Some aspects in the pharmacology of diclonium bromide (2-(3,2-dichloroanilino)quinolizinium bromide). Part I: Antispasmodic action.

Diclonium bromide (EU-2972; 2-(3,4-dichloroanilino)quinolizinium bromide) was demonstrated to possess an effective, prolonged inhibitory action on contractions in response to stimuli or propulsive movements in the lower bowel of the dog. The compound's antagonism to contractile activity was greater in the distal colon than in the duodenum or upper bowel. Diclonium bromide was a nonselective antispasmodic but, unlike papaverine, caused profound antagonism against smooth muscle contractile responses to intrinsic motor neural excitation. The drug had weak specific anticholinergic action, but its lack of antagonistic effect on other cholinergic responses in this study indicates that the anticholinergic action contributes very little, if at all, to its overall antispasmodic effect. The compound has potential application in the treatment of spastic-colon disease.