Effects of scopolamine on immediate postural changes in heart rate and R—R variance in humans

Abstract

To examine the anticholinergic effects of scopolamine, postural tests were performed in nine healthy male volunteers after they received intravenous infusions of 0.2 mg of scopolamine, 0.4 mg of glycopyrrolate, or placebo on separate days under double-blind randomized conditions. Compared to the placebo and glycopyrrolate conditions, scopolamine produced a significantly exaggerated HR response to standing from supine posture. Scopolamine also produced a significant increase in R-R variance during supine deep breathing and standing conditions as compared to glycopyrrolate and placebo conditions. At the same time, scopolamine also produced a significant dry mouth. These findings suggest that the effects of scopolamine in low doses on the above cardiac variables are vagomimetic.

Tropane alkaloids

“…143 Scopolamine affects immediate postural changes in heart rate and R-R variance in humans. 144 The cognitive behavioural and physiological effects of high dose thyrotropin-releasing hormone, TRH, both alone and following an administration of scopolamine, have been studied in 10 Alzheimer's disease patients. In the group of older volunteers TRH did not attenuate scopolamine-induced cognitive impairment, contrary to younger volunteers.…”