Study of the level/dose index of phenytoin in volunteer epileptic patients from Mérida

Introduction: Phenytoin is used very frequently in our environment, so it is necessary to do studies of therapeutic monitoring, which helps to minimize adverse drug reaction and optimize pharmacological therapy. In this context, our objective was to determine the level/dose index of phenytoin in volunteer epileptic patients from Mérida. Methods: A descriptive, observational and consecutive concurrent recruitment study was carried out, consisting of 30 volunteer patients with a diagnosis of epilepsy. The serum samples were obtained in minimum levels from patients who were in treatment with phenytoin for 1 month. The levels of the drug were quantified by the method of donor enzyme immunoassay cloned in the Indiko Thermo Scientific equipment. Results: The level/dose index was 1,4 and 1,6, the plasma concentration of 4,8 mg/l and 8,0 mg/l, the metabolic capacity of 388,4 and 462,9 mg/day, respectively in women and men. While the level of plasma concentration at steady state was 6,5 mg/l and 5,5 mg/l, the maximum loading dose of 237,3 mg and 395,6 mg, respectively in women and men with epilepsy of the city of Mérida. Conclusions: Our results suggest that the dose should be individualized based on the level/dose index of each patient, since it can not be extrapolated for all patients with epilepsy, due to various factors such as the metabolic phenotype and the use of enzyme-inducing drugs and inhibitors.