Efficacy of intravenous magnesium sulfate in the treatment of acute migraine attacks

Objective.-To study the efficacy and tolerability of 1 g of intravenous mag nesium sulfate as acute treatment of moderate or severe migraine attacks. Background.-Migraine is a common disorder in which not only the pain but al so the accompanying symptoms such as nausea and vomiting reduce activity an d productivity, of sufferers. Many drugs used for the treatment of acute mi graine attacks have many side effects, are not well tolerated, are ineffect ive in some patients, or cannot be used during pregnancy or in patients wit h ischemic heart disease. Magnesium deficiency has been proposed to play a role in the pathophysiology of migraine, and recently treatment of migraine with magnesium has gained considerable interest. Methods.-This was a randomized, single-blind, placebo-controlled trial incl uding 30 patients with moderate or severe migraine attacks. Fifteen patient s received 1 g intravenous magnesium sulfate given over 15 minutes. The nex t 15 patients received 10 mt of 0.9% saline intravenously. Those in the pla cebo group with persisting complaints of pain or nausea and vomiting after 30 minutes also received 1 g magnesium sulfate intravenously over 15 minute s. The patients were assessed immediately after treatment, and then 30 minu tes and 2 hours later. Intensity of pain, accompanying symptoms, and side e ffects were noted. Results.-All patients in the treatment group responded to treatment with ma gnesium sulfate. The pain disappeared in 13 patients (86.6%);it was diminis hed in 2 patients (13.4%); and in all 15 patients (100%), accompanying symp toms disappeared. In the placebo group, a decrease in pain severity but per sisting nausea, irritability, and photophobia were noted in 1 patient (6.6% ). Accompanying symptoms disappeared in 3 patients (20%) 30 minutes after p lacebo administration. All patients initially receiving placebo were subseq uently given magnesium sulfate. All of these patients responded to magnesiu m sulfate. In 13 patients (93.3%), the attack ended; in 1 patient (6.6%), p ain intensity decreased; and in all 15 patients (100%), accompanying sympto ms disappeared. Both the response rate (100% for magnesium sulfate and 7% f or placebo) and the pain-free rate (87% for magnesium sulfate and 0% for pl acebo) showed that magnesium sulfate was superior to placebo. Twenty-six pa tients (86.6%) had mild side effects which did not necessitate discontinuin g treatment during magnesium sulfate administration. Conclusion.-Our results show that 1 g intravenous magnesium sulfate is an e fficient, safe, and well-tolerated drug in the treatment of migraine attack s. It is possible that magnesium sulfate could be used in a broader spectru m of patients than other drugs commonly used for attack treatment. In view of these results, the effect of magnesium sulfate in acute migraine should be examined in large-scale studies.