Lamotrigine induced Stevens-Johnson syndrome: a case report

This case is about a young girl who had lamotrigine induced Stevens Johnson syndrome which is known to occur but is rare. Lamotrigine was started when the patient was also receiving valproate for several years; no adverse effects, including any minor skin rash, were recorded while on valproate monotherapy. Valproate is known to augment lamotrigine availability via reduced glucuronidation, which increases the risk of serious rash if patients are concomitantly given lamotrigine. This suggests that a drug-drug interaction between lamotrigine and valproate did contribute to the development of Stevens-Johnson syndrome. Stevens-Johnson syndrome was linked in this case with a higher dose of lamotrigine, suggesting a dose-dependent toxicity. We emphasize that a rapid dose escalation of lamotrigine, even a single higher dose, could expose to an unacceptable risk of Stevens-Johnson syndrome, particularly in patients taking valproate.