Drug Interactions between aripiprazole and Duzallo

MONITOR: Coadministration with alcohol or other central nervous system (CNS) depressants may enhance the sedative effects of allopurinol and increase the likelihood and/or severity of central nervous system (CNS) side effects, such as drowsiness, somnolence, vertigo, and ataxia.

MANAGEMENT: Caution for increased CNS adverse effects is advised if allopurinol is coadministered with alcohol, other CNS depressants, or agents that cause dizziness or vertigo. Patients should not drive, operate machinery, or engage in hazardous activities requiring mental alertness and motor coordination until they know how the medications affect them.

MONITOR: Coadministration with inducers of CYP450 3A4 may decrease the plasma concentrations of aripiprazole and its active metabolite, dehydro-aripiprazole. Clinical and in vitro data indicate that aripiprazole is extensively metabolized in the liver primarily via three enzymatic pathways (dehydrogenation, hydroxylation, and N-dealkylation) mediated by CYP450 2D6 and 3A4. When aripiprazole 30 mg once daily was coadministered with the potent CYP450 3A4 inducer carbamazepine at 200 mg twice daily in schizophrenic patients, mean aripiprazole peak plasma concentration (Cmax) and systemic exposure (AUC) decreased by 68% and 73%, respectively, compared to administration of aripiprazole alone. Likewise, mean Cmax and AUC of dehydro-aripiprazole were decreased by 69% and 71%, respectively, in the presence of carbamazepine. The interaction has not been studied with other, less potent inducers.

MANAGEMENT: Pharmacologic response to aripiprazole should be monitored more closely whenever a CYP450 3A4 inducer is added to or withdrawn from therapy, and the aripiprazole dosage adjusted as necessary. The prescribing information for individual aripiprazole products should be consulted for specific recommendations regarding concomitant use with CYP450 3A4 inducers.