Drug Interaction Report

ADJUST DOSE: Coadministration with quinidine or other potent inhibitors of CYP450 2D6 may significantly increase the plasma concentrations of aripiprazole, which is partially metabolized by the isoenzyme. According to the product labeling, administration of aripiprazole (10 mg single dose) following pretreatment with quinidine (166 mg/day for 13 days) resulted in a 112% increase in aripiprazole systemic exposure (AUC) compared to administration of aripiprazole alone. The AUC of its active metabolite, dehydro-aripiprazole, was decreased by 35% in the presence of quinidine.

MANAGEMENT: Pharmacologic response to aripiprazole should be monitored more closely whenever quinidine or other potent inhibitors of CYP450 2D6 (e.g., fluoxetine, paroxetine, cinacalcet) are added to or withdrawn from therapy. The manufacturer recommends that aripiprazole dosage be reduced to one-half the normal dosage during concomitant administration with quinidine, and additional dosage adjustments be made based on clinical evaluation. Although clinical data are lacking, similar dosage adjustments may be appropriate during coadministration with other potent CYP450 2D6 inhibitors. Aripiprazole dosage should be increased accordingly if these agents are discontinued.

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.

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.