Study finds it generally safe to withdraw anti-seizure medication in children with epilepsy

Dec 8 2008

A new Mayo Clinic study found that it is generally safe to withdraw anti-seizure medications in children with epilepsy who have achieved seizure-freedom while on the medication.

Researchers found that these children were not at high risk of subsequently developing intractable epilepsy. The study will be presented on Sunday, Dec. 7, at the American Epilepsy Society's annual meeting in Seattle.

Epilepsy is a disorder characterized by the occurrence of two or more seizures. It affects more than 3 million Americans. Approximately 10 percent of affected children have intractable epilepsy, a condition in which medications alone do not control seizures and seizures have a disabling effect on quality of life.

"It is often recommended that children with epilepsy who become seizure-free on anti-seizure medications be withdrawn from the drugs to avoid side effects of long-term use. Those potential side effects include cognitive slowing, incoordination, weight change, behavioral decline, and liver damage," says Katherine Nickels, M.D., a Mayo Clinic pediatric neurologist and an author of this study. "However, few previous studies had examined the risk of intractable epilepsy following withdrawal of anti-seizure medication, and the reported risks varied widely."

Dr. Nickels and a team of Mayo Clinic researchers set out to determine the frequency of intractable epilepsy in children who withdrew from anti-seizure medication after a period of seizure-freedom. The team reviewed the records of 241 children, ages 1 month to 16 years, who were diagnosed with new-onset epilepsy between 1990 and 2000. They identified 152 children who were diagnosed and treated with anti-seizure medication and had at least five years of follow-up. Of those, 56 children (37 percent) achieved seizure-freedom and were withdrawn from the medication. After an average follow-up of eight years, 20 children (36 percent) experienced at least one seizure recurrence. Fifteen of these children re-started the anti-seizure medication, and eight (53 percent) achieved seizure-freedom within one year, two (13 percent) achieved seizure-freedom after two years and only three (20 percent) developed intractable epilepsy. Overall, only 5 percent of the 56 children who withdrew from anti-seizure medication following seizure-freedom developed intractable epilepsy.

"The risk of children developing intractable epilepsy after withdrawal of anti-seizure medication was only 5 percent, which is similar to the risk of intractable epilepsy at the time of initial diagnosis of epilepsy in children," says Dr. Nickels. "Therefore, the children who achieve seizure-freedom on anti-seizure medication should be considered for withdrawal without high risk of intractable epilepsy."