Nifedipin ve Kinidin etkileşimi

Co-administration of multiple doses of quinidine sulfate, 200 mg t.i.d., and nifedipine, 20 mg t.i.d., increased C max and AUC of nifedipine in healthy volunteers by factors of 2.30 and 1.37, respectively.

Monitoring of heart rate and adjustment of the nifedipine dose, if necessary, are recommended when quinidine is added to a treatment with nifedipine.

The exposure to quinidine was not importantly changed in the presence of nifedipine.

Cardiovascular Drugs Antiarrhythmics Quinidine: Quinidine is a substrate of CYP3A and has been shown to inhibit CYP3A in vitro .

Very rarely, and again by mechanisms not understood, quinidine levels are decreased by coadministration of nifedipine .

Presumably because both drugs are metabolized by cytochrome P450 IIIA4 , coadministration of quinidine causes variable slowing of the metabolism of nifedipine .

Interactions with other dihydropyridine calcium channel blockers have not been reported, but these agents (including felodipine, nicardipine, and nimodipine ) are all dependent upon P450 IIIA4 for metabolism, so similar interactions with quinidine should be anticipated.