Review of tegaserod in the treatment of irritable bowel syndrome

Tegaserod is a drug in a new class of compounds called aminoguanidine indoles and is structurally similar to serotonin (5-HT) with modifications that make the drug selective for the 5-HT(4) receptor. Tegaserod has a stimulatory effect on gastrointestinal (GI) motility that has been demonstrated in animal studies and in healthy adults. Tegaserod also increases GI secretion and reduces rectal sensitivity. Tegaserod is currently approved by the FDA for the treatment of women with constipation-predominant irritable bowel syndrome (C-IBS). Eight large Phase III clinical trials involving > 5000 IBS patients support the clinical efficacy of tegaserod in this group of patients. Patients who were treated with tegaserod had an overall improvement in IBS symptoms (Subject's Assessment of Global Relief) as well as in secondary end points, such as abdominal pain and discomfort, stool consistency, change in bowel movements and relief of bloating. Tegaserod was well-tolerated. The most common adverse reaction in clinical trials was diarrhoea, which was usually temporary and mild, although severe diarrhoea requiring hospitalisation has been rarely (< 1%) reported.