Bretylium Tosylate

**Semantic type:** Pharmacologic Substance

**Definition:** The tosylate salt form of bretylium, a quaternary ammonium salt and non-selective adrenergic neuronal blocking agent with anti-arrhythmic properties. Bretylium tosylate is selectively taken up into peripheral nerve terminals and initially causes a release of norepinephrine from sympathetic nerve endings, thereby causing a sympathomimetic effect. This is followed by a prolonged anti-adrenergic action which prevents further discharge of neurotransmitter from sympathetic nerve endings. Its myocardial effects include a prolongation of action potential as well as refractory period. This drug is used to treat and suppress ventricular arrhythmias, particularly ventricular fibrillation and ventricular tachycardia.

**Synonyms:** - (o-Bromobenzyl)ethyldimethylammonium p-Toluenesulfonate - 2-Bromo-N-ethyl-N,N-dimethylbenzenemethanaminium 4-Methylbenzenesulfonate - BRETYLIUM TOSYLATE - Bretylol - Darentin