Cimetidine, ranitidine, and pirenzepine in the treatment of duodenal ulcer: A six-month low-dose treatment period followed by a six-month observation period

One hundred twenty-one consecutive patients with healed duodenal ulcer (DU) entered a single-blind, randomized, one-year study. They were treated with either cimetidine 400 mg (41 patients), ranitidine 150 mg (40 patients), or pirenzepine 50 mg (41 patients) at bedtime for the first six months and had no treatment in the subsequent six-month observation period. The patients were well matched in common clinical and biochemical parameters. An upper gastrointestinal endoscopy was performed every three months in all asymptomatic subjects and at every symptomatic relapse. Statistics were calculated by chi-square test with Yate's correction, analysis of variance, and log rank test. There were 37 dropouts, 11 in the cimetidine group, 16 in the ranitidine group, and ten in the pirenzepine group. Raniditine-treated patients showed a better outcome than the other two groups after the first six months, although statistical significance was reached only versus the pirenzepine-treated group (P < 0.05). Overall results were not statistically different among the three treatment groups. The remission rate at the end of the study was 32.5 ± 8.8% for the cimeditine group, 45.6 ± 9.9% for the ranitidine group, and 30.2 ± 8.3% for the pirenzepine group. We conclude that, although ranitidine appeared to be more effective than cimetidine and pirenzepine in reducing DU relapse, none of the three drugs showed significant advantages over the others at six months after the end of drug therapy. Since long-term treatment does not appear to modify the natural history of DU, we suggest that maintenance therapy might be reserved only for high-risk patients.