Drug Interaction Report

MONITOR: Coadministration with inducers of CYP450 3A4 may decrease the plasma concentrations of bedaquiline, which is primarily metabolized by CYP450 3A4 to the major N-monodesmethyl metabolite, M2. Because M2 is 4- to 6-fold less active than the parent drug in terms of antimycobacterial potency, the interaction may diminish the therapeutic effect of bedaquiline. In healthy volunteers, administration of a single 300 mg dose of bedaquiline in combination with the potent CYP450 3A4 inducer rifampin (600 mg once daily for 21 days) reduced bedaquiline systemic exposure (AUC) by 52% compared to administration alone. No data are available for use with other, less potent CYP450 3A4 or P-gp inducers.

MANAGEMENT: Caution is advised when bedaquiline is used in combination with inducers of CYP450 3A4 due to the potential for reduced antimycobacterial effect.

GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of rufinamide. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

ADJUST DOSING INTERVAL: Food enhances the oral absorption and bioavailability of rufinamide. In healthy volunteers, administration of a single 400 mg dose of rufinamide with food resulted in an approximately 56% increase in mean peak plasma concentration (Cmax) and a 34% increase in systemic exposure (AUC) compared to administration during a fasting state.

MANAGEMENT: To ensure maximal oral absorption, it is preferable to administer rufinamide with food. Patients receiving rufinamide should be advised to avoid consumption of alcohol. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how rufinamide affects them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.

ADJUST DOSING INTERVAL: Food enhances the oral bioavailability of bedaquiline. When administered with a standard meal containing approximately 22 grams of fat (558 total Kcal), the relative bioavailability of bedaquiline increased by approximately 2-fold compared to administration under fasted conditions.

GENERALLY AVOID: Coadministration with alcohol may increase the risk of hepatotoxicity associated with the use of bedaquiline. In clinical trials, hepatic adverse drug reactions developed in more bedaquiline-treated patients than in those who received other drugs used to treat tuberculosis. In patients receiving bedaquiline or placebo in combination with other drugs used to treat multidrug-resistant tuberculosis, reversible aminotransferase elevations of at least 3 times the upper limit of normal developed more frequently in the bedaquiline treatment group [10.8%] than in the placebo group [5.7%].

MANAGEMENT: To ensure maximal oral absorption, bedaquiline should be taken with food. Patients should avoid alcohol use during treatment.