Magnesium in the Prophylaxis of Migraine—A Double-Blind, Placebo-Controlled Study

The migraine prophylactic effect of 10 mmol magnesium twice-daily has been evaluated in a multicentre, prospective, randomized, double-blind, placebo-controlled study. Patients with two to six migraine attacks per month without aura, and history of migraine of at least 2 years, were included. A 4-week baseline period without medication was followed by 12 weeks of treatment with magnesium or placebo. The primary efficacy end-point was a reduction of at least 50% in intensity or duration of migraine attacks in hours at the end of the 12 weeks of treatment compared to baseline. With a calculated total sample size of 150 patients, an interim analysis was planned after completing treatment of at least 60 patients, which in fact was performed with 69 patients (64F, 5M), aged 18–64 years. Of these, 35 had received magnesium and 34 placebo. The number of responders was 1 in each group (28.6% under magnesium and 29.4% under placebo). As determined in the study protocol, this was a major reason to discontinue the t...