MedGen

Carbamazepine is an aromatic anticonvulsant used to treat epilepsy and other seizure disorders, as well as bipolar disorder and trigeminal neuralgia. Carbamazepine can cause a variety of cutaneous adverse reactions, ranging from mild maculopapular eruptions to Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). The genetic variants HLA-B*15:02 and HLA-A*31:01 are associated with the risk of SJS/TEN. Patients who have at least one copy of the HLA-B*15:02 or HLA-A*31:01 allele (considered HLA-B*15:02 positive or HLA-A*31:01-positive, respectively) have a significantly increased risk for SJS/TEN compared to non-carriers, and it is recommended that they receive an alternate drug. It is important to note that it is possible for a patient without HLA-B*15:02 to develop SJS/TEN. Guidelines regarding the use of pharmacogenomic tests in dosing for carbamazepine have been published in Clinical Pharmacology and Therapeutics by the Clinical Pharmacogenetics Implementation Consortium (CPIC) and are available on the CPIC and PharmGKB websites. [from PharmGKB]