A 14-year-old boy is brought to the physician by his mother for seizures. His seizures are usually characterized as a blank stare and lip smacking, followed by generalized shaking. The patient occasionally bites his tongue during the episodes and feels confused afterwards. His seizures have been refractory to various antiepileptic medications, and he is started on lamotrigine. The patient should be instructed to see his physician immediately if which of the following symptoms occurs?

Question

A 14-year-old boy is brought to the physician by his mother for seizures.  His seizures are usually characterized as a blank stare and lip smacking, followed by generalized shaking.  The patient occasionally bites his tongue during the episodes and feels confused afterwards.  His seizures have been refractory to various antiepileptic medications, and he is started on lamotrigine.  The patient should be instructed to see his physician immediately if which of the following symptoms occurs?

Quizplus · Accepted Answer

Lamotrigine is an anticonvulsant that works by blocking voltage-gated sodium channels. It can be used to treat partial and generalized seizures and is also effective for bipolar disorder. Up to 10% of patients using lamotrigine will develop benign rash; however, a potentially life-threatening rash due to Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) occurs in up to 1% of patients (particularly children). SJS and TEN represent different endpoints along the same disease continuum: SJS involves <10% of the body surface area and TEN has >30% involvement. Patients with SJS/TEN typically develop flu-like symptoms (eg, fever, malaise, myalgias) followed by extensive cutaneous and mucosal lesions. Histopathologically, lesions are characterized by epidermal necrosis and subepidermal bullae. The first appearance of rash requires discontinuation of the drug immediately as SJS/TEN and benign rash cannot be distinguished reliably. Other anticonvulsants associated with SJS/TEN include carbamazepine, phenobarbital, and phenytoin. (Choices A, C, and D) Gastrointestinal symptoms (eg, abdominal pain, heartburn, diarrhea) are relatively common with lamotrigine and other anticonvulsant medications but are usually not life-threatening. (Choices B and F) Although SJS/TEN can present with a flu-like prodrome (eg, fever, malaise, myalgia), cough or urinary symptoms would be atypical. Educational objective: Lamotrigine can be used to treat partial and generalized seizures and works by blocking voltage-gated sodium channels. Stevens-Johnson syndrome and toxic epidermal necrolysis are rare, life-threatening adverse effects characterized by flu-like symptoms followed by widespread mucocutaneous epidermal necrosis.

A 14-Year-Old Boy Is Brought to the Physician by His