Plasma level monitoring of oxcarbazepine in epileptic patients.
BACKGROUND
Despite the wide use of oxcarbazepine (OXC) there is little data concerning the usefulness of plasma level monitoring with this drug in Mexican patients with epilepsy. The purpose of the present study was to determine whether OXC levels correlate with dose, age, weight, or drugs used concomitantly.


METHODS
Plasma levels of the antiepileptic drug OXC were evaluated in 214 patients with epilepsy. In each patient, plasma MHD (10-hydroxycarbazepine, the main metabolite of OXC) concentration was determined. Additionally, plasma protein binding was determined in 30 patients and affinity to red blood cells (RBCs) was evaluated in 50 patients.


RESULTS
Our results showed that the mean plasma level of MHD was 15.34 microg/mL, mean protein binding ranged between 30-40%, and the mean RBC concentration was 18.38 microg/mL. A relationship between dose/weight and plasma concentration was found (r = 0.5149, p <0.001). In addition, a linear relationship between plasma and RBC concentration was established (r = 0.8806, p <0.0001).


CONCLUSIONS
These results suggest that for OXC, routine RBC concentrations are not necessary to make drug adjustments.
González-Esquivel
D F
DF
Laboratorio de Neuropsicofarmacología, Instituto Nacional de Neurología y Neurocirugía, México, D.F., Mexico. dinofab@hotmail.com
Ortega-Gavilán
M
M
Alcántara-López
G
G
Jung-Cook
H
H
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000927:Anticonvulsants / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics / Q000494:pharmacology; D001798:Blood Proteins / Q000378:metabolism; D001835:Body Weight; D002220:Carbamazepine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D002648:Child; D002675:Child, Preschool; D004347:Drug Interactions; D016903:Drug Monitoring; D004359:Drug Therapy, Combination; D004827:Epilepsy / Q000097:blood / Q000188:drug therapy*; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D000078330:Oxcarbazepine; D011485:Protein Binding
D000927:Anticonvulsants; D001798:Blood Proteins; D002220:Carbamazepine; D000078330:Oxcarbazepine