Meta-analysis:: the efficacy, adverse events, and adherence related to first-line anti-Helicobacter pylori quadruple therapies

Background: Owing to rising drug-resistant Helicobacter pylori infections, currently recommended proton-pump inhibitor-based triple therapies are losing their efficacy, and regimens efficacious in the presence of drug resistance are needed. Aims: To summarize the efficacy, safety and adherence of first-line quadruple H. pylori therapies in adults. Methods: Meta-regression models identified factors explaining variation in the efficacy of first-line quadruple therapies from 145 treatment arms. Estimates of average efficacy were calculated within homogeneous groups. Results: Quadruple therapy containing a gastric acid inhibitor. bismuth, metronidazole and tetracycline was enhanced when omeprazole was included, treatment duration lasted 10-14 days, and when therapy took place in the Netherlands, Hong Kong and Australia. Treatment efficacy decreased as the prevalence of metronidazole resistance increased. Even in areas with a high prevalence of metronidazole resistance, this quadruple regimen eradicated more than 85% of H. pylori infections when it contained omeprazole and was given for 10-14 days. Furthermore, in the presence of clarithromycin resistance, this quadruple regimen eradicated 90-100% of H. pylori infections, while the currently recommended triple therapy containing clarithromycin, amoxicillin and a proton-pump inhibitor eradicated only 25-61% (P < 0.001). Adherence and adverse events for quadruple therapy were similar to currently recommended triple therapies. Conclusions: Guidelines should include quadruple therapy with a proton-pump inhibitor, a bismuth compound, metronidazole and tetracycline among recommended first-line anti-H. pylori therapies.