News Release

Photo: For a photo of Drossman, click on http://www.unc.edu/news/pics/drossman.jpg

Lubiprostone relieves abdominal pain associated with constipation

CHAPEL HILL – A drug that provides significant relief to people suffering from infrequent and difficult passage of stool also helps patients suffering from abdominal pain associated with constipation, two studies led by a University of North Carolina at Chapel Hill researcher have found.

People in the studies who took lubiprostone (Amitiza) were almost twice as likely than people who took a placebo to report moderate or significant relief from abdominal discomfort or pain and a lessening of constipation severity, said lead investigator Douglas A. Drossman, M.D., co-director of the UNC Center for Functional GI and Motility Disorders and a professor in the UNC School of Medicine.

“This medication, having previously shown to help constipation alone, appears also to have benefit for abdominal pain that occurs with constipation,” Drossman said.

Drossman will present the findings May 22 at the annual Digestive Disease Week meeting in Washington, D.C. Funding for the Phase III clinical trials was provided by Takeda Pharmaceuticals and Sucampo Pharmaceuticals, which make and market the drug. Drossman led the studies, which took place at 65 sites.

The U.S. Food and Drug Administration approved lubiprostone in January 2006 for the treatment of chronic idiopathic constipation cases not caused by other diseases or by use of medications. According to the FDA, chronic idiopathic constipation is generally defined as infrequent and difficult passage of stool and is one of the most common disorders suffered by Americans. In addition the new studies show benefit for irritable bowel syndrome with constipation, defined as abdominal pain or discomfort associated with the constipation. Both conditions affect women more often than men and can be associated with bloating, straining and hard stools. IBS tends to occur in younger populations while constipation affects all ages and is quite common in older patients after the age of 65.

In the two studies, 1,171 people diagnosed with irritable bowel syndrome with chronic idiopathic constipation received either lubiprostone or a placebo in soft gelatin capsules for 12 weeks. Each week study participants were asked to answer the question, “How would you rate your relief of IBS symptoms (abdominal discomfort/pain, bowel habits, and other IBS symptoms) over the past week compared to how you felt before you entered the study?”

Participants gave their answers using a seven-point scale, and those who used the two highest scale points were considered “responders.” Those who reported at least moderate relief four out of four weeks or significant relief two out of four weeks were considered monthly responders. To qualify as an overall responder, participants had to be a monthly responder for at least two out of three months.

Among those who received lubiprostone, 17.9 percent achieved overall response compared to only 10.1 percent of those who received placebo. In addition, both studies showed statistically significant improvement in the lubiprostone group on measures such as abdominal discomfort/pain, stool consistency, straining, constipation severity and quality of life. Lubiprostone was also well-tolerated by study participants and had a low rate of negative side effects.

Results from the two new studies “further demonstrate the efficacy and tolerability of lubiprostone for treatment of adults with chronic constipation associated with irritable bowel syndrome,” Drossman said.

Drossman’s co-authors were W.D. Chey of the University of Michigan Health System and R. Panas, C. Scott and R. Ueno, all of Sucampo Pharmaceuticals, the maker of Amitiza.

UNC Center for Functional GI and Motility Disorders Web site: http://www.med.unc.edu/medicine/fgidc/

Note: Drossman can be reached at (919) 966-0142 or drossman@med.unc.edu

School of Medicine contact: Stephanie Crayton, (919) 966-2860 or scrayton@unch.unc.edu
News Services contact: Becky Oskin, (919) 962-8596 or becky_oskin@unc.edu