Anticholinergics (antispasmodics) for irritable bowel syndrome

Examples

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Chemical Name

atropine sulfate

Brand Name	Chemical Name
Bentyl	dicyclomine hydrochloride

Brand Name	Chemical Name
Levsin	hyoscyamine sulfate

Brand Name	Chemical Name
Pro-Banthine	propantheline bromide

Brand Name	Chemical Name
Transderm-Scop skin patch	scopolamine

How It Works

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Antispasmodics relax the smooth muscles of the gut, helping to prevent or relieve painful cramping spasms in the intestines. These medications are taken 30 to 45 minutes before meals to help relieve cramping that occurs after eating.

Why It Is Used

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Antispasmodics are used to relieve cramps or spasms of the stomach, intestines, or bladder. They are the most commonly prescribed medications for treating irritable bowel syndrome (IBS).¹

IBS is a disorder of the intestines that causes abdominal pain or discomfort with constipation or diarrhea (and sometimes alternating episodes of both). Other common symptoms include bloating and passing mucus in the stools. The condition is more common in women than in men.

Do not use antispasmodics if you suffer from:

• Glaucoma.
• Urinary retention.

How Well It Works

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Several studies suggest that antispasmodics improve symptoms of IBS and reduce pain.² They can substantially reduce stomach and intestinal cramps and the urgency for a bowel movement after eating when taken 30 minutes before meals, especially meals that are expected to cause cramps.

Antispasmodics have no effect on diarrhea or constipation.

Side Effects

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Side effects may include drowsiness, dry mouth, blurred vision, or inability to urinate. Antispasmodics may make constipation—often a main symptom of IBS—worse.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

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Antispasmodics can be taken as needed for cramps, before meals that are expected to cause symptoms, or when symptoms would be inconvenient or bothersome.

If constipation is your main symptom, antispasmodics may not work for you. In some cases, use of antispasmodics can make constipation worse.

If you are pregnant, ask your doctor about taking antispasmodics. Some studies have suggested that some antispasmodics can increase the heartbeat of a fetus, and that some are related to birth defects, though they have not been proven to cause these defects.

If you suffer from glaucoma or urinary retention, do not use antispasmodics.

Complete the new medication information form (PDF) (What is a PDF document?) to help you understand this medication.

References

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Citations

1. Hasler WL (2002). The irritable bowel syndrome. Medical Clinics of North America, 86: 1525–1551.

2. Mertz HR (2003). Irritable bowel syndrome. New England Journal of Medicine, 349(22): 2136–2146.

Credits

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Author	Robin Parks, MS
Editor	Kathleen M. Ariss, MS
Associate Editor	Pat Truman
Primary Medical Reviewer	Kathleen Romito, MD - Family Medicine
Specialist Medical Reviewer	Arvydas D. Vanagunas, MD - Gastroenterology
Last Updated	June 15, 2006