Lamotrigine

Lamotrigine ( luh-MOH-trih-jeen), sold under the brand name Lamictal among others, is a medication used to treat epilepsy and stabilize mood in bipolar disorder. For epilepsy, this includes focal seizures, tonic-clonic seizures, and seizures in Lennox-Gastaut syndrome. In bipolar disorder, lamotrigine has not been shown to reliably treat acute depression in any groups except for the severely depressed; but for patients with bipolar disorder who are not currently symptomatic, it appears to reduce the risk of future episodes of depression. Lamotrigine is also used off label for unipolar depression (major depressive disorder), treatment-resistant obsessive-compulsive disorder, and depersonalization-derealization disorder. Common side effects include nausea, sleepiness, headache, vomiting, trouble with coordination, and rash. Serious side effects include excessive breakdown of red blood cells, increased risk of suicide, severe skin reaction (Stevens–Johnson syndrome), and allergic reactions, which can be fatal. Lamotrigine is a phenyltriazine, making it chemically different from other anticonvulsants. Its mechanism of action is not clear, but it appears to inhibit release of excitatory neurotransmitters via voltage-sensitive sodium channels and voltage-gated calcium channels in neurons. Lamotrigine was first marketed in Ireland in 1991, and approved for use in the United States in 1994. It is on the World Health Organization's List of Essential Medicines. In 2023, it was the most commonly prescribed mood stabilizer and 59th most commonly prescribed medication in the United States, with more than 10 million prescriptions.