Magnesium Drip Fails to Improve Stroke Outcomes

Placing a magnesium intravenous (IV) drip in the ambulance on the way to the hospital does not improve stroke outcomes, according to a new study.

Researchers at the University of California Los Angeles (UCLA; USA) conducted a multicenter, randomized, double-blinded, placebo-controlled, clinical trial to develop and validate techniques to perform pivotal trials of therapies for treating acute stroke in the prehospital setting. In this context, the FAST-MAG study enrolled 1,700 patients to examine if paramedic initiation of rate-limiting IV infusion of 4 grams of the neuroprotective agent magnesium sulfate in the field (continued in the hospital for 24 hours) is an efficacious and safe treatment for acute stroke.


The results showed that disability at three months was the same with magnesium sulfate or placebo, with a mean modified Rankin score of 2.7 in both groups; 74% of the patients started the study drug within 60 minutes of stroke onset. However, the trial was seen as successful, since it demonstrated that field enrollment of acute stroke patients is a practical and feasible strategy for phase 3 stroke trials, permitting enrollment of greater numbers of patients in the hyperacute time windows. The study describing study rationale and results was published in the February 2014 issue of the International Journal of Stroke.

“The methods developed in this trial and the patient data from this trial are going to be made publicly available so the techniques in the trial can be used to test other promising agents in the pipeline,” said lead author Jeffrey Saver, MD. “The strategies can't be employed for prehospital thrombolytic therapy at this point, but there are starting to be trials moving in that direction.”

In acute ischemic stroke, the volume of salvageable brain tissue is maximal at onset and declines rapidly with time. Prehospital interventions would enable delivery of neuroprotective agents to stroke patients in the hyperacute period when they are potentially most effective. Magnesium sulfate dilates cerebral blood vessels to increase flow, and it has been shown to be neuroprotective in randomized trials of other conditions, such preterm birth, and cardiac arrest.

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