Addition of intravenous magnesium sulfate to standard emergency department migraine therapy with metoclopramide, appears to reduce rather than enhance the effectiveness of treatment. Dr. Jill Corbo, and colleagues from the Albert Einstein College of Medicine in the Bronx, New York, note that there is evidence that magnesium may be helpful in the treatment of migraine headache and that studies in other applications, including asthma treatment, have shown that magnesium sulfate infusions are well tolerated.
To investigate whether such an infusion might be an effective adjunct to migraine therapy, the researchers conducted a double-blind study of 44 patients seeking emergency department migraine treatment.
The subjects, 42 of whom were women, were randomized to receive intravenously 20 mg of metoclopramide and 2 g of magnesium sulfate or 20 mg of metoclopramide and saline placebo at 15-minute intervals. The infusion was stopped after a maximum of three doses or when pain relief was obtained. Examination of visual analogue pain scores demonstrated that those in the placebo group showed greater pain reduction than those in the magnesium group.
Commenting on this unexpected finding, Dr. Corbo told that "our study showed that the addition of magnesium to the standard therapy of metoclopramide may reduce the effectiveness of metoclopramide in relieving migraine." However, she added that "because 95% of the patients were women, the data may not be generalizable to men."