Rioprostil and ranitidine in the prevention of duodenal ulcer relapse.

One hundred and ninety duodenal ulcer patients who had relief of pain and endoscopically proven ulcer healing after a short treatment period are allocated at random to double-blind maintenance treatment with a synthetic dehydroprostaglandin-E1, rioprostil, 300 micrograms, or ranitidine, 150 mg, at bedtime for 6 months. Patients are monitored every two months and examined by endoscopy after six months of treatment, or more often if warranted. The cumulative relapse rate in the rioprostil group at six months is 32% (25/78) vs. 28% (20/72) in the ranitidine group. This difference is not significant. The percentage of side effects observed is 17% in the rioprostil group vs. 5% in the ranitidine group, but discontinuation of treatment is observed with the same frequency in the two groups.

Treatment of duodenal ulcer with rioprostil: a randomized multicentre double-blind study.

The effectiveness of rioprostil, 300 micrograms b.d. is evaluated in evolutive duodenal ulcer in a double-blind study in five French and North African centres. A total of 115 patients are included in the study (57 in the rioprostil group and 58 in the placebo group). After a 4-week treatment period, a significantly higher endoscopic healing rate is observed in the rioprostil group (57%) compared with the placebo group (33%) (p less than 0.01). The mean time with abdominal pain is significantly lower in the rioprostil group (5.6 +/- 4.4 days) compared to the placebo group (12.7 +/- 5 days) (p less than 0.001). Clinical and biological tolerance is excellent. The only side effect is diarrhoea (3.5% in the rioprostil group). In only one case does diarrhoea necessitate cessation of treatment. Rioprostil, 300 micrograms b.d., is thus effective in the treatment of developing duodenal ulcer.

Pharmacokinetic interactions between theophylline and rioprostil.

The study is of double-blind crossover design. The effects of rioprostil, an analogue of prostaglandin E1, at a dose of 300 micrograms b.d., and placebo on the kinetic of slow-release theophylline are investigated. Eight healthy male volunteers participate in the study, each study period lasting for one week. During the first period, the doses of theophylline are altered in response to measured theophylline levels, 200 mg or 400 mg b.d. Regardless of placebo or rioprostil treatment, side effects appear before day 6 and are related specifically to theophylline administration. Blood samples are taken on days 4 and 5 to check steady-state plasma levels of theophylline and on days 6 and 7 to determine the main pharmacokinetic parameters. The same schedule is used for the second period of treatment. The achievement of steady-state concentration is verified. The mean pharmacokinetic parameters do not show a significant difference when slow-release theophylline is given alone or with rioprostil. These results are likely to be clinically relevant and, therefore, the theophylline dose should not be changed if rioprostil is prescribed at the same time as the theophylline.