[Pharmacodynamics of allapinin and its possible adverse effects].

Allapinine (Class IC), a new antiarrhythmic agent, was studied in 76 patients with premature contraction. Allapinine was found to be beneficial both in ventricular and supraventricular premature beats. Oral allapinine usually showed its effect 40-60 minutes following its administration, its maximum action being 4-5 hours later, its duration was some 8 hours. The optimal dose of the drug amounted to 75 mg/day. Larger-dose allapinine produced adverse effects, its lower dosage had no antiarrhythmic effect. The drug failed to affect blood pressure, heart rate, QT interval length. The PQ interval and QRS complex were increased. The side effects were dose-dependent. There was a risk of the drug's arrhythmogenic effect.