Functional dyspepsia (FD or non-ulcer dyspepsia) is defined as continuous or frequently recurring epigastric pain or discomfort for which no organic cause can be found. Acid suppressive therapy, including proton pump inhibitors (PPIs), has been proposed as a therapeutic option in FD, but its efficacy remains controversial. While PPIs are generally considered safe and well tolerated, they have been associated with adverse events, especially in the long term. For this reason, decisions on whether to initiate or continue PPI therapy should be made based on an appropriate clinical indication. Therefore, we conducted a systematic review to evaluate whether PPI therapy provides symptomatic relief in FD.
To determine the efficacy of proton pump inhibitors in the improvement of global symptoms of dyspepsia and quality of life compared to placebo, H2 receptor antagonists or prokinetics, in people with functional dyspepsia.
We searched in the following electronic databases: the Cochrane Library (to May 2017), MEDLINE (OvidSP; to May 2017), Embase (OvidSP; to May 2017), and SIGLE grey literature (up to May 2017) and clinical trial registries; we handsearched abstracts from conferences up to May 2017. We screened non-systematic reviews, systematic reviews and guidelines to identify any additional trials. We contacted trialists to obtain missing information.
All randomized controlled trials (RCTs) comparing any PPI with placebo, H2 receptor antagonists (H2RAs) or prokinetics for the treatment of FD of at least two weeks' duration. Participants were adults (aged 16 years or greater) with an adequate diagnosis of FD (any validated criteria such as Rome I, II, III or Lancet Working Group).
Two review authors independently assessed eligibility and trial quality, and extracted data. We collected data on dyspeptic symptoms, quality of life and number of overall adverse events. Specific adverse events were beyond the scope of this review.
We identified 25 RCTs from 27 papers (with 8453 participants) studying the effect of PPIs versus placebo, H2RAs or prokinetics for improvement of global symptoms of dyspepsia and quality of life in people with FD. Low-dose PPIs had similar efficacy as standard-dose PPIs, therefore we combined these subgroups for the analysis. PPI was more effective than placebo at relieving overall dyspepsia symptoms in people with FD (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.82 to 0.94; participants = 6172; studies = 18; number needed to treat for an additional beneficial outcome (NNTB) 11; moderate quality evidence). PPIs may have little or no effect compared with H2RAs (RR 0.88, 95% CI 0.74 to 1.04; participants = 740; studies = 2; low quality evidence), and may be slightly more effective than prokinetics (RR 0.89, 95% CI 0.81 to 0.99; participants = 1033; studies = 5; NNTB 16; low quality evidence) at relieving overall dyspepsia symptoms in people with FD. PPIs plus prokinetics have probably little or no effect compared with PPIs alone at relieving overall dyspepsia symptoms (RR 0.85, 95% CI 0.68 to 1.08; participants = 407; studies = 2; moderate quality evidence).There was no difference when subgrouped by Helicobacter pylori status, country of origin, or presence of reflux or Rome III subtypes. There were no differences in the number of adverse events observed between PPIs and any of the other treatments. There were fewer adverse events in the combination of PPI plus prokinetics compared to prokinetics alone (RR 0.60, 95% CI 0.39 to 0.93; participants = 407; studies = 2; moderate quality evidence).
There is evidence that PPIs are effective for the treatment of FD, independent of the dose and duration of treatment compared with placebo. PPIs may be slightly more effective than prokinetics for the treatment of FD; however, the evidence is scarce. The trials evaluating PPIs versus prokinetics are difficult to interpret as they are at risk of bias. Although the effect of these drugs seems to be small, the drugs are well tolerated.