RESUMEN
The efficacies (ED50) of obidoxime and atropine against paraoxon poisoning in mice were determined by administering the antidotes 5, 20, 40 and 60 min before administration of the organophosphate. With increasing time intervals t between the administration of the antidote and paraoxon, the dose of antidote (ED50), that reduced the lethality of 2 LD50 of paraoxon to 50% increased. The standardized log ED50/t plot was linear and yielded the "efficacy half-life". In addition, the blood concentrations c of the antidotes were measured, resulting in a linear log c/t plot. The "efficacy half-life" was approximately twice the half-life of the antidote in blood. The possible reasons for this phenomenon are discussed.
Asunto(s)
Antídotos , Atropina/uso terapéutico , Cloruro de Obidoxima/uso terapéutico , Oximas/uso terapéutico , Paraoxon/envenenamiento , Animales , Atropina/farmacocinética , Cromatografía Líquida de Alta Presión , Femenino , Semivida , Inyecciones Intravenosas , Dosificación Letal Mediana , Ratones , Cloruro de Obidoxima/farmacocinéticaRESUMEN
The functional set-up of a static inhalation device is described. The closed system consists of a reservoir for the circulating test gas, an inhalator for "nose-only" exposure of 10 rats, and analyzers for the test gas and CO2. It has an overall volume of 200 liters. The following LCt50 values for rats exposed to noxious vapors were determined: DFP 3629, sarin 191, and soman 211 mg X min X m-3. Pretreatment with atropine (10 mg/kg) together with the oximes Toxogonin or HJ6 (each 13 mg/kg) 10 min before the exposure raised the LCt50 of sarin by a factor of 2.5 and 14, respectively. In case of soman poisoning, only HJ6 (50 mg/kg) together with atropine was effective, which increased the LCt50 by a factor of 7.