otilonium-bromide

Description: Otilonium bromide (SP-63; Octylonium bromide; SP63; trade name Spasmomen among others) is a potent anti-muscarinic agent and a CCB (calcium channel blocker) used to relieve spasmodic pain of the gut, in particular in irritable bowel syndrome. Otilonium bromide is a quaternary ammonium compound whose spasmolytic action, selective on the distal gastrointestinal tract, is mainly due to its direct myolytic properties. This drug modifies Ca2+ fluxes from extracellular and intracellular pools in the intestinal smooth muscle and is poorly absorbed, thus it exerts its action locally, without any considerable systemic effect.

References: Arch Int Pharmacodyn Ther. 1983 Aug; 264(2):305-23; Aliment Pharmacol Ther. 1998 Oct; 12(10):1003-10.