Drug Interaction Report

GENERALLY AVOID: Coadministration with moderate or weak inducers of CYP450 3A4 may reduce the plasma concentrations of cobicistat, which is primarily metabolized by the isoenzyme. The clinical significance is unknown.

MANAGEMENT: Given the risk of reduced viral susceptibility and resistance development associated with subtherapeutic antiretroviral drug levels, concomitant use of antiretroviral regimens containing cobicistat with these inducers should be avoided. Alternative treatment combinations that do not include metabolic inducers should be considered whenever possible. If concomitant use is required, close clinical and laboratory monitoring of antiretroviral response is recommended.

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.