Pfizer Inc has received US Food and Drug Administration (FDA) approval to market Lyrica (pregabalin) for adjunctive treatment of partial onset seizures in adults with epilepsy.

Partial onset seizures represent over half of all seizures in patients with epilepsy, a chronic neurological condition affecting nearly three million Americans. While epilepsy can be caused by genetic predisposition or head injuries, in most cases the cause is unknown. Despite the availability of current treatments, many patients still experience uncontrolled seizures, a Pfizer release said.

"Lyrica represents a significant therapeutic advance for millions of people suffering from epilepsy," said Dr Joseph Feczko, Pfizer's chief medical officer. "This is an effective medicine that can help people with epilepsy gain better seizure control, and as a result, improve their quality of life."

The efficacy of Lyrica was established in three double-blind, controlled trials involving 1,052 patients. At the start of treatment with Lyrica, patients experienced approximately 10 seizures a month despite taking one to three other antiepileptic medications. Patients receiving adjunctive treatment with Lyrica experienced a reduction in the frequency of partial seizures by up to 51 per cent. Lyrica can be given to patients two times or three times a day.

"There is a significant need for new antiepileptic drugs, as no new agent has been introduced in five years," said Dr Jacqueline French, Professor of Neurology, University of Pennsylvania Medical School. "Poor seizure control in patients with epilepsy has emotional and functional consequences that can significantly diminish quality of life. In clinical trials, Lyrica significantly reduced the frequency of seizures in patients who continue to experience seizures despite their standard treatment with antiepileptic medicines."

The most common side effects across all Lyrica clinical trials were dizziness, somnolence, dry mouth, peripheral edema, blurred vision, weight gain and difficulty with concentration/attention. The discontinuation rate due to side effects was low.

Lyrica will be designated a controlled substance, recommended for classification in the category with lowest potential for abuse or misuse relative to controlled substances in other categories. Lyrica will be available in pharmacies in the fall.

The FDA approved Lyrica in December 2004 for the management of diabetic peripheral neuropathy and postherpetic neuralgia. Developed by Pfizer, Lyrica is an alpha-2-delta ligand with a newly defined mechanism of action that is believed to work by calming hyper-excited neurons.

Lyrica has been approved for neuropathic pain and epilepsy in 46 countries outside of the United States.