Interaksi Prokainamid dan Kuinidin

Considering the known proarrhythmic properties of procainamide and the lack of evidence of improved survival for any antiarrhythmic drug in patients without life-threatening arrhythmias, the use of procainamide as well as other antiarrhythmic agents should be reserved for patients with life-threatening ventricular arrhythmias.

Anticholinergic drugs administered concurrently with PA may produce additive antivagal effects on A-V nodal conduction, although this is not as well documented for PA as for quinidine.

Concurrent Other Antiarrhythmic Agents Concurrent use of PA with other Group 1A antiarrhythmic agents such as quinidine or disopyramide may produce enhanced prolongation of conduction or depression of contractility and hypotension, especially in patients with cardiac decompensation.

Drug Interactions If other antiarrhythmic drugs are being used, additive effects on the heart may occur with PA administration, and dosage reduction may be necessary (see WARNINGS ).

Proarrhythmic effects Like many other drugs (including all other Class Ia antiarrhythmics), quinidine prolongs the QT c interval, and this can lead to torsades de pointes , a life-threatening ventricular arrhythmia (see OVERDOSAGE ).

Perhaps by competing for pathways of renal clearance, coadministration of quinidine causes an increase in serum levels of procainamide .