Toxic epidermal necrolysis due to concomitant use of lamotrigine and valproic Acid

Anti-epileptic drugs can be associated with a wide spectrum of cutaneous adverse reactions ranging from simple maculopapular rashes to more severe and life threatening reactions like Stevens-Johnson syndrome and toxic epidermal necrolysis. These rashes are well documented with older antiepileptic drugs like phenytoin, phenobarbitone and carbamazapine. Lamotrigine is a newer, unrelated antiepileptic drug that causes skin rashes in 3-10% of new users. Higher starting dose or rapid escalation, concurrent treatment with valproic acid, and a previous history of a rash with other antiepileptic drugs are well recognized risk factors for lamotrigine related serious rashes. We report two patients with toxic epidermal necrolysis, resulting from concomitant use of lamotrigine and valproic acid. It is emphasized that clinicians adhere to the recommended dosage guidelines and adopt a slow dose titration when initiating treatment with lamotrigine.