decreased fruquintinib peak plasma concentration (Cmax) and systemic exposure (AUC) by 12% and 65%, respectively. Reduced efficacy of fruquintinib may occur.

MANAGEMENT: Coadministration of fruquintinib with potent CYP450 3A4 inducers should be avoided.

ADJUST DOSING INTERVAL: Administration with food may increase the oral bioavailability of rifapentine and reduce the incidence of gastrointestinal adverse events. Administration with a high fat meal typically increases rifapentine's maximum concentration (Cmax) and systemic exposure (AUC) by approximately 40% to 50% over that observed when rifapentine is administered under fasting conditions. Rifapentine is often prescribed in combination with isoniazid. When single doses of rifapentine (900 mg) and isoniazid (900 mg) were administered with a low fat, high carbohydrate breakfast, the Cmax and AUC of rifapentine increased by 47% and 51%, respectively. On the other hand, isoniazid's Cmax and AUC decreased by 46% and 23%, respectively.

MANAGEMENT: Products containing oral rifapentine as the sole ingredient recommend administration with a meal to increase bioavailability and reduce the occurrence of gastrointestinal upset, nausea, and/or vomiting. Consultation of product labeling for combination products and/or relevant guidelines may be helpful if rifapentine is combined with a medication that is typically taken on an empty stomach.