Source: DGNews  |  Posted 3 years ago

By Adi Ferrara

SEATTLE, Wash -- December 7, 2008 -- Several risk factors may predict adverse skin reaction to lamotrigine in children receiving the drug for the treatment of epilepsy. The risk factors include intractable epilepsy, a medical history of skin reactions to other medications (including, but not limited to, other antiepileptic drugs), and polytherapy containing valproate, according to study results presented here at the American Epilepsy Society (AES) 62nd Annual Meeting.

The retrospective study was presented in a poster session on December 6 by author Nebojsa Jovic, MD, Clinic for Neurology and Psychiatry of Children and Youth, Belgrade, Serbia.

Between January 2000 and December 2007, 403 children were treated as outpatients with lamotrigine added on to existing therapy; 109 children were treated as outpatients with lamotrigine monotherapy. Of the 512 children reviewed in this study, 323 had epilepsy with symptomatic aetiology and 189 had epilepsy that was cryptogenic in origin. The children ranged in age from 2 to 17 years (mean 13.6 years).

A total of 21 children developed adverse skin reactions to lamotrigine, consisting of moderate diffuse macular-papular or erythematous rash (14 patients), severe urticarial skin eruption (6 patients, 4 of whom had to be hospitalised), and mild Stevens-Johnson syndrome (1 patient). There were no cases of toxic epidermal necrolysis. In 19 patients, skin reactions occurred an average of 16 days after the start of lamotrigine treatment. Two patients developed a reaction within the first week of therapy.

Fifteen children with symptomatic aetiology (4.6% of all participants with symptomatic aetiology) developed skin reactions, compared with 6 children with cryptogenic aetiology (3.2%). Sixteen of the children with skin reactions had intractable epilepsy and were treated with lamotrigine and an additional drug: valproate (9 children), carbamazepine (3 children), oxcarbazepine (1 child), topiramate (1 child), and primidone (2 children). The other 5 children had received lamotrigine as monotherapy. A history of skin reactions to other medications was noted in 7 of the 21 children (33.3%) who developed lamotrigine skin reactions.

Of the patients who did not experience a skin reaction to lamotrigine, 23 (4.5%) had a history of skin reactions to other medications.

Lamotrigine was discontinued in 20 of the 21 children who developed a reaction. Five patients suffered an increase in seizures during the rash or after lamotrigine withdrawal.

The current study found no evidence of a connection between high titration rates and age younger than 13 years, which were postulated by some researchers as risk factors for lamotrigine-induced skin rash. The risk factors that emerged in this study are intractable epilepsy, symptomatic seizure etiology, coadministration of lamotrigine and valproate, and a history of skin reactions to other medications (including, but not limited to, other antiepileptic drugs).

[Presentation title: Factors Associated With Lamotrigine-Induced Rash in Children With Epilepsy. Abstract 1.206]