Topiramate Available For Treatment Of Epilepsy

For release: Monday, December 30, 1996

A new drug for epilepsy, topiramate, with particular effectiveness for partial seizures, developed in part by scientists at the National Institute of Neurological Disorders and Stroke (NINDS), is now available to the public. The drug received approval by the Food and Drug Administration on December 24.

The drug will be used in conjunction with other antiepileptic drugs to treat adult patients with partial seizures. Half of the 2.5 million Americans who have epilepsy have partial seizures, which commonly produce such symptoms as jerking of an arm or leg, a blank stare with loss of awareness of one's surroundings, or involuntary movements, such as picking at one's clothes.

"This drug will make a real difference in the lives of thousands of Americans with difficult-to-control epilepsy," said Philip H. Sheridan, M.D., Acting Chief of the NINDS Epilepsy Branch. "Topiramate should substantially expand the treatment options currently available to neurologists for their patients by offering safety and effectiveness."

Epilepsy is a condition of repeated seizures caused by excessive or abnormal brain electrical discharges. The seizures may appear as convulsions, a blank stare, muscle jerks, odd sensations, or a loss of awareness, depending on the area of the brain affected.

Topiramate was submitted to the NINDS Antiepileptic Drug Development (ADD) Program in September 1981 for evaluation of its therapeutic potential. Scientists from the Institute's Epilepsy Branch worked closely with the pharmaceutical company during topiramate's preclinical development.

Although topiramate's mechanism of action has not been fully identified, it appears to work differently than the most commonly used anticonvulsant agents, phenytoin, carbamazepine, and valproic acid. The drug is also thought to be less toxic than many other antiepileptic drugs and has a long duration of action. The most common side effects shown in clinical trials of topiramate were drowsiness, dizziness, clumsiness, fatigue, confusion, and difficulty concentrating, all often found in those taking antiepileptic drugs.

Studies of patients using topiramate showed a 34 to 87 percent or greater reduction in seizure frequency. Some patients enrolled in topiramate trials became seizure free. Topiramate trials also showed that the drug has no metabolic interactions with other antiepileptic drugs.

Topiramate is one of over 18,000 compounds evaluated by the NINDS ADD Program since 1975. The ADD Program is a cooperative effort between the Federal Government, the pharmaceutical industry, and academia to develop new therapeutic agents to treat epileptic seizures. It combines expertise in both preclinical and clinical areas of drug development. Since its establishment, the NINDS ADD Program has assisted in the development of carbamazepine, valproate, clonazepam, felbamate, and lamotrigine.

Topiramate is already available in the United Kingdom for treatment of partial seizures. It will be marketed in the United States under the trade name Topamax by its commercial developer, Ortho-McNeil, a Johnson & Johnson company based in Raritan, New Jersey.

The NINDS, one of the National Institutes of Health located in Bethesda, Maryland, is the nation's leading supporter of research on the brain and nervous system and a lead agency for the Congressionally designated Decade of the Brain.

Originally prepared by Stephanie Clipper, NINDS Office of Communications and Public Liaison.

Date Last Modified: Wednesday, July 16, 2008

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