Reversal of antihypertensive agent-induced postural hypotension with physostigmine.

Physostigmine, administered intravenously, reversed postural hypotension induced by hypotensive agents, guanethidine, clonidine and dopamine2-receptor agonists. Postural hypotension, induced by pentobarbital sodium, was also reversed by physostigmine. Neostigmine reversed postural hypotension induced by clonidine following intracerebroventricular, but not intravenous administration. It is proposed that centrally acting cholinomimetic agents may be used to manage postural hypotension resulting from suppression of sympathetic nervous system activity.