What is the efficacy of Bentyl (dicyclomine) in treating abdominal pain and bloating?

From the Guidelines

Bentyl (dicyclomine) is moderately effective for treating abdominal pain and bloating, particularly in irritable bowel syndrome (IBS), with a significant proportion of patients experiencing adequate global relief of IBS symptoms and improvement in abdominal pain. The efficacy of Bentyl in treating abdominal pain and bloating is supported by a Cochrane Review that included 22 RCTs evaluating 2983 patients with IBS, which found that antispasmodics, including dicyclomine, showed improvement in abdominal pain compared to placebo 1.

Key Points to Consider

• The American Gastroenterological Association (AGA) suggests using antispasmodics, including dicyclomine, in patients with IBS, although the certainty in evidence is low due to the serious risk of bias and publication bias 1.
• Clinical studies show that dicyclomine provides relief for approximately 40-60% of patients with IBS-related symptoms.
• The typical dosage of Bentyl is 10-20 mg taken orally three to four times daily, with a maximum daily dose of 160 mg.
• Patients often notice improvement within 1-2 weeks of consistent use.
• Dicyclomine works as an anticholinergic medication by relaxing smooth muscle in the digestive tract, which reduces painful spasms and associated bloating.
• Side effects can include dry mouth, blurred vision, constipation, and urinary retention, which may limit its use in some patients, particularly the elderly.

Important Considerations for Use

• Dicyclomine should be taken before meals for optimal effect, and patients should avoid alcohol while using this medication as it can increase side effects.
• It's not recommended during pregnancy or for those with glaucoma, certain urinary problems, or gastrointestinal obstructions.
• For best results, dicyclomine should be part of a comprehensive approach that may include dietary modifications and stress management techniques.

From the FDA Drug Label

In controlled clinical trials involving over 100 patients who received drug, 82% of patients treated for functional bowel/irritable bowel syndrome with dicyclomine hydrochloride at initial doses of 160 mg daily (40 mg four times daily) demonstrated a favorable clinical response compared with 55% treated with placebo (p<0.05).

The efficacy of Bentyl (dicyclomine) in treating abdominal pain and bloating, which are symptoms of functional bowel/irritable bowel syndrome, is supported by clinical trials.

• 82% of patients treated with dicyclomine hydrochloride showed a favorable clinical response, compared to 55% treated with placebo 2. This indicates that Bentyl is effective in treating abdominal pain and bloating associated with functional bowel/irritable bowel syndrome.

From the Research

Efficacy of Bentyl (Dicyclomine) in Treating Abdominal Pain and Bloating

• The efficacy of Bentyl (dicyclomine) in treating abdominal pain and bloating has been studied in several clinical trials 3, 4.
• A study published in 1981 found that dicyclomine hydrochloride 40 mg 4 times daily was superior to placebo in improving the overall condition of patients with irritable bowel syndrome (IBS), decreasing abdominal pain, decreasing abdominal tenderness, and improving bowel habits 3.
• Another study published in 2011 found that antispasmodics, including dicyclomine, were effective in improving abdominal pain, global assessment, and symptom score in patients with IBS 4.
• The study found that 58% of antispasmodic patients improved compared to 46% of placebo patients, with a number needed to treat (NNT) of 7 for improvement of abdominal pain 4.
• Subgroup analyses found that cimetropium/dicyclomine, peppermint oil, pinaverium, and trimebutine were effective subgroups of antispasmodics 4.

Comparison with Other Treatments

• A study published in 2006 found that dicyclomine and hyoscyamine, two myorelaxants available in the United States, had not been proven effective in reducing abdominal pain in patients with IBS 5.
• Another study published in 2009 found that treatment options for IBS have increased in number in the past decade and clinicians should not be limited to using only fiber supplements and smooth muscle relaxants 6.
• The study suggested that treatment needs to be individualized and should focus on the predominant symptom, and that agents that modulate chloride channels and serotonin may be effective in treating IBS 6.

Adverse Effects

• The majority of adverse effects reported in the studies were related to the anti-cholinergic activity of the drug 3.
• Adverse events were not assessed as an outcome in the 2011 study 4.