The US Food and Drug Administration (FDA) approved a new use of the anti-seizure medicine Lamictal (lamotrigine) tablets for the treatment of one of the most serious forms of epilepsy -- Primary Generalized Tonic-Clonic (PGTC) seizures, also known as "grand mal" seizures. With this new indication, Lamictal can now be used as add-on therapy to treat PGTC seizures in children aged two and older as well as adults.

This new use marks the fifth FDA approval for Lamictal in epilepsy, making it one of the few antiepileptic drugs with established efficacy in a broad spectrum of seizure types, including partial and generalized seizures. Lamictal is also approved as maintenance therapy for adults with bipolar I disorder.

"Primary generalized tonic-clonic seizures represent one of the most serious forms of epilepsy and one in which additional effective treatments are needed," said Victor Biton, M.D., director of the Arkansas Epilepsy Program, Little Rock, AR, a key investigator for the clinical study supporting this indication. "There are few treatments approved for generalized seizures and fewer approved for both PGTC and partial seizures. The approval of lamotrigine as add-on therapy for patients with PGTC seizures is a testament to the drug's broad spectrum of activity in the treatment of epilepsy."

PGTC seizures are the most common type of generalized seizures, occurring in approximately 20 per cent of patients with epilepsy. These seizures usually occur without warning and are associated with wide-ranging physical and behavioural changes with potentially life-threatening complications. People who experience PGTC seizures become stiff, lose consciousness, and jerk repetitively. Patients may fall to the ground, bite their tongue, and lose bladder control. Serious injury, including broken bones, can occur. The seizure will typically last for a few minutes and then be followed by a period of drowsiness, confusion, headache, and sleep. For some people who have this type of seizure, it can take many hours to fully recover.

"PGTC seizures can be a scary and dangerous experience, especially for young children and their parents," said Edwin Trevathan, M.D., M.P.H., director of the Division of Paediatric and Developmental Neurology at Washington University School of Medicine and Neurologist-in-Chief, St. Louis Children's Hospital, St. Louis, MO, another key investigator of the clinical study. "Since generalized seizures are more common in children than in adults, and since there have been very few new medications approved for use in primary generalized tonic-clonic seizures, this approval is particularly important."

FDA approval of Lamictal as add-on therapy in patients with PGTC seizures was based on a multicenter, placebo-controlled trial in paediatric (³ age 2) and adult patients (n=117). Patients with partial seizures were excluded from this rigorous assessment of Lamictal . In the study, Lamictal was given to patients whose seizures were not well controlled, even while taking one or two other anti-seizure medications.

In this study, Lamictal was highly effective in reducing the frequency of PGTC seizures. Over the entire treatment period, Lamictal significantly reduced PGTC seizures by 66 per cent compared to 34 per cent for the placebo group (p=0.006). Similar effects were seen during the titration and maintenance phases of the study. Significantly more patients receiving Lamictal as maintenance therapy experienced at least a 50 per cent reduction compared to placebo (72 per cent versus 49 per cent, p<0.05). Efficacy was similar across age groups.

Overall, Lamictal was associated with a favourable tolerability profile. The most common drug-related side effects observed in this clinical trial were dizziness (5 per cent Lamictal , 2 per cent placebo), drowsiness (5 per cent Lamictal , 2 per cent placebo), and nausea (5 per cent Lamictal , 3 per cent placebo). This study supports other findings establishing the efficacy and tolerability of Lamictal for a broad range of seizure types and patient ages.