What is Clinidium?

What is Clidinium?

Clidinium bromide (N-methyl-quinuclidinyl-benzylate) is a quaternary ammonium antimuscarinic (anticholinergic) drug used primarily as an antispasmodic agent for gastrointestinal disorders, most commonly marketed in combination with chlordiazepoxide for irritable bowel syndrome. 1

Mechanism of Action

• Clidinium works by blocking muscarinic receptors, producing antimuscarinic effects that reduce gastrointestinal smooth muscle spasm 1
• It delays gastric emptying in a dose-dependent manner when given orally at therapeutic doses 2
• At 5 mg doses, clidinium delays gastric emptying to the same extent as 15 mg propantheline bromide but with less suppression of salivary secretion 2

Clinical Applications

Primary indication: Clidinium is used as an antispasmodic in irritable bowel syndrome, typically combined with chlordiazepoxide (an anxiolytic) 1, 3

Functional dyspepsia: When used as add-on therapy to proton pump inhibitors in refractory functional dyspepsia:

• Response rate of 41% (defined as >50% reduction in symptoms) versus 5% with placebo at 4 weeks 4
• Significantly improves quality of life compared to placebo 4
• Standard therapy with clidinium/chlordiazepoxide showed 78.3% effectiveness in irritable bowel syndrome trials, particularly beneficial in the painful form of IBS 3

Dosing and Administration

• Typical therapeutic doses range from 2.5-5 mg orally 2
• Usually administered in combination with chlordiazepoxide 1, 3
• The combination is given as add-on therapy for 4 weeks in functional dyspepsia protocols 4

Adverse Effects and Safety

Common side effects:

• Drowsiness occurs in approximately 30% of patients (versus 7% with placebo) 4
• Antimuscarinic toxicity can occur with overdose, presenting with dilated pupils and sinus tachycardia that may persist for 11+ hours 1
• Gastrointestinal side effects are the most significant concern 5

Important safety consideration: Emergency physicians should be aware of potential antimuscarinic toxicity in patients using illicit chlordiazepoxide who may inadvertently overdose on clidinium 1

Clinical Efficacy Limitations

• Long-term follow-up (>6 months) shows that clidinium-based therapy is no better than placebo in limiting relapse of IBS symptoms 3
• In gas-predominant IBS, clidinium therapy shows similar effects to placebo 3
• No major adverse events reported in controlled trials 4