Benefit of Anti-Epilepsy Drug Challenged : Medicine: A new study says a powerful drug prescribed to ward off epileptic seizures after severe head injuries has no beneficial effect beyond the first week.
A powerful drug given to tens of thousands of Americans in hopes of preventing epileptic seizures after severe head injuries is effective in the first week after the trauma but has no beneficial effect in the following months and years, a new study has found.
The drug, known as phenytoin or Dilantin, is commonly prescribed to many of the 420,000 people hospitalized with head injuries each year. Many of the patients, injured in car crashes and other accidents, take the drug for six months to a year, physicians say.
In the study, published today in the New England Journal of Medicine, University of Washington researchers in Seattle found that the drug cut the risk of seizures by 75% in the first seven days. But in the following two years, the drug had no effect in reducing the chance of seizures.
“The really significant thing (about the study) is that these people who already are having trouble don’t need additional trouble from medication they don’t need,” said Dr. W. Allen Hauser, a Columbia University neurologist who wrote an editorial accompanying the study.
Phenytoin, which is also used widely to treat other forms of epilepsy, can have significant side effects. They range from bleeding gums and clumsiness to fever, mood changes, slurred speech and irritability.
About half a million Americans suffer brain injuries each year as a result of automobile accidents, falls, fights and other mishaps. About 15% of those are believed to be severe enough to create a significant risk of epilepsy in the year after the injury.
For several decades, many physicians have recommended anti-convulsant drugs like phenytoin in hopes of preventing seizures. Previous studies of their effectiveness have been faulted for methodological limitations, and the results have been inconclusive.
The new study involved 404 patients with serious head trauma. About half were placed on phenytoin, half were not; then both groups were followed for two years.
During the first seven days, 3.6% of the patients on phenytoin had seizures--far fewer than the 14.2% who had seizures without the drug. But by the end of the first year, 21.5% of the drug group and 15.7% of the non-drug group had had seizures.
By the end of the second year, the rates were 27.5% and 21.1%, respectively.
The researchers reported, “We conclude that phenytoin reduces the incidence of seizures in the first week after injury, but not thereafter.”
In his editorial, Hauser concluded that early use of the drug after severe head injury “may be warranted to prevent early seizures and their complications” but that prolonged therapy “does not seem justified.”
Hauser noted that the findings are unlikely to halt the search for a drug that might prevent the development of post-traumatic epilepsy. Other anti-convulsant drugs might be considered, as well as anti-epileptics in conjunction with anti-convulsants, he said.
