Abstract
Possible mechanisms of drug interactions with H2-antagonists are outlined. The mode of action of roxatidine acetate on hepatic microsomal enzymes is contrasted with those of cimetidine and ranitidine, and their differing structure-activity relationships are discussed. In the light of the mechanisms of drug interactions with H2-antagonists, clinical studies with roxatidine acetate are contrasted with published interaction data of cimetidine and ranitidine. The therapeutic consequences of these data are considered.