Topical diltiazem and bethanechol decrease anal sphincter pressure without side effects.

Abstract

BACKGROUND: Topical nitrates lower anal sphincter pressure and heal anal fissures, but a majority of patients experience headache. The internal anal sphincter has a calcium dependent mechanism to maintain tone, and also receives an inhibitory extrinsic cholinergic innervation. It may therefore be possible to lower anal sphincter pressure using calcium channel blockers and cholinergic agonists without side effects. AIMS: To investigate the effect of oral and topical calcium channel blockade and a topical cholinomimetic on anal sphincter pressure. METHODS: Three studies were conducted, each involving 10 healthy volunteers. In the first study subjects were given oral 60 mg diltiazem or placebo ..