Protective effect of rioprostil on indomethacin-induced lesions of gastric and duodenal mucosa in healthy volunteers.

The protective effect of rioprostil against gastroduodenal mucosal lesions induced by indomethacin is investigated in a double-blind controlled trial on 36 healthy adult volunteers, divided into three groups. All the volunteers are treated with indomethacin, 50 mg t.d.s. during a period of 5 days. The first group is treated with placebo, the second with rioprostil, 300 micrograms, and the third with rioprostil, 600 micrograms. Endoscopies are performed before and after treatment. Blood samples for high performance liquid chromatography determination of indomethacin plasma concentrations are taken on the 6th day, before the last dose of indomethacin is administered, and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12 and 24 h after the last dose of indomethacin. It is found that in both doses rioprostil exerts a protective effect against indomethacin-induced lesions, reducing the appearance rate of erosions from 67% to 17% statistically significant in the 600 micrograms group. The bioavailability of indomethacin in the three groups does not differ significantly.