Dose validation and study design criteria in current cimetidine studies.

A large dose validation study compared cimetidine 800 mg at bedtime, a dose known to provide maximum acid suppression through the night, with placebo, cimetidine 400 mg, and 1,600 mg in the treatment of acute duodenal ulcer. The study was also designed to assess the effects of smoking and ulcer size on duodenal ulcer healing. Results of the study indicated that both smoking and ulcer size negatively correlated with ulcer healing. Cimetidine 800 mg (75%) was superior to placebo (45%) and cimetidine 400 mg (60%) (P less than 0.05) in terms of ulcer healing. There was no statistically significant difference between cimetidine 800 mg and 1,600 mg (81%). Up to 80% of the patients treated with cimetidine 800 mg had some degree of pain relief after the first dose. Cimetidine 800 mg was superior to placebo with respect to both daytime and nighttime pain relief at all assessment points and was superior to 400 mg during the first week. There was no difference in pain relief between 800 mg and 1,600 mg at any assessment period. It was clear that cimetidine 800 mg is the most appropriate dosage in the acute therapy of duodenal ulcer, combining optimal healing with maximum pain relief.