Lamotrigine is used in the treatment of Bipolar I disorder and a wide variety of seizures including Primary generalized tonic clonic seizures and Partial seizures. It is also used to treat Migraine, Trigeminal neuralgia and Treatment refractory depression. This assay is used to monitor the blood levels, assess compliance and adjust dosage in patients receiving other anticonvulsant agents which interact pharmacokinetically with Lamotrigine.