Efficacy of a novel eradication treatment with ranitidine, trichopol and jozamycin was compared to that of the standard three-component therapy and monotherapy with ranitidine in 76 patients with exacerbation of gastric and duodenal ulcer. Therapeutic monitoring of ranitidine was performed. In relation to healing of ulcer defect and eradication of Helicobacter pylori, jozamycin is not less effective and more safe than standard three-component therapy. Interaction of the scheme components increases plasma concentration of ranitidine especially in patients with concomitant hepatic and renal diseases.