Introduction: Lamotrigine is an antiepileptic agent used in a wide range of seizure disorders among the elderly. In rare cases, it can induce a drug hypersensitivity syndrome (DHS).
Cases: DHS due to lamotrigine was observed in two patients (85 and 91 years-old). The first case was characterized by febrile erythema with eosinophilia and the second by isolated fever. Lamotrigine was replaced by sodium valproate for one patient. Both patients had satisfactory outcomes after discontinuing lamotrigine.
Discussion: Lamotrigine can induce DHS that is clinically and biologically similar to the DHS observed with standard antiepileptic drugs. It may involve concomitant or consecutive treatment with other antiepileptic agents, in particular, valproate acid, which decreases lamotrigine clearance. Potentially serious and even fatal, these adverse reactions are to be feared in a population with multiple comorbidities and can cause harmful diagnostic mistakes. They are especially fearsome in geriatric populations with high epilepsy rates.