Antisecretory and mucosal protective actions of misoprostol. Potential role in the treatment of peptic ulcer disease.

Misoprostol, a synthetic methyl ester analogue of prostaglandin E1, inhibits basal, nocturnal, and stimulated gastric acid secretion. In doses of 400 to 1,200 micrograms daily, misoprostol accelerates the healing of duodenal and gastric ulcers in humans. In addition to its antisecretory actions, misoprostol has gastroduodenal mucosal protective (cytoprotective) effects in animals and in humans. In humans, these cytoprotective actions have been demonstrated in acid-dependent studies using non-antisecretory doses and in acid-independent studies using antisecretory doses. Patients with peptic ulcer disease may have a relative deficiency of mucosal prostaglandin synthesis as compared with nonulcer control subjects. In addition, patients who consume nonsteroidal anti-inflammatory drugs and those who are cigarette smokers may also have depressed gastric mucosal prostaglandin synthesis. There is some evidence that misoprostol reverses the deleterious effect of smoking on duodenal ulcer healing and that it is effective in treating and preventing mucosal damage induced by nonsteroidal anti-inflammatory drugs and alcohol.