J Pharmacoepidemiol Risk Manage.  2020 Sep;12(2):57-62.

Hypersensitivity to Anticonvulsants

• Ye YM

Abstract

Hypersensitivity reactions due to antiepileptics are rare but potentially fatal reactions associated most commonly with carbamazepine, phenytoin, and lamotrigine. Drug hypersensitivity to antiepileptics generally occurs on first exposure to the drug, with symptoms such as skin rash, fever, and internal organ involvement that develop within several weeks of drug exposure. Pharmacogenetic testing for HLA allele B*15:02 should be considered before commencing carbamazepine in Han Chinese, South Asian, and East Indian patients, whereas HLA-B*15:11 and A*31:01 have been suggested as genetic markers for carbamazepine-induced severe cutaneous adverse reactions in Korean patients. Clinical predictors, such as a history of drug hypersensitivity to aromatic antiepileptics, family history of drug allergy, age, and viral infections, can be helpful for physicians to minimize adverse reactions to an antiepileptic drug. Early diagnosis is most important and the cessation of the implicated drug is primary treatment for antiepileptic drug allergy. Avoidance of other aromatic anticonvulsants (eg, phenytoin, carbamazepine, phenobarbital, primidone, oxcarbazepine, and lamotrigine) is recommended in patients who develop allergic reactions to any one of these agents due to a high degree of crossreactivity among them. Further investigation to understand the pathogenic mechanisms (especially in aspects of genetics and immunologic mechanisms) will provide relevant in vivo and vitro testing and new therapeutic strategies for antiepileptic drug hypersensitivity.

Keyword

Anticonvulsants; Drug hypersensitivity; Severe cutaneous adverse reactions; Pharmacogenetics; Risk factors