Histamine H2 antagonists for functional dyspepsia: A protocol for a systematic review and meta-analysis

BACKGROUND: Functional dyspepsia (FD) is a prevalent gastrointestinal disorder. Histamine H(2) antagonists (H(2)RAs) are the pharmacological treatment option for FD, but no potent evidence has been found for the efficacy of these drugs in the condition. Therefore, this systematic review protocol aims to examine the efficacy and safety of H(2)RAs in the treatment of FD. METHODS: We will perform a systematic search in the following electronic databases: the Cochrane Central Register of Controlled Trials (to October 2019), MEDLINE (OvidSP; to October 2019), EMBASE (OvidSP; to October 2019). Only randomized clinical trials (RCTs) comparing any H(2)RA with placebo for the treatment of FD will be included. The primary outcome will be an improvement in global symptoms of dyspepsia. Study selection, data extraction, and study quality will be performed by 2 independent reviewers. Dichotomous data will be presented as a risk ratio (RR) with 95% confidence intervals (CI), and continuous data as mean difference (MD) or standardized MD (SMD) with 95% CI. RevMan v.5.3 software will be used for all statistical analyses. RESULTS: This study will provide a high-quality synthesis to examine the role of H(2)RAs in FD as reflected by the improvement of global symptoms of dyspepsia, quality of life scores, and adverse events. CONCLUSION: This systematic review will provide updated evidence to judge whether H(2)RAs are of benefit in FD.