Disopyramide phosphate was administered intravenously to 57 patients with 60 episodes of
arrhythmia (21 supraventricular and 39 ventricular)
as a 2 mg/kg bolus. Conversion to sinus rhythm was achieved in three (38 percent) of eight patients with
atrial flutter, two (20 percent) of ten patients with
atrial fibrillation, one (33 percent) of three patients with paroxysmal atrial
tachycardia, and two (50 percent) of four patients with sustained
ventricular tachycardia. In nine (75 percent) of 12 patients with
nonsustained ventricular tachycardia, suppression of the
arrhythmia was accomplished following the intravenous bolus of
disopyramide. In 18 (78 percent) of 23 patients with frequent ventricular premature contractions, greater than 50 percent suppression of the ventricular premature contractions was achieved. These effects were satisfactorily maintained in six (86 percent) of seven patients with
nonsustained ventricular tachycardia and in 14 (88 percent) of 16 patients with frequent ventricular premature contractions in whom
therapy with
disopyramide phosphate was continued as a 20 mg/hour
intravenous drip infusion for up to 24 hours. Side effects were observed in only eight patients (14 percent) and were primarily
anticholinergic in nature. Transient
hypotension, not necessitating treatment with pressor agents, was observed in three patients (5 percent), in two of whom discontinuance of
therapy with
disopyramide was deemed necessary. Intravenous
therapy with
disopyramide in the dosage regimen employed appears to be moderately effective against supraventricular
arrhythmia and particularly effective against ventricular
arrhythmia with minimal toxicity. It appears to be a suitable alternative to intravenous
therapy with
lidocaine and has the additional advantage of availability for
oral administration.