Placebo controlled studies with ranitidine in duodenal ulcer

171 duodenal ulcer patients were treated for four weeks with either ranitidine or placebo under double-blind conditions. 40 patients (monocentre study) received ranitidine (40 mg), or placebo t.d.s. with meals and 80 mg at bedtime. 131 patients (multicentre study) received ranitidine (150 mg), or placebo b.d. In the monocentre study endoscopy after 4 weeks of treatment showed complete healing in 83.3% of the ranitidine patients and 30.4% of those on placebo (P less than 0.01%). In the multicentre study the healing percentages were 79.4% and 30.4%, respectively (P less than 0.001). In both trials pain and antacid consumption decreased in patients taking ranitidine more than in patients on placebo. After 4 weeks in the double blind studies 13 of the 15 patients with unhealed ulcer in the monocentre study and 51 of 54 patients in the multicentre study received open treatment with ranitidine for another 4 week period. The overall healing percentages by the 8th week of treatment with ranitidine were 94.4% and 93.6% respectively. No serious side effects, or haematological changes were observed during the treatment with ranitidine.