Background:  Sequential regimens have been recently reported to be superior to the standard triple therapies in Helicobacter pylori eradication, but most of these studies were performed in Europe and data from developing countries are lacking. So we designed a study to compare a sequential regimen with a bismuth‐based quadruple therapy that contains a short course of furazolidone, in Iran.

Methods:  Two hundred and ninety‐six patients with duodenal ulcer and naïve H. pylori infection were randomized into two groups: 148 patients received (PAB‐F) pantoprazole (40 mg‐bid), amoxicillin (1 g‐bid), and bismuth subcitrate (240 mg‐bid) for 2 weeks and furazolidone (200 mg‐bid) just during the first week. And 148 patients received (PA‐CT) pantoprazole (40 mg‐bid) for 10 days, amoxicillin (1 g‐bid) for the first 5 days, and clarithromycin (500 mg‐bid) plus tinidazole (500 mg‐bid) just during the second 5 days. C¹⁴‐urea breath test was performed 8 weeks after the treatment.

Results:  Two hundred and sixty‐one patients completed the study (137 patients in the PA‐CT and 124 in the PAB‐F group). The results were not statistically different between the two groups in the eradication rates and the severity of side effects. The intention to treat eradication rate was 80.4% in the PAB‐F group and 83.7% in the PA‐CT group. Per‐protocol eradication rates were 88.7% and 89.1%, respectively.

Conclusion:  Because the two regimens showed acceptable and similar abilities in H. pylori eradication and because of much higher cost of clarithromycin in Iran, the furazolidone containing regimen seems to be superior. Further modifications of sequential therapies are needed to make them ideal regimens in developing countries.