This rarely evolves into the serious Stevens-Johnson syndrome. Lamotrigine has recently been approved as adjunctive therapy for generalized seizures of Lennox-Gastaut syndrome in pediatric and adult patients. Tiagabine inhibits the reuptake of gammaaminobutyric acid and consequently increases the amount of this inhibitory neurotransmitter at the synapse. Tiagabine does not appear to affect the levels of other drugs. It is highly protein bound.
Side effects are mostly dose-related symptoms such as dizziness, tremor, and asthenia.
Topiramate is also a carbonic anyhydrase inhibitor, a possible fourth mechanism of action. Clinical trials with topiramate suggested that I in 3 patients with refractory epilepsy will improve significantly with the addition of topiramate to their regimen. Although many patients can be helped by these new drugs, the most common cause of seizure recurrence is noncompliance with a prescribed regimen. Patients should always have drug levels checked before switching to another medication if compliance is in doubt. Medication compliance improves with fewer daily doses which creates a role for the newer long acting preparations such as Tegretol XR and Carbatrol.