Otilonium Bromide (Synonyms: Octylonium)

Octylonium bromide (SP63) is an antimuscarinic used as a spasmolytic agent.Target: mAChROctylonium bromide (SP63) inhibited the generation of ACh-induced calcium signals in a dose dependent manner (IC50=880 nM) [1]. Octylonium bromide (SP63), a clinically useful spasmolytic, behaves as a potent blocker of neuronal nicotinic acetylcholine receptors (AChR). Whole-cell Ba2+ currents (IBa) through Ca2+ channels of voltage-clamped chromaffin cells were blocked by otilonium with an IC50 of 6.4 microM. Octylonium bromide (SP63) inhibited the secretory responses induced by 10 s pulses of 50 microM DMPP with an IC50 of 7.4 nM [2]. Octylonium bromide (SP63) may represent an effective treatment for irritable bowel syndrome because it reduces its predominant symptom (abdominal pain/ discomfort) more than placebo does [3]. Octylonium bromide (SP63) is a spasmolytic agent that blocks L-Type Calcium channels in human colonic smooth muscle. Octylonium bromide (SP63) is safe, well tolerated and superior to placebo in reducing the frequency of abdominal pain, severity of abdominal bloating and protecting from symptom relapse in IBS. These results further confirm that patients with IBS can improve during and following treatment with otilonium bromide [4].

References:
[1]. Battaglia, G., et al., Otilonium bromide in irritable bowel syndrome: a double-blind, placebo-controlled, 15-week study. Aliment Pharmacol Ther, 1998. 12(10): p. 1003-10.
[2]. Clave, P., et al., Randomised clinical trial: otilonium bromide improves frequency of abdominal pain, severity of distention and time to relapse in patients with irritable bowel syndrome. Aliment Pharmacol Ther, 2011. 34(4): p. 432-42.
[3]. Lindqvist, S., et al., The colon-selective spasmolytic otilonium bromide inhibits muscarinic M(3) receptor-coupled calcium signals in isolated human colonic crypts. Br J Pharmacol, 2002. 137(7): p. 1134-42.
[4]. Gandia, L., et al., Otilonium: a potent blocker of neuronal nicotinic ACh receptors in bovine chromaffin cells. Br J Pharmacol, 1996. 117(3): p. 463-470.