abstract

• Therapeutic drug monitoring (TDM) is routinely performed for drugs exhibiting a narrow therapeutic range, such as antiepileptics. Oxcarbazepine is a recently introduced anticonvulsant agent which dosing is currently adjusted on the basis of TDM of the plasma levels of its monohydroxy derivative (MHD), which is the active metabolite. This work describes our experience in MHD monitoring in an open Mexican population (n=161) of epileptic patients treated with oxcarbazepine. MHD measurements were carried out with an improved HPLC assay, which only requires 100 μL of plasma and is carried out in less than 3 min. As expected, MHD steady-state plasma concentrations were related to the daily dose, but a considerable amount of inter-individual variability remained unexplained. Demographic factors, such as age and gender, were detected as important sources of variability. Elderly patients exhibited higher MHD levels than young adults. On the other hand, female patients exhibited lower MHD concentrations than males. Concomitant medication also appeared to alter plasma levels of MHD. Finally, MHD plasma levels in about two thirds of the studied patients were not in the recommended range. It is therefore necessary to continue to evaluate the impact of covariates influencing MHD pharmacokinetics in order to improve oxcarbazepine dosing.

authors

• Aguirre Bañuelos Patricia
• Castañeda-Hernández G.
• Flores-Murrieta F.J.
• Pérez-Urizar J.

publication date

• 1999-01-01

published in

• Proceedings of the Western Pharmacology Society  Journal

start page

• 143

end page

volume

• 42