Sotalol is a beta-
adrenoceptor blocking agent devoid of intrinsic
sympathomimetic activity, membrane stabilising actions and cardioselectivity. It lengthens repolarisation and the effective refractory period in all cardiac tissues independently of its antiadrenergic properties. Combining Class II and Class III antiarrhythmic properties,
sotalol can be given either intravenously or orally and its pharmacokinetic properties permit long dosing (once or twice daily) intervals. Controlled and uncontrolled studies have established the efficacy of
sotalol in mild-to-moderate
essential hypertension and in angina of effort.
Sotalol reduces anginal frequency and
glyceryl trinitrate (
nitroglycerin) consumption and increases exercise capacity during treadmill stress tests. In addition, although there is evidence that the
drug reduces reinfarction rate in survivors of acute
infarction, the data for reduction in
sudden death rates in these patients are not as compelling as for other beta-blockers. However, comparative and additional long term studies are required before an accurate assessment of the use of
sotalol in these disorders can be made. When used in the treatment of mild-to-moderate
hypertension sotalol is more effective than placebo and comparable to other beta-blockers in reducing elevated blood pressures. In addition, a synergistic
antihypertensive response is achieved when
sotalol is combined with
hydrochlorothiazide. Still, additional well-controlled comparative studies are required before the value of
sotalol relative to other
drug treatment regimens in the management of
hypertension can be made. In preliminary studies
sotalol appeared effective in most forms of supraventricular
tachyarrhythmias with its effects being similar to those of other beta-blockers. However, preliminary data indicate that
sotalol is likely to be more effective than than conventional beta-blockers in converting
atrial flutter and fibrillation to sinus rhythm and maintaining stability post-conversion.
Sotalol also appears to be a promising agent in the control of ventricular arrhythmias. In suppressing
premature ventricular contractions it is at least as effective as
procainamide. In
ventricular tachycardia and fibrillation, intravenous
sotalol (1.5 mg/kg), prevents reinduction by programmed electrical stimulation in 40 to 50% of cases if double stimuli are used. Both prevention of reinducible
arrhythmia and the suppression of spontaneous arrhythmias on Holter recordings are predictive of a long term favourable clinical outcome. In patients with reduced ejection fractions,
sotalol depresses ventricular function less than conventional beta-blockers.(ABSTRACT TRUNCATED AT 400 WORDS)