Antispasmodic Medications for IBS

Medications. Credit: Photo: Muskateer/Getty Images

At any given time, about 10 to 20 percent of people may experience the symptoms of Irritable bowel syndrome (IBS), a functional gastrointestinal disorder that causes abdominal pain and a change in bowel habits. Researchers have yet to zero in on what causes IBS, and treatment is aimed at relieving the symptoms of this bothersome but rarely dangerous disorder.

Among the various medications physicians may prescribe to help with IBS symptoms, antispasmodics have been found to reduce one of the more vexing symptoms of irritable bowel syndrome -- abdominal pain.

It is thought that this pain comes from spasms in the smooth muscle of the intestinal system. Antispasmodics aim to relax and improve the functioning of these muscles, therefore providing relief from symptoms.

In general, studies have shown that antispasmodics are moderately effective in providing short-term relief of IBS pain. There is not a lot of research as to the long-term effectiveness of antispasmodics.

The positive effect of antispasmodics may be particularly beneficial to individuals whose abdominal pain symptoms are worsened when they have just eaten. Because of this, antispasmodics are usually best taken as needed 30 to 60 minutes prior to meals.

The most common antispasmodics are anticholinergic medications and peppermint oil.

Anticholinergic Medications

Prescription antispasmodics are typically of a class of medications called anticholinergics. Anticholinergics act upon the neurotransmitter acetylcholine.

Reducing the effect of acetylcholine in the intestines results in a decrease in muscle spasms and a reduction in the secretion of mucus. Unfortunately, this anticholinergic effect also affects other systems within the body, thus resulting in unpleasant side effects:

  • Blurred vision
  • Constipation
  • Decreased urination
  • Dizziness
  • Dry mouth

Due to the risk of constipation, antispasmodics may be better for the treatment of diarrhea-predominant IBS (IBS-D), rather than constipation-predominant IBS (IBS-C).

The most commonly prescribed antispasmodics in the U.S. are:

  • Dicyclomine (Bentyl)
  • Hyoscyamine, hyoscamine (Anaspaz, Cystospaz, Levbid, Levsin)
  • Hyoscine Butylbromide (Buscopan

Peppermint Oil

Peppermint is an over-the-counter supplement. The menthol in peppermint oil is thought to have a relaxing effect on smooth muscle, thus reducing gut spasms. There is moderate research support regarding peppermint oil's effectiveness in easing IBS symptoms.

For some, peppermint oil may result in heartburn -- this may be reduced through the use of enteric coated capsules.

Be sure to consult your physician before taking peppermint oil or any other over-the-counter supplements.

Dietary Changes

In addition to medications to help relieve symptoms, changes in diet can help manage the disease very well for some patients. Recommended dietary measures include:

  • Supplementing with fiber, which can improve symptoms of both constipation and diarrhea

  • Increasing water intake for patients with constipation-predominant IBS

  • Avoiding caffeine to help ease anxiety and symptom exacerbation

  • Avoiding legumes to decrease abdominal bloating

  • Limiting foods containing lactose, fructose, and/or FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) for patients with these sensitivities

  • Taking a daily probiotic

Sources:

Ford, A., et.al. "American College of Gastroenterology Monograph on the Management of Irritable Bowel Syndrome and Chronic Idiopathic Constipation" American Journal of Gastroenterology 2014 109:S2-S26.

Ford, et.al. "Effect of fibre, antispasmodics, and peppermint oil in the treatment of irritable bowel syndrome: systematic review and meta-analysis." BMJ 2008 337:a2313.

Lacy, B., Weiser, K. & Lee, R. The treatment of irritable bowel syndrome. Therapeutic Advances in Gastroenterology 2009 2:221 - 238.

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