Selective Inhibition of the Sympathetic Nervous System in Man with Bretylium Tosylate, a New Antihypertensive Agent

BOURA and his associates have denmonstrated that bretylium tosylate (Darenthin) * produces a selective block of the sympathetic nervous system.' This beiizyl quaternary ammoniium compound appears to accumulate preferentially in peripheral sympathetic neurones. Unlike adrenergic blocking agents the effects of released or injected epinephrine and norepinephrine are not antagonized, and unlike ganglion-blocking drugs the parasympathetic nervous system is not inihibited at therapeutic dose levels of bretylium.1 Clinical trials in hypertensive patients indicate that orally administered bretylium tosylate causes a predominantly orthostatic fall of blood pressure comparable to that achieved with the ganglion-blocking drugs but without the side effects of parasympathetic blockade. 2 The following report summarizes our experience to date with this new agent.