A 'coffee cocktail' drug could reduce the amount of damage caused by strokes, researchers say.
The drug has as much caffeine as two strong cups of coffee
The drug is as potent as two cups of strong coffee combined with an alcoholic drink.
The drug - a mixture of caffeine and ethanol (alcohol), called caffeinol - had already been shown to limit damage from ischaemic strokes in animal studies.
It has now been shown to be safe in a small study of human stroke patients.
Researchers from the University of Texas Houston Medical School gave caffeinol to 23 male and female stoke patients with an average age of 71.
They found they were able to give the patients lower doses of the drug than animal studies had suggested, while still achieving the same blood levels of caffeinol which had been shown to offer protection in rats.
We don't have many treatments that actually reduce the amount of damage to the brain after a stroke
Professor Martin Brown, University College London
In those tests, an artery supplying blood to the brain was blocked, mimicking what happens in an ischaemic stroke.
It was found the amount of brain damage was reduced by up to 80% if caffeinol was given within three hours.
Further research will now be carried out to test the drug's effectiveness in humans.
Patients can already be given thrombolytic 'clot-busting' drugs, but their effectiveness depends on being given in the immediate aftermath of a stroke.
The researchers found caffeinol could be safely given alongside thrombolytic drugs.
Professor of neurology James Grotta, who led the research, said the research had demonstrated that the combination of caffeine and ethanol may reduce the amount of damage after stroke.
He added: "Neither caffeine or alcohol offered protection alone, but the combination was protective.
"Our goal was to see if we could safely achieve the same blood levels of caffeinol that we achieved in our animal studies.
"We discovered that we could use even lower doses than we used in the animal studies and achieve the blood levels that were neuroprotective in animals."
He added that more work was needed to find the ideal mixture of caffeine and ethanol.
The team will also look at whether combining caffeinol with cooling treatments carries even more benefits.
Other studies have suggested that cooling the brain can limit stroke damage.
Martin Brown, professor of stroke medicine at University College London, told BBC News Online: "This is very exciting. We don't have many treatments that actually reduce the amount of damage to the brain after a stroke."
But he added: "We do have to be rather cautious. There are a huge number of different drugs that seem to work in animal models, but don't then always work in humans."
Professor Brown, said it was not certain how caffeinol worked.
But he said: "Alcohol does have the effect of opening up blood vessels and caffeine, which is beneficial in conditions like migraine, could improve blood flow.
"In addition, these are very safe drugs to give because - obviously - these are drugs which are used by everyone."
The research is published in Stroke: Journal of the American Heart Association.