Magnesium sulphate has been used in the acute treatment of
migraines; some studies found it to be a highly effective medication in the acute control of
migraine pain and associated symptoms. This randomized, double-blind, placebo-controlled study assesses the effect of
magnesium sulphate on the
pain and associated symptoms in patients with
migraine without aura and
migraine with aura. Sixty patients in each group were assigned at random to receive
magnesium sulphate, 1000 mg intravenously, or 0.9% physiological saline, 10 ml. We used seven parameters of
analgesic evaluation and an analogue scale to assess
nausea,
photophobia and
phonophobia. In the
migraine without aura group there was no statistically significant difference in the patients who received
magnesium sulphate vs. placebo in
pain relief. The
analgesic therapeutic gain was 17% and number needed to treat was 5.98 at 1 h. There was also no statistical difference in relief of
nausea. We did observe a significant lower intensity of
photophobia and
phonophobia in patients who received
magnesium sulphate. In the
migraine with aura group patients receiving
magnesium sulphate presented a statistically significant improvement of
pain and of all associated symptoms compared with controls. The
analgesic therapeutic gain was 36.7% at 1 h. A smaller number of patients continued to have
aura in the
magnesium sulphate group compared with placebo 1 h after the administration of medication. Our data support the idea that
magnesium sulphate can be used for the treatment of all symptoms in
migraine with aura, or as an adjuvant
therapy for associated symptoms in patients with
migraine without aura.