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.

ADJUST DOSING INTERVAL: Certain penicillins may exhibit reduced gastrointestinal absorption in the presence of food. The therapeutic effect of the antimicrobial may be reduced.

MANAGEMENT: The interacting penicillin should be administered one hour before or two hours after meals. Penicillin V and amoxicillin are not affected by food and may be given without regard to meals.