Risk of Adverse Events Associated with Domperidone and Metoclopramide in Gastroparesis: Systematic Review and Meta-analysis.

Background: Dopamine antagonists are the main pharmacological options to treat gastroparesis. The aim of this study was to conduct a systematic literature review (SLR) to evaluate the profile of adverse events (AEs) of dopamine antagonists used in the treatment of children and adults with gastroparesis.

Methods: We searched EMBASE and MEDLINE up to March 25, 2021, for relevant clinical trials and observational studies. We conducted a proportional meta-analysis to estimate the pooled occurrence of AEs (%), with 95% confidence interval (CI), from arm-level data across studies and the comparative occurrence of AEs from placebo-controlled clinical trials (odds ratio [OR] with 95% CI).

Results: We identified 28 studies assessing AEs experienced by patients treated for gastroparesis with domperidone and metoclopramide; 22 studies contributed data to the meta-analyses. Cardiovascular, neurological, and endocrine AEs were commonly observed, with point incidences varying from 1 to > 50%. Clinically important AEs, such as QTc prolongation, occurred in 5% of patients treated with domperidone (95% CI: 3.32-8.62). Restlessness, an extrapyramidal AE, occurred in 15% of patients (95% CI: 7.48-26.61) treated with metoclopramide, with a 7-fold increase compared with patients receiving placebo (OR: 7.72; 95% CI: 1.27-47.05). Variation in terminology to describe extrapyramidal events precluded further pooled analyses. Additional meta-analyses were not feasible due to discrepancies in the assessment and reporting of the AEs.

Conclusions: The evidence confirms concerns of cardiovascular, extrapyramidal, and endocrine AEs in patients with gastroparesis treated with domperidone and metoclopramide. Imprecise AE reporting limits firm interpretation and conclusions.

Registration: PROSPERO international prospective register of systematic reviews (registration number: CRD42021248888).