In line with the available evidence, guidelines, and labeling, carbamazepine may be used in non-HLA-B*1502 carriers. In the case of those who carry one or two copies of HLA-B*1502 alleles (HLA-B*1502 positive), alternative agents should be considered. Clinicians should bear in mind that alternative agents (phenytoin, fosphenytoin, oxcarbazepine, eslicarbazepine acetate, and lamotrigine) also show evidence of hypersensitivity reactions in carriers of the HLA-B*1502 allele.27 For HLA-B*1502-positive patients who previously received carbamazepine for period of more than 3 months, a therapeutic switch is optional since the highest risk of the development of dermatologic complications occur in the first months of the therapy.31,32 A meta-analysis of studies published as of 2011 identified that the specificity and sensitivity of HLA-B*1502 testing were 0.88 and 0.96, respectively. Across studies, the odds of SJS or TEN were 113.4 times greater in HLA-B*1502 carriers compared with noncarriers.30
