Quinidine Aripiprazole

Concomitant use with potential CYP2D6 inhibitors - During coadministration of potential CYP2D6 inhibitors such as quinidine, fluoxetine, or paroxetine with aripiprazole, reduce the aripiprazole dose to at least one-half of its normal dose. 

Drugs that may be affected by itraconazole include alfentanil, almotriptan, alprazolam, amphotericin B, aripiprazole, benzodiazepines, buspirone, busulfan, calcium blockers, carbamazepine, cilostazol, cisapride, corticosteroids, cyclosporine, digoxin, disopyramide, docetaxel, dofetilide, eletriptan, epierenone, ergot alkaloids, haloperidol, HMG-CoA reductase inhibitors, hydantoins (phenytoin), hypoglycemic agents, oral midazolam, phosphodiesterase type 5 inhibitors, pimozide, polyenes, protease inhibitors, quinidine, rifamycins, sirolimus, tacrolimus, tolterodine, triazolam, trimetrexate, vinca alkaloids, warfarin, and zolpidem. 

Modest elevations of aripiprazole serum concentration occur in the presence of ketoconazole or quinidine, which inhibit CYP 2D6 and 3A4, respectively. Carbamazepine has been reported to decrease aripiprazole serum concentrations. ... 

Aripiprazole plasma levels are increased by inhibitors, and decreased by inducers, of CYP3A4. Quinidine increases aripiprazole levels. The manufacturers advise caution with drugs that can prolong the QT intervaL Food and famotidine do not have a clinically relevant effect on the pharmacokinetics of aripiprazole, and aripiprazole does not affect the pharmacokinetics of dextromethorphan, omeprazole, and warfarin. 

Quinidine, an inhibitor of CYP2D6, has been found to increase the AUC of aripiprazole by 107%, although the maximum concentration was unchanged. It is recommended that the dose of aripiprazole is halved if given concomitantly with quinidine. - ... 

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