The efficacy of magnesium oxide and sodium valproate in prevention of migraine headache: a randomized, controlled, double-blind, crossover study.

Migraine is a disabling disorder that affects the quality of life of patients. Different medications have been used in prevention of migraine headache. In this study, we evaluated the effectiveness of magnesium oxide in comparison with valproate sodium in preventing migraine headache attacks. This is a single-center, randomized, controlled, crossover trial which is double-blind, 24-week, 2-sequence, 2-period, 2-treatment. After patient randomization into two sequences, the intervention group received magnesium oxide 500 mg and the control group received valproate sodium 400 mg two tablets each day (every 12 h) for 8 weeks. The primary efficacy variable was reduction in the number of migraine attacks and number of days with moderate or severe headache and hours with headache (duration) per month in the final of 8 weeks in comparison with baseline. Seventy patients were randomized and seven dropped out, leaving 63 for analysis. In an intention-to-treat analysis, 31 patients were in group 1 (magnesium oxide-valproate) and 32 patients were in group 2 (valproate-magnesium oxide). The mean number of migraine attacks and days per month was 1.72 ± 1.18 and 2.09 ± 1.70, with a mean duration of 15.50 ± 21.80 h in magnesium group and 1.27 ± 1.27 and 2.22 ± 1.96, with a mean duration 13.38 ± 14.10 in valproate group. This study has shown that 500 mg magnesium oxide appears to be effective in migraine prophylaxis similar to valproate sodium without significant adverse effect.