Cutaneous reactions induced by oxcarbazepine in Southern Han Chinese: incidence, features, risk factors and relation to HLA-B alleles.

Purpose: Oxcarbazepine (OXC) is a promising alternative for patients who cannot tolerate carbamazepine. Recently, however, it has been reported that OXC-induced cutaneous adverse drug reactions (cADRs) are prevalent and may lead to drug discontinuation. Additionally, these reactions are thought to be associated with HLA-B*1502. This study aims to investigate the incidence, features and risk factors of OXC-cADRs, and to explore their relation to HLA-B alleles in Southern Han Chinese.

Methods: A prospective study was performed to investigate the incidence, features and risk factors of OXC-cADRs, in which 252 new users were recruited. To examine the association between OXC-cADRs and HLA-B alleles, 14 maculopapular eruption (MPE) cases, including 9 additional cases beyond this prospective observation, were genotyped by PCR-SSP and sequencing. Thirty-five OXC-tolerant patients served as controls.

Results: Five patients (2.0%) developed an OXC-cADR, and all were mild MPE. History of other AED allergy (p=0.005, OR=121.23) and non-AED allergy (p=0.006, OR=59.92) were significant risk factors for OXC-cADRs in multivariate logistic regression analysis. Only one patient with OXC-MPE was positive for HLA-B*1502; and the frequency of HLA-B*1502 in OXC-MPE did not differ significantly from that in OXC-tolerant controls. Four HLA-B*1302 alleles were detected in OXC-MPE cases, which was significantly different from that in general population of southern Han Chinese (p=0.001, OR=7.83).

Conclusions: The incidence of OXC-induced cADRs was low, and no severe reactions occurred. Patients with a history of allergy are more susceptible to OXC-cADRs. No significant association between HLA-B*1502 and OXC-MPE was found. The associations between OXC-MPE and HLA alleles warrant further studies.