Jim Kling

October 23, 2012

LAS VEGAS, Nevada — Low-dose tricyclic antidepressant therapy is effective in treating moderately severe functional symptoms in patients with inflammatory bowel disease (IBD) who are not experiencing overt disease, according to a study presented here at the American College of Gastroenterology 2012 Annual Scientific Meeting and Postgraduate Course.

About 15% of adults suffer from irritable bowel syndrome (IBS). Antidepressants, including tricyclic antidepressants, are commonly used to treat IBS. IBD patients who are in remission or who have only mild disease activity present primarily with functional symptoms that are similar to what is seen in IBS patients.

"In our clinical practice, a lot of times our IBD patients on maximum immune suppression complain of continued symptoms, such as cramping, or more frequent bowel movements than they would like. Clinically, we were using antidepressants to treat these symptoms, specifically tricyclics, which we [often] use for irritable bowel syndrome," Heba Iskandar, MD, a gastroenterology fellow at Washington University in St. Louis, Missouri, who presented the research, told Medscape Medical News.

To assess whether tricyclic antidepressants can successfully treat IBS-like symptoms in IBD patients, the researchers conducted a retrospective open-label study in an academic gastroenterology practice from 2000 to 2011. They compared 81 IBD patients (56 female) in clinical remission or with mild inflammation and persistent gastrointestinal (GI) symptoms (mean age, 41.3 years) with 77 symptomatic IBS patients (60 female) who did not have IBD (mean age, 46.2 years)

The researchers used a 4-point Likert scale to assess symptom severity and improvement.

In the IBD group, 58 patients had Crohn's disease and 23 had ulcerative colitis with no evidence of disease activity. Patients continued maintenance IBD therapy; 22.2% received 5-aminosalicylic acid, 16.1% received biologics, 28.4% received immunomodulators, and 27.0% received no active IBD therapy.

Surgical resection had been performed on 48.1% of the IBD patients; 43% were in remission and 57% had mild disease activity.

The incidence of abdominal pain and diarrhea was similar in the IBD and IBS groups.

The IBD and IBS groups had moderate to severe baseline symptom scores (2.06 vs 2.12; = .15). After antidepressant therapy, there were slight to moderate improvements in the IBD and IBS groups (1.46 vs 1.30; = .20). Improvement was at least moderate in 48 of 81 patients in the IBD group and in 35 of 77 patients in the IBS group (59.3% vs 46.0%; P = .09).

At the first visit, patients with ulcerative colitis had a better response than those with Crohn's disease (1.86 vs 1.26; = .003).

Overall predictors of response to tricyclic antidepressants included ulcerative colitis subtype (odds ratio [OR], 4.7; 95% confidence interval [CI], 1.4 to 16.3; = .01), the presence of pain (OR, 0.3; 95% CI, 0.1 to 0.98; = .048), and the presence of a comorbid functional diagnosis (OR, 0.5; 95% CI, 0.2 to 0.9; = .035).

Dr. Iskandar summed up by saying that "IBD and IBS patients responded similarly, and ulcerative colitis patients had a higher mean response."

The study is hypothesis-generating and needs to be followed by a prospective study, according to Brian Lacy, MD, PhD, professor of medicine and chief of gastroenterology at the Dartmouth-Hitchcock Medical Center in Lebanon, New Hampshire, who attended the session.

"What's exciting is that there is this whole emerging field recognizing an overlap between IBD and IBS. We're now starting to translate from functional bowel disorders to the IBD field.... [This study] is a great first step," Dr. Lacy told Medscape Medical News.

Dr. Iskandar and Dr. Lacy have disclosed no relevant financial relationships.

American College of Gastroenterology (ACG) 2012 Annual Scientific Meeting and Postgraduate Course: Abstract P1010. Presented October 22, 2012.