Morphologic and ultrastructural effects of Maalox TC on human gastric and duodenal mucosa.

Prostaglandins (PGs) and aluminum-containing antacids (Al.AAs) are effective in preventing gastric and duodenal lesions induced by neutralizing agents. The efficacy of Al.AAs is thought to be due to neutralizing properties and to stimulation of endogenous PGs synthesis. Liquid Maalox has the same effect as cimetidine 400 mg on post-prandial duodenal acid load. In numerous prospective studies, Al.AAs have been shown to be as effective as cimetidine in the short-term treatment of duodenal ulcer (DU). Maalox TC at a dosage of 3 tablets b.i.d. provides an effective method for preventing DU relapse. Its effect is similar to that of nighttime cimetidine. Meta-analysis of prospective trials suggests that Al.AAs prevent stress ulcers more effectively than does cimetidine. It has been suggested that Al.AA acts by inducing surface epithelial cell disruption. Al-induced mucosal protection could be caused by a stimulated release of endogenous PGs, induced by Al microcrystal penetration of cells. In a recent study, we showed that small amounts of Al were absorbed by human gastric mucosa and accumulated in lysosomes; however, we did not observe any histological or ultrastructural lesions of the gastric mucosa. Prostaglandins (enprostil, misoprostol, and rioprostil) are as effective as cimetidine, but less effective than ranitidine, in healing DU. Enprostil and rioprostil have been shown to be as effective as ranitidine in treating gastric ulcer (GU). Moreover, enprostil inhibits postprandial gastrin release, whereas H-2-blockers increase gastrin levels. Coadministration of misoprostol with aspirin is highly effective in healing aspirin-induced gastroduodenal lesions. Moreover, cotreatment with misoprostol was associated with a marked decrease in GU in patients with osteoarthritis receiving NSAIDs chronically. Preliminary data suggesting that sucralfate and Al.AAs could efficiently prevent NSAIDs-induced gastric lesions remain to be confirmed.