A comparative clinical trial of duodenal ulcer healing with two regimens of cimetidine: 800 mg once nightly and 400 mg twice daily.

The efficacy and safety of two dosage regimens of cimetidine were compared in a single-blind study of 50 adults with endoscopically proven duodenal ulcers. Patients were randomly allocated to receive 800 mg cimetidine taken once nightly or 400 mg cimetidine taken twice daily for 4 weeks. Following 4 weeks' treatment patients again underwent endoscopy and, if healing was incomplete, they received a further 4 weeks' treatment. At 4 weeks, healing occurred in 21/25 (84%) patients on the once-daily regimen and in 15/25 (60%) patients treated twice daily (P less than 0.05). Cumulative healing rates after 8 weeks' treatment were 92% and 96%, respectively. Symptomatic improvement was obtained to the same degree with both regimens. No adverse effects were recorded and laboratory values remained normal during both treatments. The results indicate that cimetidine given as one dose each night was superior to the twice-daily regimen.