Plasma level monitoring of oxcarbazepine in epileptic patients

Background. Despite the wide use of oxcarbazepine (OXC) there is little dat a concerning the usefulness of plasma level monitoring with this drug in Me xican patients with epilepsy. The purpose of the present study was to deter mine whether OXC levels correlate with dose, age, weight, or drugs used con comitantly. Methods. Plasma levels of the antiepileptic drug OXC were evaluated ill 214 patients with epilepsy. In each patient, plasma MHD (10-hydroxycarbazepine , the main metabolite of OXC) concentration was determined. Additionally, p lasma protein binding was determined in 30 patients and affinity to red blo od cells (RBCs) was evaluated in 50 patients. Results. Our results showed that the mean plasma level of MHD was 15.34 mu g/mL, mean protein binding ranged between 30-40%, and the mean RBC concentr ation was 18.38 mu g/mL. A relationship between dose/weight and plasma conc entration was found (r = 0.5149, p <0.001). In addition, a linear relations hip between plasma and RBC concentration was established (r = 0.8806, p <0. 0001). Conclusion. These results suggest that for OXC, routine RBC concentrations are not necessary to make drug adjustments. (C) 2000 IMSS. Published by Els evier Science Inc.