Migraine attacks were frequently diagnosed in the emergency departments. Also intravenous metoclopramide was a commonly used drug in the acute abortive treatment of migraine. However, the role of metoclopramide was based on three randomized, placebo-controlled studies, which were carried out with relatively few patients. Those trials suggested that metoclopramide produced larger improvements in visual analog scale (VAS) scores, however they revealed conflicting results and had significant methodological problems (risk of bias, allocation of concealment, intention-to-treat analysis). The investigators aimed to analyse the effects of intravenous metoclopramide in acute migraine attacks comparing with placebo.