Nifedipine reduces the colonic motor response to eating in patients with the irritable colon syndrome.

Patients with the irritable colon syndrome have an exaggerated and/or prolonged colonic motor response to eating. This is believed to be the cause of their postprandial complaints. Since the flux of calcium ions across cell membranes plays a major role in the contractions of the gastrointestinal smooth muscle, we investigated the effect of nifedipine, a calcium channel blocker, on the gastrocolonic response in nine patients with the irritable colon syndrome. Colonic myoelectric and contractile activity was recorded during fasting and after a 1000-cal mixed meal, either with or without nifedipine (20 mg sublingually) administration. Nifedipine reduced the postprandial increase of both spike potential activity and motility index. This effect of acute administration of the drug provides rational support to test nifedipine in clinical trials as a possible means for treating the irritable colon syndrome.