Disopyramide anticholinergic action.

The effect of disopyramide on cholinergic transmission has been studied using the frog isolated abdominis rectus preparation and the guinea pig isolated vas deferens hypogastric nerve preparation. Disopyramide (2 X 10(-5) mol litre-1) reduced the response of the abdominis rectus to carbachol (1.36 X 10(-6)--4.8 X 10(-5) mol litre-1). Furthermore, disopyramide (1 X 10(-6)--3 X 10(-4) mol litre-1) produced a concentration-dependent reduction in the response to carbachol (5.46 X 10(-6) mol litre-1). The response to potassium chloride (3.34 X 10(-2) mol litre-1) was unaltered by disopyramide (1 X 10(-6)--3 X 10(-4) mol litre-1). Disopyramide produced a dose-related ganglionic blockade at concentrations greater than 2 X 10(-5) mol litre-1. Complete blockade to ganglionic transmission occurred at 3 X 10(-4) mol litre-1 disopyramide.