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

Abstract

Bretylium tosylate blocked the Valsalva "overshoot" and the digital vasoconstrictor response to a deep breath in doses of 150 mg intravenously in man. The cold pressor response was not completely blocked at this level. Parasympathetic blocking effects were entirely absent. Absorption after oral administration was poor, the effective oral dose averaging approximately 15 times more than the effective intravenous dose. The duration of action after an oral dose was about 8 hours. In comparison with guanethidine for the treatment of hypertension bretylium was less potent but did not produce diarrhea and initial regulation was easier to obtain because of the shorter duration of action. Tenderness in the region of the parotid glands was a side effect of bretylium tosylate.