Short-term impact of the switch from immediate-release to extended-release oxcarbazepine in epilepsy patients on high dosages.
Extended-release oxcarbazepine (OXC) was introduced in Germany in January of 2008. In principle, this formulation should allow a better tolerability due to the less marked serum peak concentration of OXC prior to metabolization to its monohydroxy derivate (MHD) that is the active compound. Twenty-seven in-patients who had been referred to our epilepsy centre because of their difficult-to-treat localization-related epilepsies and had been on immediate-release OXC were abruptly switched to extended-release OXC at identical dosages. The adverse event profile (AEP) and the QOLIE-10 questionnaire were obtained immediately prior to and 5 days after this switch. On both days MHD fasting serum concentrations were also measured. After the switch a significant improvement of tolerability and quality of life was reported according to AEP and QOLIE-10 (p<0.001). Ameliorations were apparent in almost every patient (AEP: 26 of 27 patients, QOLIE-10: 23 of 27 patients). The improvement not explained by a drop of MHD levels. On the contrary and in line with preclinical data, serum levels of MHD rose significantly (p<0.001). We suggest that patients on extended-release OXC experience a lower serum concentration peak of the pro-drug OXC.
Steinhoff
Bernhard J
BJ
Epilepsy Center Kork, Kehl-Kork, Germany. bsteinoff@epilepsiezentrum.de
Wendling
Anne-Sophie
AS
D000328:Adult; D000368:Aged; D000927:Anticonvulsants / Q000008:administration & dosage / Q000009:adverse effects / Q000097:blood; D002220:Carbamazepine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000097:blood; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004828:Epilepsies, Partial / Q000097:blood / Q000188:drug therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D016896:Treatment Outcome
D000927:Anticonvulsants; D003692:Delayed-Action Preparations; C476610:oxcarbamazepine; D002220:Carbamazepine