Lamotrigine

Lamotrigine, sold as the brand name Lamictal among others, is an anticonvulsant medication used to treat epilepsy and bipolar disorder. For epilepsy, this includes focal seizures, tonic-clonic seizures, and seizures in Lennox-Gastaut syndrome. In bipolar disorder, it is used to treat acute episodes of depression and rapid cycling in bipolar type II and to prevent recurrence in bipolar type I. Lamotrigine, sold as the brand name Lamictal among others, is an anticonvulsant medication used to treat epilepsy and bipolar disorder. For epilepsy, this includes focal seizures, tonic-clonic seizures, and seizures in Lennox-Gastaut syndrome. In bipolar disorder, it is used to treat acute episodes of depression and rapid cycling in bipolar type II and to prevent recurrence in bipolar type I. Common side effects include sleepiness, headache, vomiting, trouble with coordination, and rash. Serious side effects include lack of red blood cells, increased risk of suicide, Stevens-Johnson syndrome, and allergic reactions. Concerns exist that use during pregnancy or breastfeeding may result in harm. Lamotrigine is a phenyltriazine, making it chemically different from other anticonvulsants. How it works is not exactly clear. It appears to increase the action of gamma-aminobutyric acid (GABA), the main inhibitory neurotransmitter in the central nervous system and decrease voltage-sensitive sodium channels. Lamotrigine was first marketed in the United Kingdom in 1991 and approved for use in the United States in 1994. It is on the World Health Organization's List of Essential Medicines, the most effective and safest medicines needed in a health system. The wholesale cost in the developing world is about 3.57 USD per month as of 2015. In the United States, this amount has a wholesale cost of about 4.64 USD. Lamotrigine is used for the treatment of partial seizures. It is considered a first-line drug for primary generalised tonic-clonic seizures (includes simple partial, complex partial, and secondarily generalised seizures), and as an adjuvant therapy in partial seizures (focal onset tonic-clonic, atypical absence, myoclonic, and due to Lennox-Gastaut syndrome). It is also used as an alternative medication for absence seizure and atypical absence, myoclonic, and atonic seizures. It is also appropriate for the treatment of Lennox–Gastaut syndrome. It is one of a small number of FDA-approved therapies for this severe form of epilepsy. Lamotrigine reduces the frequency of LGS seizures, and is one of two medications known to decrease the severity of drop attacks. Combination with valproate is common, but this increases the risk of lamotrigine-induced rash, and necessitates reduced dosing due to the interaction of these drugs. Lamotrigine is approved in the US for maintenance treatment of bipolar I disorder and bipolar II disorder. While the anticonvulsants carbamazepine and valproate are predominantly antimanics, lamotrigine is most effective for preventing the recurrent depressive episodes of bipolar disorder. The drug seems ineffective in the treatment of current rapid-cycling, acute mania, or acute depression in bipolar disorder; however, it is effective at prevention of or delaying of manic, depressive, or rapid cycling episodes. According to studies in 2007, lamotrigine may treat bipolar depression without triggering mania, hypomania, mixed states, or rapid-cycling. Therapeutic benefit is less evident when lamotrigine is used to treat a current-mood episode. It has not demonstrated effectiveness in treating acute mania, and there is controversy regarding the drug's effectiveness in treating acute bipolar depression. While the 2002 American Psychiatric Association (APA) guidelines recommend lamotrigine as a first-line treatment for acute depression in bipolar II disorder, their website notes that the guidelines, being more than five years old, 'can no longer be assumed to be current'. A paper written in 2008 by Nassir et al. reviewed evidence from trials that were unpublished and not referenced in the 2002 APA guidelines, and it concludes that lamotrigine has 'very limited, if any, efficacy in the treatment of acute bipolar depression'. A 2008 paper by Calabrese et al. examined much of the same data, and found that in five placebo-controlled studies, lamotrigine did not significantly differ from placebo in the treatment of bipolar depression. However, in a meta-analysis of these studies conducted in 2008, Calabrese found that lamotrigine was effective in individuals with bipolar depression, with a number needed to treat (NNT) of 11, or 7 in severe depression. A 2013 review about lamotrigine concluded that it is recommended in bipolar maintenance when depression is prominent and that more research is needed in regard to its role in the treatment of acute bipolar depression and unipolar depression. Furthermore, no information to recommend its use in other psychiatric disorders was found. Off-label uses include the treatment of peripheral neuropathy, trigeminal neuralgia, cluster headaches, migraines, visual snow, and reducing neuropathic pain, although a systematic review conducted in 2013 concluded that well-designed clinical trials have shown no benefit for lamotrigine in neuropathic pain. Off-label psychiatric usage includes the treatment of treatment-resistant obsessive-compulsive disorder, depersonalization disorder, hallucinogen persisting perception disorder, schizoaffective disorder, borderline personality disorder, and post-traumatic stress disorder.