Drug Interaction Report

MONITOR: Coadministration with nefazodone may increase the plasma concentrations of drugs that are substrates of the CYP450 3A4 isoenzyme. The mechanism is decreased clearance due to inhibition of CYP450 3A4 activity by nefazodone.

MANAGEMENT: Caution is advised if nefazodone must be used concomitantly with medications that undergo metabolism by CYP450 3A4, particularly those with a narrow therapeutic range. A lower initial dosage, as well as clinical and laboratory monitoring, may be appropriate for some drugs.

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.