The investigation of novel compounds for the treatment of irritable bowel syndrome remains a challenging area of R&D for both the biotechnology and pharmaceutical industries. The problem stems from the lack of understanding of the etiology and pathophysiology of this common functional gastrointestinal (gastrointestinal) disorder. Because the majority of current therapies for irritable bowel syndrome address abnormal motility more effectively than they do pain, most irritable bowel syndrome drug development in recent years has focused on therapies for visceral hypersensitivity. This approach has proved very difficult because the exact pathways involved in visceral sensitivity in irritable bowel syndrome have not been fully characterized.
The agents at the most advanced stages of development for irritable bowel syndrome are in the following drug classes: 5-HT receptor modulators, tachykinin receptor antagonists, cholecystokinin (CCK) A receptor antagonists, opioid receptor modulators, corticotropin-releasing factor (CRF) receptor antagonists, and chloride-channel activators. In preclinical development are agents that target somatostatin receptors, antagonize the actions of motilin, modulate ion-channel activity, and inhibit the activity of the transcription factor NFkB. These novel approaches have the potential to combat both abdominal pain and motility abnormalities in irritable bowel syndrome. However, further discussion of these early-stage compounds is not within the scope of this section, which focuses on compounds in clinical development.