Clinical characteristics of roxatidine acetate: a review.

Pharmacodynamic studies revealed that 150 mg of roxatidine acetate were optimal in suppressing gastric acid secretion, and that a single bedtime dose of 150 mg was more effective than a dose of 75 mg twice daily in terms of inhibiting nocturnal acid secretion. When administered orally as a capsule containing a granule formulation, the drug displayed modified-release properties, which led to a sustained suppression of gastric acid secretion. Clinical trials revealed that roxatidine acetate, 75 mg twice daily and 150 mg at night, was highly effective in healing duodenal and gastric ulcers and in reducing ulcer pain, over 4, 6, and 8 weeks of therapy. A steady reduction in diameter was observed in those ulcers not completely healed during therapy. The single bedtime dose regimen, while producing the same degree of healing as the divided daily dose during controlled clinical trials, may be of greater value in therapeutic use owing to improved patient compliance. In all efficacy criteria (cure, reduction in ulcer size, and pain relief) there was no significant difference between roxatidine acetate in a total daily dose of 150 mg, ranitidine in a total daily dose of 300 mg, and cimetidine in a total daily dose of 800 mg. Prevention of gastric and duodenal ulcer relapse was achieved by roxatidine acetate, 75 mg at night for 6 months, in about 70% of patients, as determined in open, pilot studies--a rate comparable to those reported for cimetidine and ranitidine. Roxatidine acetate shares with ranitidine an improved safety profile when compared with cimetidine. Human pharmacology studies and short-term and long-term clinical trials have all shown that roxatidine acetate is an exceptionally well tolerated compound, without the antiandrogenic activity and interference with hepatic drug metabolism which have characterized cimetidine treatment. A reason for the improved safety profile of roxatidine acetate may be its greater potency than cimetidine (six times less potent) and ranitidine (half as potent), so that lower doses of roxatidine acetate, representing a lower chemical load, are therapeutically effective. The novel structure of roxatidine acetate probably also underlies the improved safety of the compound.