Drug Interaction Report

Coadministration with inhibitors of CYP450 2C9 may increase the serum levels and effects of carvedilol. The mechanism is inhibition of CYP450 2C9, one of the primary isoenzymes involved in the metabolism of carvedilol. According to the prescribing information, CYP450 2C9 is thought to be of importance in the O-methylation pathway of S(-)-carvedilol. Further reductions in heart rate or cardiac conduction may occur.

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

MANAGEMENT: Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.