Prostaglandins and peptic ulcer disease: nocturnal administration of rioprostil vs ranitidine in duodenal ulcer healing.

Hypochlorhydria induced by potent antisecretory drugs is followed by a marked elevation of serum gastrin levels which leads to changes in ECL cell density in rats. "Soft" antiulcer drugs like prostaglandins do not increase gastrin levels. Their use in peptic ulcer disease seems to be mainly limited by a relatively high incidence of diarrhea and abdominal cramps. Rioprostil is a new prostaglandin E1 analogue. We compared the potency and duration of action of rioprosil 600 micrograms nocte with 300 micrograms bid on human gastric secretion in a placebo-controlled double-blind study. We further evaluated the clinical effectiveness of rioprostil 600 micrograms nocte in the acute treatment of duodenal ulcer. Nocturnal gastric acidity (24:00 to 08:00) was inhibited from 54.5 +/- 1.7 mmol H+/L (placebo experiments; n =9) to 26.7 +/- 3.5 mmol H+/L (52%) by rioprostil 300 micrograms bid (p less than 0.05) and to 14.4 +/- 3.8 mmol H+/L (74%) by rioprostil 600 micrograms nocte (p less than 0.05). During the daytime (09:00 to 18:00), H+ activity was reduced by 33% and 15% respectively (n.s.). Two hundred and three patients with endoscopically proven duodenal ulcers were randomly allocated to treatment with either rioprostil 600 micrograms nocte or ranitidine 300 mg nocte for 4 weeks in a prospective double-blind study. The two groups were similar. After 2 and 4 weeks treatment respectively, about 55% and 85% of patients healed on rioprostil 600 micrograms nocte and 55% and 90% on ranitidine 300 mg nocte. There were no differences between the treatment groups in ulcer pain relief.(ABSTRACT TRUNCATED AT 250 WORDS)