Intestinal antispasmodic, quaternary ammonium compound
ATC code: A03AB06 (Otilonium bromide)
A quaternary ammonium compound with triple action: blocks NK2 tachykinin receptors in intestinal smooth muscle, competitively inhibits muscarinic M-cholinergic receptors, and reduces calcium entry into smooth-muscle cells. Systemic bioavailability is under 5% – the action is mostly local, with minimal systemic anticholinergic effects.
First line
First-line for pain-predominant irritable bowel syndrome per 2021, 2021, and Rome IV. The Ford 2014 meta-analysis of 23 RCTs reported relative risk for no response on antispasmodics of 0.68 (95% CI 0.57–0.81). Standard dose 40 mg 2–3 times daily, 20 minutes before meals. Course 4–8 weeks with the option to repeat.
The drug is promoted for these uses outside international guidelines. Each entry below is analyzed against AEMPS, FDA, EMA, Cochrane and major RCTs.
Not recommended
Otilonium bromide is an antimuscarinic and calcium-blocking spasmolytic with local action in the gut. It is prescribed for irritable bowel syndrome and GI smooth muscle spasms (AEMPS Ficha Técnica). For biliary dyskinesia, otilonium bromide is occasionally prescribed in Russia and the CIS. Biliary dyskinesia as an independent diagnosis is rarely used in international medicine – more often functional gallbladder and sphincter of Oddi disorders are differentiated per Rome IV criteria. In people with ordinary right-upper-quadrant discomfort without confirmed biliary pathology, otilonium bromide is not indicated. The drug is relatively safe but can cause dry mouth, blurred vision, palpitations, and allergic reactions. If otilonium bromide was prescribed for biliary dyskinesia, consider seeking a second opinion.
Opens the checker prefilled with this drug. Pick the second one from your regimen.
Limited pregnancy data. When an antispasmodic is needed for IBS in pregnancy, mebeverine with more data is preferred.
Systemic bioavailability is low; milk transfer is minimal. Lactation use is acceptable when indicated.
Reference information, not a clinical decision. Discuss feeding pauses or changes with your physician or an IBCLC.
Otilonium bromide is evaluated for the following indications with varying evidence strength: Irritable bowel syndrome (evidence tier B), Biliary dyskinesia (evidence tier F). See the full indication matrix with dosing and citations above on this page.
Common side effects of Otilonium bromide (≥ 1 in 100): Dry mouth (uncommon given low systemic bioavailability), Constipation, Nausea, Headache. See the Safety section for uncommon and serious reactions.
FDA category B. Limited pregnancy data. When an antispasmodic is needed for IBS in pregnancy, mebeverine with more data is preferred.
Systemic bioavailability is low; milk transfer is minimal. Lactation use is acceptable when indicated.
Otilonium bromide is contraindicated in: Otilonium hypersensitivity; Angle-closure glaucoma; Prostatic hyperplasia with urinary retention; Pyloric stenosis. Full list in the Safety section.