Pain reduction and adverse effects of intravenous metoclopramide for acute migraine attack: A systematic review and meta-analysis of randomized-controlled trials

BACKGROUND: Metoclopramide may be used to treat people suffering from acute migraine. However, no comprehensive investigation on this issue has been recorded. This review will provide more solid evidence for the use of metoclopramide in treating acute migraine. AIM: To compare the efficacy of intravenous metoclopramide with other therapies in migraine attack treatment in an emergency department (ED). METHODS: We included randomized controlled trials of participants older than 18 years with acute migraine headaches, which included at least one arm that received intravenous (IV) metoclopramide at the ED. A literature search of PubMed, Web of Science, Cochrane Collaboration, and Reference Citation Analysis on December 31, 2021 retrieved other drugs or placebo-controlled studies without language limitation. The risk of bias was assessed using the Cochrane risk of bias tool. The primary endpoint was pain reduction at 60 min or closest to 1 h after treatment, as measured by the pain scale. Secondary endpoints included adverse effects or reactions resulting from metoclopramide or comparisons. RESULTS: Fourteen trials with a total of 1661 individuals were eligible for review. The risk of bias ranged from low to intermediate. IV metoclopramide administration was not associated with higher pain reduction at 1 h (Standard mean difference [SMD] = -0.03, 95% confidence interval [CI]: -0.33-0.28, P = 0.87). However, metoclopramide was associated with better pain reduction than placebo (SMD = 1.04, 95%CI: 0.50-1.58, P = 0.0002). In addition, side effects were not significantly different between IV metoclopramide and other drugs or placebo (odds ratio [OR] = 0.76, 95%CI: 0.48-1.19, P = 0.09 and OR = 0.92, 95%CI: 0.31-2.74, P = 0.54, respectively). CONCLUSION: Metoclopramide is more effective than placebo in treating migraine in the ED. Despite the observed tendency of decreased side effects, its effectiveness compared to other regimens is poorly understood. More research on this area is needed to treat migraine in acute care settings effectively.