Abstract: From an initial 1388 citations, we identified 43 studies in 40 papers. Of those, 29 studies with 10,044 participants compared six prokinetics with placebo for the outcome of absence of symptoms or symptom improvement. There was a statistically significant effect of prokinetic treatment in reducing global symptoms of FD (RR of remaining dyspeptic = 0.81, 95% CI 0.74 to 0.89; number needed to treat for an additional beneficial outcome (NNTB) =7, very low-quality evidence) with considerable heterogeneity; I2 = 91% (P < 0.00001). After removing cisapride from the analysis, the effect of prokinetics in global symptom improvement still persisted, compared to placebo (RR 0.87, 95% CI 0.80 to 0.94), but was still based on very low-quality evidence. The result showed persistence of significant improvement in subgroups of studies at unclear or at low risk of bias (RR 0.86, 95% CI 0.80-0.92), and in subgroups by molecules of cisapride (RR 0.71, 95% CI 0.54 to 0.93; NNTB = 4), acotiamide (RR 0.94, 95% CI 0.91 to 0.98; NNTB = 20) and tegaserod(RR 0.89, 95% CI 0.82 to 0.96; NNTB = 14). Ten studies compared different types of prokinetics with each other and the most commonly used comparator was domperidone, 10 mg three times a day (eight of the 10 studies). There was a significantly better post-treatment symptom score in other prokinetics, compared to domperidone (SMD -0.19, 95% CI -0.35 to -0.03, very low-quality evidence), but no difference in reducing global symptom (RR 0.94, 95% CI 0.83 to 1.07), and mean difference symptom scores (SMD -0.13, 95% CI -0.31 to 0.05). We found five studies that assessed quality of life, but there was no benefit in improving quality of life with prokinetic treatment (SMD 0.11, 95% CI -0.10 to 0.33; participants = 1774). The adverse events in individual prokinetics was not different from placebo (RR 1.09, 95% CI 0.95 to 1.25; participants = 3811; studies = 17). However, when we looked at the adverse effects by each prokinetic, there were overall greater adverse effects in the active treatment group with cisapride (RR 1.31, 95% CI 1.03 to 1.65; P = 0.03). The most common side effects were diarrhoea, abdominal discomfort and nausea. The funnel plot was asymmetric (Egger's test, P = 0.02) implying reporting bias or other small-study effects may be, in part, driving the benefit of prokinetics compared to placebo in this meta-analysis. The GRADE assessment of the quality of the evidence in each outcome are mostly low or very low due to concerns around risk of bias in study design, unexplained heterogeneity and possible publication bias. Due to low, or very low, quality of evidence, we are unable to say whether prokinetics are effective for the treatment of functional dyspepsia . We are uncertain which of the individual prokinetic drugs is the most effective as well as whether prokinetics can improve quality of life. Apart from cisapride, prokinetics are well-tolerated. Good quality RCTs are needed to verify the efficacy of prokinetics.

Plain-language summary: We included 43 studies that compared prokinetics with either placebo (powder that has the appearance similar to drug) or another prokinetic for treatment of functional dyspepsia. The studies were limited to those which assessed only adults who presented with upper abdominal discomfort but who did not have a specific cause after investigation. We are uncertain whether prokinetics reduce dyspeptic symptoms, compared to no prokinetic treatment. We are also uncertain which prokinetics had the most efficacy in reducing dyspeptic symptoms, improving post-treatment symptom scores, or improving the mean difference of symptom score. We are uncertain whether prokinetic treatment can improve quality of life. We are uncertain whether prokinetics (except cisapride) differ from no prokinetic in producing unpleasant symptoms. The most common unpleasant symptoms from prokinetics were diarrhoea, abdominal discomfort and nausea. The quality of the evidence was graded as low or very low. We need more research to prove the benefit of prokinetics for treatment in people with functional dyspepsia.