BRETYLIUM TOSYLATE AS AN ANTIHYPERTENSIVE DRUG

In severely hypertensive patients ganglioplegic drugs exert a more predictable depressor effect than other antihypertensive agents. They are used infrequently in mildly hypertensive patients, because side-effects from parasympathetic blockade are too troublesome. A drug decreasing sympathetic overactivity without affecting parasympathetic function would be expected to have the hypotensive action of ganglioplegics without their unpleasant side-effects. Bretylium has this property. Studies by Boura and associates 1 have shown that bretylium selectively blocks the function of the peripheral sympathetic adrenergic nerves. This effect appears after systemic injection and when the nerves are bathed in bretylium-containing solutions. Results of pharmacological tests suggest that the mechanism of action is due to impairment of norepinephrine production by nerve endings. Parasympathetic function was not inhibited. Intravenously injected bretylium produced slight decreases in supine arterial pressure in normotensive and hypertensive human subjects; orthostatic hypotension was pronounced. Early clinical studies 1a showed orally given bretylium tosylate to be