Asian patients who receive phenytoin or fosphenytoin (a phenytoin prodrug that is intended for parenteral administration) for epilepsy may be at risk of developing serious skin reactions, such as Stevens-Johnson syndrome or toxic epidermal necrolysis, warned the US Food and Drug Administration (FDA) in late November.
The warning is based on preliminary data from an ongoing investigation (http://www.fda.gov/cder/drug/infopage/phenytoin_fosphenytoin/default.htm). Previously, the FDA had cautioned that another antiepileptic drug, carbamazepine, posed a similar risk for Asian patients.
Recent studies suggest that individuals who carry the HLA-B*1502 allele of the human leukocyte antigen gene may be more likely to develop severe skin conditions. This particular variant occurs predominantly in Asian populations, including individuals of Han Chinese, Filipino, Malaysian, South Asian Indian, or Thai decent.
The FDA has advised physicians to test Asian patients for the HLA-B*1502 allele prior to prescribing carbamazepine and to consider the potential risk of . . . [Full Text of this Article]
