We searched online databases like PubMed, Cochrane Library, Scopus, and Web of Science till June 2022 for RCTs that compared
metoclopramide alone with placebo or active drugs. The main outcomes were the mean change in
headache score and complete
headache relief. The secondary outcomes were the rescue medications need, side effects,
nausea and recurrence rate. We qualitatively reviewed the outcomes. Then, we performed the network meta-analyses (NMAs) when it was possible. which were done by the Frequentist method using the MetaInsight online software.
RESULTS: Sixteen studies were included with a total of 1934 patients: 826 received
metoclopramide, 302 received placebo, and 806 received other active drugs.
Metoclopramide was effective in reducing
headache outcomes even for 24 h. The intravenous route was the most chosen route in the included studies and showed significant positive results regarding
headache outcomes; however, the best route whether intramuscular, intravenous, or suppository was not compared in the previous studies. Also, both 10 and 20 mg doses of
metoclopramide were effective in improving
headache outcomes; however, there was no direct comparison between both doses and the 10 mg dose was the most frequently used dosage. In NMA of
headache change after 30 min or 1 h,
metoclopramide effect came after
granisetron,
ketorolac,
chlorpromazine, and
Dexketoprofen trometamol. Only
granisetron's effect was significantly higher than
metoclopramide's effect which was only significantly higher than placebo and
sumatriptan. In
headache-free symptoms, only
prochlorperazine was non-significantly higher than
metoclopramide which was higher than other medications and showed significantly higher effects only with placebo. In rescue medication,
metoclopramide's effect was only non-significantly lower than
prochlorperazine and
chlorpromazine while its effect was higher than other drugs and showed higher significant effects only than placebo and
valproate. In the recurrence rate, studies showed no significant difference between
metoclopramide and other drugs.
Metoclopramide significantly decreased
nausea more than the placebo. Regarding side effects,
metoclopramide showed a lower incidence of mild side effects than
pethidine and
chlorpromazine and showed a higher incidence of mild side effects than placebo,
dexamethasone, and
ketorolac. The reported extrapyramidal symptoms with
metoclopramide were
dystonia or
akathisia.
CONCLUSION: A dose of 10 mg IV
Metoclopramide was effective in relieving
migraine attacks with minimal side effects. Compared to other active drugs, it only showed a lower significant effect compared with
granisetron regarding
headache change while it showed significantly higher effects only with placebo in both rescue medication needs and
headache-free symptoms and
valproate in only rescue medication need. Also, it significantly decreased
headache scores more than placebo and
sumatriptan. However, more studies are needed to support our results.