Inhibition of gastric secretion in man by rioprostil, a new synthetic methyl prostaglandin E1.

The effect of rioprostil, a new synthetic prostaglandin (PG) E1 (2-decarboxy-2-hydroxymethyl-15-deoxy-16RS-hydroxy-16-methyl PGE1), on basal and pentagastrin stimulated gastric secretion was investigated in a placebo controlled double-blind crossover study in 6 healthy male volunteers. Rioprostil reduced both basal and stimulated gastric secretory volume, as well as acid and pepsin secretion. At doses of 300 and 600 micrograms rioprostil reduced basal acid secretion by 54 and 88% and basal pepsin secretion by 86 and 68%, respectively. The two doses of rioprostil reduced stimulated acid secretion by 44 and 59% and stimulated pepsin secretion by 40 and 67%, respectively. Loose stools were observed in three subjects, other side-effects were minor and not different as compared to placebo. It is concluded that rioprostil is a potent inhibitor of both acid and pepsin secretion in man.