November 21 (HealthDay News) -- A new drug called Banzel (rufinamide) has been approved as a supplementary treatment for a severe form of epilepsy called Lennox-Gastaut syndrome, the U.S. Food and Drug Administration announced Friday.

The approval was based on results of a four-month clinical trial that included patients ages 4 to 30. Compared to patients who took a placebo, those who took the drug had 41 percent fewer tonic plus atonic seizures and 20 percent fewer seizures of any type, the agency said in a news release.

Common side effects included headache, dizziness, fatigue, drowsiness, double vision, nausea, vomiting, and problems walking.

As with all other antiepileptic drugs, Banzel will carry a warning that it may increase the risk of suicidal thoughts or behaviors. All patients who take Banzel must be given a patient medication guide that describes the risk of suicidal thoughts and behaviors associated with this class of drugs, the FDA said.

Banzel, manufactured by Eisai Medical Research Inc. of Woodcliff Lake, N.J., was granted "orphan drug status" by the FDA. This designation is given to a drug intended to treat a disease or condition that affects fewer than 200,000 people in the United States.

Lennox-Gastaut syndrome usually begins before age 4 and can be caused by brain malformations, severe head injury, central nervous system infection and inherited degenerative or metabolic conditions. No cause can be found in 30 percent to 35 percent of cases, the FDA said.

Patients with this form of epilepsy may experience periods of frequent seizures mixed with brief, relatively seizure-free periods. They suffer from varying types of seizures, including tonic (stiffening of the body, upward deviation of the eyes, dilation of the pupils, and altered respiratory patterns), atonic (brief loss of muscle tone and consciousness, causing abrupt falls), atypical absence (staring spells), and myoclonic (sudden muscle jerks).

Most children with Lennox-Gastaut syndrome have some degree of impaired intellectual functioning or information processing, as well as developmental delays and behavioral issues.

"This approval offers another treatment option for patients who suffer from these debilitating, severe seizures," Dr. Russell Katz, director of the division of neurology products in the FDA's Center for Drug Evaluation and Research, said in the news release.

SOURCE: U.S. Food and Drug Administration news release, Nov. 21, 2008