Constipation Relief

The drug bisacodyl is effective against chronic constipation and improves patients’ quality of life, according to a large study published by Michael Kamm et al. in the July issue of Clinical Gastroenterology and Hepatology.

Constipation affects 12% to 19% of Americans; its prevalence increases with age and it affects women more than men. It has a major impact on quality of life—Americans spend more than $700 million annually on over-the-counter laxatives.

Bisacodyl, a diphenylmethane derivative, has been available as a laxative since 1952, but there have been insufficient data from high-quality controlled trials on its efficacy, hindering recommendations for its use in patients with chronic constipation.

Kamm et al. performed a randomized, double-blind, placebo-controlled study across 27 medical centers in the United Kingdom to assess the efficacy, safety and changes to quality of life in patients with chronic constipation, based on the Rome III diagnostic criteria. Patients were given either 10 mg bisacodyl (n = 247) or a placebo (n = 121), once daily for 4 weeks, and results were recorded in an eDiary, as recommended by the Food and Drug Administration.

Bisacodyl rapidly the increase frequency of complete bowel actions and had a sustained effect; the percentage of patients who had at least 1 stool per day increased 17-fold in the group given bisacodyl. The drug also reduced their constipation-associated symptoms and improved disease-related quality of life (see below figure). The difference between groups was greater than in trials of other drugs for constipation.

Improved quality of life among patients given bisacodyl for constipation, compared with those given placebo.

Bisacodyl is usually effective within 6 to 12 hours of oral administration and within about 20 minutes of rectal administration. It is converted by intestinal deacetylase enzymes into an active metabolite, bis-(p-hydroxyphenyl)-pyridyl-2-methane (BHPM), which has antiabsorptive-secretory effect and a direct prokinetic effect. Half of the patients in the bisacodyl group had their first spontaneous bowel movement within 12 hours after taking the drug.

Kamm et al. found that patients could adjust the dose to minimize side effects (diarrhea and headache) while maintaining efficacy.

These are the first published data to demonstrate the impact of bisacodyl on patients’ quality of life; the authors believe that this drug and sodium picosulfate are now the only over-the-counter laxatives shown to do so. Sodium picosulfate is also converted, in the gastrointestinal tract, to BHPM. Kamm et al. conclude that laxatives from the diphenylmethane group are the most effective approach for constipation.

More Information on Chronic Constipation:

• NIDDK Website on Constipation

Read the article online.
Kamm MA, Mueller-Lissner S, Wald A, et al. Oral bisacodyl is effective and well-tolerated in patients with chronic constipation. Clin Gastroenterol and Hepatol 2011;9:577–583.