Moxaprindine in the acute treatment of ventricular arrhythmias in patients with cardiovascular disease.

The antiarrhythmic activity of intravenous moxaprindine was evaluated in 26 patients with cardiovascular disease; the mean maximum dose was 2.5 +/- 0.12 mg/kg. Ventricular extopics were completely abolished in 19 patients and significantly reduced in four patients, but were not favourably affected in three patients. In one patient with numerous runs of ventricular tachycardia, normal sinus rhythm was restored. Coupled ventricular ectopic activity always completely disappeared. At the maximum dose, the PR-interval (+27.7 +/- 3.3%), the QRS-duration (+24.6 +/- 2.2%), the QT-interval (+17.0 +/- 1.5%) and the QTc-interval (+10.8 +/- 1.2%) were significantly prolonged. The QRS morphology essentially remained unchanged. Moxaprindine caused first degree atrioventricular block in eight patients. The sinus rate was slowed at every dosage level. Nevertheless, moxaprindine could safely be administered to patients with dysfunction of the specialized conduction system, or with a damaged myocardium. Serious side effects did not occur. Moxaprindine is a promising new antiarrhythmic drug for the treatment of ventricular arrhythmias, but its value and safely in the chronic oral treatment of these arrhythmias remain to be established.