It’s now commonly used for brain injuries, and the researchers felt it was important to find out “whether we’re treating patients with a useful drug, a harmful drug or a useless drug,’’ Whyte said.
The study was done in the U.S., Denmark and Germany and involved 184 severely disabled patients, about 36 years old on average. About a third were in a vegetative state, meaning unconscious but with periods of wakefulness. The rest were minimally conscious, showing some signs of awareness. They were treated one to four months after getting injured, a period when a lot of patients get better on their own, Giacino noted.
They were randomly assigned to receive amantadine or a dummy drug daily for four weeks. Both groups made small but significant improvement, but the rate of recovery was faster in the group getting amantadine. When treatment stopped, recovery in the drug group slowed. Two weeks later, the level of recovery in the two groups was about the same.
There was no group difference in side effects, which included seizure, insomnia and rigid muscles.
The study was short, and the effect on long-term outcome is unknown. But Giacino said the drug still has value even if it only hastens recovery.
“What condition would we not jump for joy if we could have it over with faster?’’ he said.
The study didn’t include those with penetrating head injuries, like the gunshot wound former Rep. Gabrielle Giffords suffered, but Giacino said the drug should have similar effects in those patients. Whether it would work in patients with brain injuries not caused by trauma, such as a stroke, isn’t known.
Whyte said the researchers want to test the drug for longer periods.
Dr. Ramon Diaz-Arrastia said the results were welcome news in a field that has seen many failed efforts. He is director of clinical research at the government’s Center for Neuroscience and Regenerative Medicine, which works with the military and government scientists on brain injury research.
“It’s an important step toward developing better therapies,’’ he said.
Since amantadine is so commonly used, he said U.S. troops with severe brain injuries in Iraq or Afghanistan probably get it, or should get it now. Since 2000, some 233,000 troops have suffered traumatic brain injuries, including about 6,100 serious cases, many of them from bomb blasts or shrapnel.
Laura Bacon said amantadine seems to be helping her brother recover from a car accident in Vermont last October. Nicholas Gnazzo, 47, of Rochester, N.H., was in a coma for weeks before he was taken for rehabilitation to Spaulding, where doctors put him on amantadine in January.
Since then he has been more alert, able to communicate with nods or gestures — like pointing to his eyes when he wants his glasses, his sister said. Giacino agreed her brother has gotten better, but whether it is because of the drug can’t be determined. Gnazzo wasn’t part of the study.
“It’s been four months now, and we know we still have a long way to go,’’ Bacon said. “Anything that could be faster — or feel faster to us — is a positive.’’