Drug Relieves MS Constipation — at a Price

ORLANDO — Treatment of constipation in multiple sclerosis (MS) patients with lubiprostone increased spontaneous bowel movements but also appeared to induce diarrhea, according to a small trial reported here.

In a 21-patient randomized, double-blind, placebo-controlled study lasting 3 weeks, the rate of spontaneous bowel movements more than tripled in the 11 assigned to lubiprostone (P=0.04), but only when initial effects in three patients who discontinued early were assumed to have continued had they stayed in the trial, reported Cynthia Irish, RN, and colleagues at the University of Rochester in N.Y.

In analyses that handled the dropouts differently — such as excluding them altogether or assuming that they had no spontaneous bowel movements after leaving the study — lubiprostone showed only a weak advantage over placebo, according to the researchers’ report at the joint meeting of the Consortium of Multiple Sclerosis Centers and the Americas Committee for Treatment and Research in Multiple Sclerosis.

The adverse events driving the three patients from the trial appeared to be diarrhea, suggesting that lubiprostone may have been too effective in these individuals.

Results from the analyses “would lead one to believe that lubiprostone was effective in increasing the number of spontaneous bowel movements at the price of an increase in diarrheic events,” Irish and colleagues concluded.

Constipation is one of the many less-publicized effects of MS, affecting more than 40% of patients in one study. Whether conventional treatments for the condition are effective in MS patients remains unclear.

Lubiprostone (Amitiza) is FDA-approved for relieving chronic idiopathic constipation and opioid-induced constipation in adults as well as constipation-predominant irritable bowel syndrome (IBS) in women. The American College of Gastroenterology has recommended the drug for constipation associated with IBS.

However, as Irish and colleagues pointed out, the drug has not been evaluated for constipation arising from neurological disorders.

In their study, they recruited a total of 40 MS patients reporting chronic constipation. Of these, 19 were excluded, most because they had more than four spontaneous bowel movements during a 2-week washout period, when patients’ previous constipation medications were stopped. Patients then received either placebo or 24 mcg of lubiprostone twice daily for 3 weeks.

Patients included in the trial represented a mix of MS types, including both relapsing and progressive forms. Their mean age was 45 and the mean duration of their MS was 14.5 years. The mean expanded disability status scale (EDSS) score was 5.2.

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