Efficacy of intravenous magnesium sulfate in severe migraine attacks

The aim of this open study was to make a preliminary estimate of the efficacy and tolerability of intravenously administered magnesium sulfate (1 g) in comparison to subcutaneously administered sumatriptan in the treatment of severe migraine attacks. The study comprised 22 consecutive patients whose attacks were treated with magnesium sulfate (5 ml of a 20% solution), and the results were compared with those of another group of 14 consecutive patients whose attacks were treated with sumatriptan (6 mg). Immediately before and 10, 20 and 30 minutes after injections, patients reported pain intensity on a verbal 0–10 scale. Pain disappearance or pain relief >50% were considered significant. Efficacy of sumatriptan was superior that of to magnesium sulfate 20 minutes after the injections (p<0.05) and comparable after 30 minutes (magnesium therapy was successful in 68% in comparison to 79% of patients treated with sumatriptan). After only 10 minutes, 3 patients treated with magnesium sulfate were pain free, with the same effect in 5 (22.5%) and 10 (45%) patients after 20 and 30 minutes, respectively. The rate of headache recurrence was low and no major adverse effects were recorded. In conclusion, magnesium sulfate may be a well-tolerated pharmacological alternative for the treatment of severe migraine attacks.