Monitorización terapéutica de niveles séricos de antiepilépticos en Atención Primaria

Therapeutic monitoring of serum levels is a usual clinical procedure that may help to achieve the rational use of antiepileptics. This article describes their background, basis and utility. The reference clinical guidelines or necessary requirements to use monitoring appropriately are reviewed and up-dated. These guidelines include presently recognized indications to measure total and free concentrations as well as active metabolite ones, appropriateness of the sampling time, type of sample used and requirements for analytic accuracy. Some aspects on the clinical pharmacokinetics of the antiepileptics (absorption, distribution and elimination) and factors that modify this pharmacokinetics and the relationship between dose and serum concentration, type of kinetics, concentration/dose ratios and therapeutic ranges are also mentioned.