title: Pharmacokinetics and efficacies of obidoxime and atropine in paraoxon poisoning.
abstract: 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.
authors.affiliation: Fraunhofer Institute for Environmental Chemistry and Ecotoxicology Grafschaft, Schmallenberg, Federal Republic of Germany.
authors.forename: K
authors.initials: K
authors.lastname: Schoene
authors.forename: A
authors.initials: A
authors.lastname: König
authors.forename: H
authors.initials: H
authors.lastname: Oldiges
authors.forename: M
authors.initials: M
authors.lastname: Krügel
mesh_terms: D000818:Animals; D000931:Antidotes; D001285:Atropine / Q000493:pharmacokinetics / Q000627:therapeutic use*; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006207:Half-Life; D007275:Injections, Intravenous; D007928:Lethal Dose 50; D051379:Mice; D009768:Obidoxime Chloride / Q000493:pharmacokinetics / Q000627:therapeutic use*; D010091:Oximes / Q000627:therapeutic use*; D010261:Paraoxon / Q000506:poisoning*
chemical_list: D000931:Antidotes; D010091:Oximes; D009768:Obidoxime Chloride; D001285:Atropine; D010261:Paraoxon