Intravenous magnesium for acute benign headache in the emergency department: a randomized double-blind placebo-controlled trial.

BACKGROUND

Magnesium deficiency may play a role in the pathogenesis of migraines and other headaches. Studies in outpatient clinics have found that magnesium administered intravenously (IV) reduces headache pain. We investigated the effectiveness of IV magnesium in patients with acute benign headache who presented to the emergency department (ED).

METHODS

This randomized double-blind placebo-controlled trial compared 2 g of IV magnesium versus placebo for the treatment of patients with acute benign headache who presented to the EDs of two teaching hospitals. Pre- and post-treatment pain scores were measured on a 100-mm visual analog pain scale.

RESULTS

Forty-two patients were randomized, 21 in each treatment group. Treatment groups had similar baseline characteristics. After treatment, placebo recipients reported an 8-mm median improvement in pain, and magnesium recipients had a 3-mm improvement (p = 0.63). We found no statistically significant difference between groups for any secondary outcomes; however, the patients who received magnesium had significantly (p = 0.03) more side effects than did those in the placebo group.

CONCLUSIONS

We found no benefit to using IV magnesium to treat patients with acute benign headache who present to the ED.