Hyponatremia Associated with Oxcarbazepine: Cross-Sectional Study

B a c k g r o u n d : Renewed attention was focused on hyponatremia when oxcarbazepine (OXC) was introduced. Although OXC-induced hyponatremia is usually asymptomatic, it can lead to serious complications. We estimated the frequency of hyponatremia in patients treated with OXC and investigated its risk factor in the Korean population. M e t h o d s : A cross-sectional study was carried out in 59 patients receiving OXC and 71 patients receiving carbamazepine (CBZ). Hyponatremia was defined as serum sodium levels less than 135 mEq/L. Data from our patients were examined to ascertain the characteristics of OXC-induced hyponatremia. Results : In the Korean population, the fre quency of OXC-induced hyponatremia was 15% (9 out of 59) including 2 symptomatic patients compared to 7% (5 out of 71) without symptomatic cases in CBZ treated patients. The mean serum sodium level in OXC-treated patients was significantly lower than that in CBZ-treated patients. Sex was significantly related to serum sodium levels in both OXCand CBZ-treated patients. OXC-induced hyponatremia was more frequently observed in females. Age, dosage, and polytherapy were probably not predisposing risk factors in both OXC- and CBZ-induced hyponatremia. Conclusions : In the Korean population, the prevalence of both OXC- and CBZ-induced hyponatremia seems to be lower than those in other countries. However, the symptomatic cases of OXC-induced hyponatremia are not rare compared to those in for eign countries. We therefore, strongly encourage the monitoring of sodium levels during OXC therapy especially in female patients. J Korean Neurol Assoc 19(2):139~142, 2001