Plasma concentrations of pralidoxime methylsulphate in organophosphorus poisoned patients.

Abstract

Using pharmacokinetic data from healthy human volunteers in a bicompartmental pharmacokinetic model, a repeated dose scheme for pralidoxime methylsulphate (Contrathion) was developed producing plasma levels remaining above the assumed "therapeutic concentration" of 4 mg.l-1. Using the same data, it was found that a concentration of 4 mg.l-1 could also be obtained by a loading dose of 4.42 mg.kg-1 followed by a maintenance dose of 2.14 mg.kg-1.h-1. In order to study the pharmacokinetic behaviour of pralidoxime in poisoned patients, this continuous infusion scheme was then applied in nine cases of organophosphorus poisoning (agents: ethyl parathion, ethyl and methyl parathion, dimethoate and bromophos), and the pralidoxime plasma levels were determined. The mean plasma levels obtained in the various patients varied between 2.12 and 9 mg.l-1. Pharmacokinetic data were calculated, giving a total body clearance of 0.57 +/- 0.27 l.kg-1.h-1 (mean +/- SD), an elimination half-life of 3.44 +/- 0.90 h, and a volume of distribution of 2.77 +/- 1.45 l.kg-1.

• Authors: J L Willems, J P Langenberg, A G Verstraete, M De Loose, B Vanhaesebroeck, G Goethals, F M Belpaire, W A Buylaert, D Vogelaers, F Colardyn
• Journal: Archives of toxicology (Arch Toxicol) Vol. 66 Issue 4 Pg. 260-6 ( 1992) ISSN: 0340-5761 [Print] Germany
• PMID: 1514924 (Publication Type: Case Reports, Journal Article)

Chemical References

• Insecticides
• Organothiophosphorus Compounds
• Pralidoxime Compounds
• pralidoxime

Topics

• Dose-Response Relationship, Drug
• Female
• Humans
• Infusions, Intravenous
• Insecticides (poisoning)
• Male
• Organothiophosphorus Compounds
• Poisoning (drug therapy)
• Pralidoxime Compounds (blood, pharmacokinetics, therapeutic use)