N-Acetylcysteine as adjunct on the standard treatment for Helicobacter pylori infection: a meta-analysis

Background: Treatment of dyspepsia, gastritis, gastroduodenal ulcers and malignancies has evolved since the identification of the causative role of Helicobacter pylori infection in these conditions.   Currently, the use of triple therapy with Proton pump inhibitors plus two antibiotics and Quadruple therapy with addition of Bismuth citrate have become the standard treatment. However, in the recent years, there is a reported 10-20% failure rate in the treatment of H pylori infection and this is due to the resistance developed by H pylori against current treatment. Studies are now  ongoing in order to determine additional therapies that could be used to decrease this rate of resistance to antibiotic therapy. N-Acetylcysteine is a mucolytic that could act on H pylori biofilm, which was implicated as the cause for such resistance to standard H pylori treatment. This meta analysis aims to determine whether the use of N-Acetylcysteine as adjuvant to standard H pylori treatment would produce significant increase in H pylori eradication. 

Methods: A systematic search of relevant studies was done through MEDLINE, Cochrane Library, ClinicalTrials.gov and Google free text. Studies considered were randomized controlled clinical trials that had an experimental group receiving N-acetylcysteine as adjunct to standard  therapy for Helicobacter pylori infection and a control group receiving standard therapy alone. The authors independently examined each of the retrieved studies. The primary outcome considered was the eradication of H pylori infection confirmed by either Giemsa staining or rapid urease test documented after the completion of therapy.

Results: Four trials were included in the analysis. The four trials altogether enrolled a total of 357 patients, 177 of which were randomly assigned to the experimental group (N-acetylcysteine + standard H. pylori regimen) and 180 subjects randomly assigned to the control group. These 4 studies were analyzed using a fixed effect analysis, which did not show any significant effect (OR 0.82; 95% CI 0.52 to 1.30). However the studies showed moderate heterogeneity (Chi² = 5.46, df = 3 (P = 0.14); I² = 45%). Random effect analysis was utilized and showed similar results. A subgroup analysis was subsequently done which did not show a significant effect as well (OR 1.02; 95% CI 0.61 to 1.69).

Conclusion: Analysis of the studies revealed that the eradication of H pylori in the experimental groups receiving N-acetylcysteine is higher than the standard treatment group. However, these results did not show statistical significance hence the authors recommend a larger trial involving more subjects in order obtain  more conclusive results.