Anticholinergic effects and passage through the intestinal wall ofN-butylhyoscine bromide

Abstract

AbstractThe effects of N-butylhyoscine bromide (Buscopan) were examined on responses of guinea-pig isolated intestine to transmural stimulation and to peristalsis induced by raising the intraluminal pressure. The drug acted rapidly and in low concentration to abolish peristaltic activity and responses to transmural stimulation when applied to the serosal surface of the ileum, but from 100 to 1000 times the concentration was required when it was applied to the mucosal surface. The effects were more persistent after mucosal than after serosal application. N-Butylhyoscine bromide was bound to mucus and mucosal material, the ratio of free to bound drug being 2:1. The drug passed through portions of the intestinal wall containing Peyer’s patches more rapidly than through portions containing no macroscopically visible lymphoid tissue. The rate of passage through Peyer’s patches, but not through other portions, increased with increasing hydrostatic pressure. These findings help to explain why enterally administered N-butylhyoscine bromide exerts anti-cholinergic effects on the gut without producing systemic actions.