Bretylium Tosylate



Bretylium tosylate initially releases norepi­nephrine stores from adrenergic nerve terminals but subsequently prevents further norepinephrine release. This initial catecholamine release may ag­gravate some arrhythmias and produce transient hypertension. Although the chemical sympathec-tomy-like state may be antiarrhythmic, other elec­trophysiological properties may also contribute to the antiarrhythmic properties of bretylium. Bre­tylium does not depress myocardial contractility or affect vagal reflexes. After the initial increase in blood pressure, the drug may subsequently cause hypotension, usually orthostatic and con­trolled if the patient is supine. Bretylium is poorly absorbed orally and is commonly administered intravenously. Bretylium has been reported to in­duce spontaneous termination of ventricular fi­brillation. Bretylium is indicated in patients with life-threatening ventricular arrhythmias that have not responded to lidocaine and possibly to other drugs.