Safety of long-term lamotrigine in epilepsy

To examine the safety of lamotrigine (LTG) used in general practice to treat epilepsy.

Information was collected on 11,316 patients who were included in a noninterventional observational cohort study conducted by means of Prescription-Event Monitoring (PEM). A follow-up study provided information on the first 3,994 patients who had taken LTG for > or = 6 months. Incidence density (ID) measurements were used to rank the frequency of the reported events.

Rash was the most frequently reported nonepileptiform event (ID, 19.7/1,000 patient-months) in the first month of treatment and resulted in LTG being stopped in 2% of the 11,316 patients. Rash was reported more frequently among children aged 2-12 years (ID, 29.4/1,000 patient-months) than adults. Other events associated with the use of LTG included headache, drowsiness, nausea, vomiting, malaise, and lassitude. Rare serious events possibly associated with LTG included 12 cases reported as Stevens-Johnson syndrome, four cases of neutropenia, three cases of thrombocytopenia, and two cases of disseminated intravascular coagulation. There were also individual cases of leucopenia, a meningitic reaction, acute renal failure, hepatotoxicity, and a "lupus-like" reaction possibly associated with the drug. No foetal abnormalities were specifically associated with the use of the drug in pregnancy. No death was attributed to LTG.

Patients had severe epilepsy, inadequately controlled by other antiepileptic agents. The results of these two studies suggest that LTG is acceptably safe when used for the treatment of refractory epilepsy.