RESUMO
During pregnancy, there are several physiological changes that influence the kinetics of medication administrated during this time. These physiological changes are not reestablished immediately during delivery; so, its concentration in biologic fluids is different when is administered immediately after delivery, than several weeks after. The purpose in this work was to identify the changes of pharmacocinetics constants for fenitoin and carbamacepine, in epileptic patients. When the same dose is maintained, during different times of postpartum. In 20 Mexican epileptic women, the plasma and milk concentrations of fenitoina during 60 day postpartum and in 14 carbamacepine was determined. In all the patients pharmakocinetics of anticonvulsivant, in each study period (5, 15, 30, 45 y 60 days postpartum). Excretion index of maternal milk was determined. Maximal plasmatic concentration of fentoine had no variation; however, carbamacepine was higher during the late period. There were no differences in the areas under curve and life all the middle of elimination and in excretion index.
Assuntos
Anticonvulsivantes/farmacocinética , Carbamazepina/farmacocinética , Epilepsia/tratamento farmacológico , Fenitoína/farmacocinética , Período Pós-Parto , Complicações na Gravidez/tratamento farmacológico , Animais , Cricetinae , Feminino , Humanos , Leite Humano/química , GravidezRESUMO
Durante el embarazo existen una serie de cambios fisiológicos que influyen en la cinética de los medicamentos administrativos durante esta etapa: Estos cambios fisiológicos no se restauran inmediatamente en el parto, de tal manera que su concentración en los fluidos biológicos es diferente cuando se administra inmediatamente después del parto que varias semanas posterior al mismo. El presente trabajo tiene como propósito identificar los cambios en las constantes farmacocinéticas de fenitoína y carbamacepina, en pacientes epilépticas cuando se mantiene una misma dosis durante diferentes etapas del postparto. En 20 mujeres mexicanas epilépticas se determinó la concentración en plasma y leche de fenitoína durante 60 días postparto y en 14 se determinó carbamacepina. A todas las pacientes se les realizó la farmacocinética de los anticonvulsivantes en cada periodo de estudio (5, 15, 30, 45 y 60 días posparto) y se determinó el índice de excreción en leche materna. Las concentraciones plasmáticas de fenitoína no presentaron variaciones, sin embargo la carbanacepina fue más alta en el periodo tardió, también se observaron diferencias en las áreas bajo la curva y vida media de eliminación y en los índices de excreción
Assuntos
Humanos , Feminino , Carbamazepina/farmacocinética , Epilepsia/tratamento farmacológico , Fenitoína/farmacocinética , Lactação/efeitos dos fármacos , Leite Humano/efeitos dos fármacos , Período Pós-Parto/efeitos dos fármacosRESUMO
Phenytoin serum concentrations were evaluated in 88 epileptic women at different stages of pregnancy and 40 women during postnatal periods. In addition, concentrations were determined from the umbilical cords of 27 neonates. On average, the dose of phenytoin was increased by 130 +/- 54 mg in 67% of the patients in order to control seizures. In 76% of the women during pregnancy and 95% in the postnatal periods, dose adjustment was achieved for the control of the seizures. Therapeutic clinical concentrations ( < 9.9 micrograms/ml) were found in 64% of the patients, with an average of 7.2 +/- 1.8 micrograms/ml during pregnancy and 6.2 +/- 2 micrograms/ml in 90% of the women during the postnatal period. The average phenytoin concentration reached with doses of 100, 200, 300, 400 and 500 mg were 3.3, 5.7, 8.4, 10.8, and 14.1 microliters/ml, respectively, without statistically significant differences among the pharmacokinetic parameters measured during pregnancy, between pregnancy and the postnatal period. The proportion between fetal and maternal phenytoin concentration was 0.37 +/- 0.28. Hydantoin fetal syndrome was seen in 8% of the neonates, without a statistically significant difference among patients with or without seizures. No relation was found between the concentration of phenytoin during pregnancy and the hydantoin fetal syndrome. The study shows that low concentrations of phenytoin can control seizures during pregnancy and the postnatal period and the need to relate serum phenytoin concentrations with the clinical state of pregnant women who suffer seizures.
Assuntos
Epilepsia/sangue , Fenitoína/sangue , Período Pós-Parto/sangue , Complicações na Gravidez/sangue , Adolescente , Adulto , Feminino , Humanos , Masculino , GravidezRESUMO
From a group of 50 premature newborns with central and mixed apnea, 34 received a loading dose of 4.3 mg/kg intravenous theophylline (group I) and 16 received 6 mg/kg orally (group II); the maintenance dose was 0.86 and 1 mg/kg every eight hours, respectively. Mean maximum serum concentrations after the loading dose were 5.8 +/- 2.3 mcg/mL in 25 newborns from group I, and 6.6 +/- 1,3 mcg/mL in 8 newborns from group II (P less than 0.20). Mean maximum concentration after the fifth maintenance dose was 7.5 +/- 1.7 mcg/mL in 26 newborns from group I, and 5.8 +/- 1.4 mcg/mL in 16 newborns from group II (P = 0.001); mean minimum concentration was 5.3 +/- 1.6 mcg/mL and 4.5 +/- 1.4 mcg/mL, respectively (P greater than 0.10). Mean clearance was 30.21 +/- 11.03 and 27.1 +/- 7.7 mL/kg/h; mean apparent distribution volume was 0.5 +/- 0.25 and 0.76 +/- 0.32 L/kg; elimination rate constant was 0.049 +/- 0.04 and 0.040 +/- 0.03/h-1 for both groups respectively, with significant differences between groups only in the apparent distribution volume (P less than 0.001). Half-life time (T1/2) was from four to 118 hours. The study population was divided into three groups according to half-life time: those with a half-life time of lesser than 20 hours (47.6%); an intermediate half-life time of from 20 to 30 hours (23.8%); and a long half-life time of more than 31 hours (28.6%).(ABSTRACT TRUNCATED AT 250 WORDS)