How does quinidine sulfate interact with other medications?

Quinidine sulfate can interact with many medications. Tell your doctor if you are taking any of the following: other medications to treat irregular heartbeats, beta-blockers, a tricyclic antidepressant, phenothiazine, pimozide, itraconazole, ziprasidone, voriconazole, thioridazine, mesoridazine, ritonavir, dolasetron, digoxin, warfarin, erythromycin, sparfloxacin, levofloxacin and gatifloxacin. Your doctor may need to adjust your dosage or discontinue use of these medications to safely use quinidine sulfate.