Influence of clarithromycin dosage on pantoprazole combined triple therapy for eradication of Helicobacter pylori

Abstract

Background: Low-dose clarithromycin (250 mg b.d.) in combination with omeprazole and metronidazole has been recommended for the eradication of Helicobacter pylori. Whether the substitution of omeprazole by pantoprazole requires adjustment of the clarithromycin dose is not known. Aim: To directly compare the efficacy and tolerability of two different dosages of clarithromycin in combination with pantoprazole and metronidazole. Methods: One hundred and sixty-three patients with endoscopically confirmed gastritis, gastric or duodenal ulcers and positive H. pylori findings in the rapid urease test were randomized and treated for 7 days with pantoprazole (40 mg b.d.), metronidazole (500 mg b.d.) and clarithromycin using either a regimen of 500 mg b.d. (group PMC 500) or 250 mg b.d. (group PMC 250). Eradication success was determined no less than 4 weeks after concluding therapy using the 13C-urea breath test. Results: One-hundred and thirty-nine patients completed the study. Based on a per protocol analysis, successful eradication was documented in 63/70 patients (90.0%) in group PMC 500 and in 62/69 patients (89.9%) in group PMC 250. Based on the intention-to-treat analysis, eradication rates were 78.8% (group PMC 500) and 75.6% (group PMC 250). The incidence of adverse effects was significantly higher in patients receiving PMC 500 (50.0%) than in those receiving PMC 250 (25.4%). Conclusions: Triple therapy with pantoprazole, metronidazole and clarithromycin provides an efficient eradication regimen for H. pylori infection. A low dose of clarithromycin is equal to a higher dose in therapeutic efficacy and it offers the advantage of improved tolerance and lower cost.