Acotiamide inhibited recombinant human and canine stomach-derived acetylcholinesterase (AChE) activity in vitro. The mode of the AChE inhibitory action of acotiamide was selective and reversible. It shows a mixed-type inhibition toward recombinant human AChE activity. Ki1 (competitive inhibition) and Ki2 values (noncompetitive inhibition) of acotiamide were 610 nM and 2.7 μM, respectively. IC50 values for AChE of acotiamide is 3 μM. IC50 value for BuChE of acotiamide is >1.0 × 10 M. Acotiamide inhibited AChE selectively, and the ratio of the IC50 value for BuChE to AChE was more than 330. Acotiamide has no affinity for α2-adrenoceptor, dopamine D2S receptor, or serotonin 5-HT4 receptors, including 5-HT4c, 5-HT4d, or 5-HT4e receptors. In in vitro studies, acotiamide enhanced acetylcholine- but not carbachol-induced contractile responses of guinea pig gastric antrum strips.
In vivo
Acotiamide stimulates gastric motility and improves gastric motility dysfunction in rats by inhibiting AChE activity. It improves stress-induced delayed gastric emptying in rats. Acotiamide also enhances gastric motility by inhibiting AChE activity without affecting QT interval in dogs.