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

• Published in: Human psychopharmacology Vol. 7; no. 3; pp. 199 - 204
• Main Authors: Yeragani, Vikram K., Pohl, Robert, Balon, Richard, Ramesh, C., Berchou, Richard
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.05.1992
• Subjects: central; cholinergic; heart rate; Muscarinic; posture; R-R variance
• ISSN: 0885-6222; 1099-1077
• DOI: 10.1002/hup.470070307

To examine the anticholinergic effects of scopolamine, postural tests were performed in nine healthy male volunteers after they received intravenous infusions of 0.2mg 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.