Can I use BENTYL (dicyclomine) for abdominal pain?

Bentyl (Dicyclomine) for Abdominal Pain Management

Bentyl (dicyclomine) is recommended for treating abdominal pain specifically in patients with irritable bowel syndrome (IBS), but should not be used for general abdominal pain without a diagnosis. 1

Mechanism and Indication

Dicyclomine is an antispasmodic medication that works primarily through anticholinergic effects, helping to:

• Reduce smooth muscle contractions in the gastrointestinal tract
• Potentially decrease visceral hypersensitivity
• Relieve abdominal pain associated with IBS

The FDA has specifically approved dicyclomine for the treatment of functional bowel/irritable bowel syndrome 1, not for general abdominal pain of unknown origin.

Dosing and Administration

• Standard dosing: 10-20mg three times daily 2
• Maximum dosing: 40mg four times daily (160mg/day) 1
• For acute episodes: Can be used intermittently in response to periods of increased abdominal pain or cramps
• For regular symptoms (especially post-meal): Take before meals

Efficacy for IBS Pain

The American Gastroenterological Association (AGA) suggests using antispasmodics like dicyclomine in patients with IBS (conditional recommendation, low certainty in evidence) 3. Evidence shows:

• Antispasmodics demonstrated improvement in abdominal pain compared to placebo (RR 0.74; 95% CI 0.59-0.93) 3
• Dicyclomine specifically showed significant improvement in pain in clinical trials 3
• In a 2-week double-blind study, dicyclomine 40mg four times daily was superior to placebo in:
  • Improving overall condition
  • Decreasing abdominal pain and tenderness
  • Improving bowel habits 4

Side Effects and Cautions

Common anticholinergic side effects include:

• Dry mouth (33% of patients)
• Dizziness (40%)
• Blurred vision (27%)
• Nausea (14%)
• Somnolence (9%) 1

Important considerations:

• 9% of patients discontinue treatment due to side effects 1
• Regular use in constipation-predominant IBS may be limited due to anticholinergic effects 3
• Avoid intravenous administration due to risk of thrombosis 5
• Use with caution in elderly patients who may be more sensitive to anticholinergic effects 2

Alternative Treatments for IBS Pain

If dicyclomine is not tolerated or ineffective, consider:

1. Tricyclic antidepressants (TCAs): First-line for IBS pain management 2

   • Amitriptyline: Start 10mg at bedtime, titrate to 30-50mg
   • Desipramine/nortriptyline: 10-25mg at bedtime (lower anticholinergic effects)

2. Peppermint oil: Enteric-coated, 0.2-0.4mL three times daily 2

3. Other antispasmodics: Hyoscine (available in US) 3

When Not to Use Dicyclomine

• For general abdominal pain without a diagnosis
• In patients with severe constipation (may worsen)
• In elderly patients sensitive to anticholinergic effects
• For intravenous administration (risk of thrombosis) 5

Monitoring and Follow-up

• Assess response after 2-4 weeks of treatment
• If side effects occur, dose reduction may be necessary (from 160mg daily to average 90mg daily) 1
• Consider discontinuation if no improvement after adequate trial or if side effects are intolerable

Dicyclomine is most appropriate for patients with IBS-related abdominal pain, particularly when pain is associated with altered bowel habits. For non-IBS abdominal pain, proper diagnosis should be established before considering treatment with dicyclomine.