Drug Interaction Report

MONITOR: Coadministration with inducers of CYP450 2C9 may decrease the plasma concentrations of celecoxib, which is primarily metabolized by the isoenzyme. When a single 200 mg dose of celecoxib was administered to 12 healthy volunteers following pretreatment with the moderate CYP450 2C9 inducer rifampin 600 mg once daily for 5 days, celecoxib peak plasma concentration (Cmax) and systemic exposure (AUC) decreased by 56% and 64%, respectively, while clearance increased by 185%. Reduced efficacy of celecoxib may occur.

MANAGEMENT: The potential for diminished pharmacologic effects of celecoxib should be considered during coadministration with CYP450 2C9 inducers. Dose adjustments or alternative treatments may be required if an interaction is suspected.

GENERALLY AVOID: Concurrent acute use of barbiturates and ethanol may result in additive CNS effects, including impaired coordination, sedation, and death. Tolerance of these agents may occur with chronic use. The mechanism is related to inhibition of microsomal enzymes acutely and induction of hepatic microsomal enzymes chronically.

MANAGEMENT: The combination of ethanol and barbiturates should be avoided.