Does treatment with cimetidine extended beyond initial healing of duodenal ulcer reduce the subsequent relapse rate?

Cimetidine 1 g daily is often continued for a fixed period beyond the time of healing of duodenal ulcer on the assumption that it might reduce the subsequent relapse rate. To test this, 194 patients whose ulcers had healed after one month of cimetidine 1 g daily were allocated at random to three groups for further treatment with cimetidine 1 g daily for two months (n = 63) or five months (n = 66) or placebo (n = 65). Thereafter all patients received placebo. Endoscopy was done routinely every three months, or earlier if symptoms recurred. During follow-up in the placebo phase, which lasted for up to 25 months, the estimated total proportions of patients in the three groups with symptomatic recurrences of ulcer were 80%, 90%, and 77%, respectively; the corresponding proportions with silent plus symptomatic relapses were 92%, 90%, and 100%. The relapse rates were also similar in all three groups. Statistical analysis showed a significant variation in relapse rate but the differences were regarded as clinically unimportant. These findings show that full-dose cimetidine continued for several months beyond the time of healing of duodenal ulcer dose not decrease the risk of subsequent relapse.