Irritable bowel syndrome — dexloxiglumide
Irritable bowel syndrome (IBS) is a poorly understood condition, characterised by recurrent abdominal pain, which is often accompanied by alternating bouts of diarrhoea and constipation. It most commonly affects women between the ages of 20 and 40. No organic cause can be found by medical investigation techniques such as barium meal X-ray, but the colon is observed to contract and relax unusually frequently.
Several drugs have been developed to treat the symptoms of IBS, but it is still very difficult to control. Various classes of drug are being investigated, including muscarinic antagonists, ß3-adrenergic agonists and GI-selective calcium channel blockers; 5-HT3 receptor antagonists also show promise.1
A further approach is the use of dexloxiglumide, a selective, reversible cholecystokinin (CCK) inhibitor, being developed by US company Forest Laboratories under licence from Rotta Research Laboratorium of Italy. The hormone CCK is involved in the modulation of sensory and motor responses to distension in the intestinal tract. Abnormal distension may contribute to the symptoms of constipation, bloating and abdominal pain experienced by IBS sufferers.2
In a 12 week placebo controlled Phase II clinical trial in 405 patients with different types of IBS, 328 of whom were female, dexloxiglumide treatment proved more effective than placebo in moderating the symptoms.3 Statistically significant improvement was seen in female patients with constipation predominant IBS: 40% treated with dexloxiglumide had improved symptoms, compared with 22% who were given placebo.
Forest expects to initiate Phase III clinical trials in the near future. If these prove successful, then dexloxiglumide may be the answer for the many women who suffer from constipation predominant IBS.
