Background: Omeprazole plus amoxicillin may cure Helicobacter pylori infection. However, the published results vary rather widely, and the factors influencing the treatment success remain unclear.
Methods: Four hundred and twenty-three H. pylori-positive patients were treated with 1- or 2-week regimens comprising 40 mg or 80 mg omeprazole and amoxicillin in 11 prospective protocols. A complete set of data was available for 405 patients (ulcer disease, n = 383; dyspepsia, n = 22) and was submitted to uni- and multi-variate statistical analyses to elucidate the factors affecting the cure rates of the infection; 18 patients were lost to follow-up.
Results: The overall proportion of H. pylori cure was 76%. Insufficient compliance (p < 0.001), a short duration of treatment (p < 0.001), smoking (p = 0.003), and omeprazole pretreatment (p = 0.041) were the significant independent factors predicting treatment failure, whereas advanced age (p = 0.002), high scores of grade and of activity of gastritis (p = 0.035 and p = 0.019, respectively), and gastric ulcer disease (p = 0.058) were independent factors predicting treatment success.
Conclusions: Several patient- and therapy-related factors diminish or increase the rate of H. pylori cure obtained by omeprazole/amoxicillin. These should be considered in future studies comparing different treatment regimens for curing H. pylori infection and also when designing treatment regimens applicable for routine clinical practice.