Bethanidine sulfate and its ortho-chloro derivative (BW 392C60) are potent adrenergic neuron blockers exhibiting sympathomimetic effects similar to those of bromobenzamine and guanethidine in various animal models, particularly in cats. These compounds inhibit the release of norepinephrine during neural stimulation and enhance the responsiveness of smooth muscle to epinephrine and norepinephrine. Notably, bethanidine sulfate increases the pressor response to tyramine, although this effect diminishes with higher doses. Unlike guanethidine, bethanidine sulfate does not deplete pressor amines in the iris of cats following administration. Additionally, it temporarily suppresses autonomic cholinergic mechanisms and can cause transient neuromuscular paralysis at large doses, contrasting its long-term adrenergic neuron blocking effects.