FRIDAY, Feb. 14, 2014 (HealthDay News) -- Giving magnesium to stroke patients while they're being taken to the hospital does not reduce the severity of their disabilities three months later, a new study finds.
Paramedics gave magnesium intravenously to 1,700 stroke patients in California to try to protect their brain cells from the effects of oxygen deprivation. The average time for starting magnesium treatment was 45 minutes after stroke symptoms began, and 74 percent of the patients were started on the treatment within an hour, the study authors noted.
The magnesium was safe, but did not provide any benefits, the researchers found. Ninety days after their stroke, the patients had slight to moderate levels of disability and required assistance to do many of their previous activities, according to findings presented Thursday at the American Stroke Association's International Stroke Conference in San Diego.
Research presented at medical meetings should be viewed as preliminary until published in a peer-reviewed journal.
In animal studies, magnesium was found to widen blood vessels in the brain and increase blood flow, offsetting the dangerous calcium build-up that occurs in cells that are starved of oxygen.
Earlier, small trials with patients showed that giving magnesium up to 12 hours after a stroke caused neither harm nor benefit. However, there were signs that magnesium might be helpful to those who received it within a few hours after their stroke.
"We hoped magnesium would be beneficial, but in any case the study was a success in demonstrating we can get a drug to patients in this early time frame when there is the greatest amount of threatened brain tissue that might still be saved," principal investigator Dr. Jeffrey Saver, director of the stroke center at the University of California, Los Angeles, said in a stroke association news release.
"There are lots of other promising agents in the pipeline that could be helpful, and we now have a system for testing and using them," he added.
Currently, the clot-busting drug tPA is the only immediate treatment for ischemic strokes, which are caused by blocked blood flow. But this drug can't be given until patients undergo brain scans to determine the nature of their stroke.
"Giving tPA in the ambulance before brain imaging is not an option -- it could harm patients having a bleeding type of stroke. Neuroprotective drugs can be delivered in the field as they are safe for both types of stroke," Saver explained in the news release.
The U.S. National Institute of Neurological Disorders and Stroke has more about stroke.