Oximes as pretreatment before acute exposure to paraoxon

Dietrich E. Lorke, Syed M. Nurulain, Mohamed Y. Hasan, Kamil Kuča, Georg A. Petroianu

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)


Organophosphates, useful agents as pesticides, also represent a serious danger due to their high acute toxicity. There is indication that oximes, when administered before organophosphate exposure, can protect from these toxic effects. We have tested at equitoxic dosage (25% of LD01) the prophylactic efficacy of five experimental (K-48, K-53, K-74, K-75, K-203) and two established oximes (pralidoxime and obidoxime) to protect from mortality induced by the organophosphate paraoxon. Mortalities were quantified by Cox analysis and compared with those observed after pretreatment with a strong acetylcholinesterase inhibitor (10-methylacridine) and after the FDA-approved pretreatment compound pyridostigmine. All nine tested substances statistically significantly reduced paraoxon-induced mortality. Best protection was conferred by the experimental oxime K-48, reducing the relative risk of death (RR) to 0.10, which was statistically significantly superior to pyridostigmine (RR = 0.31). The other oximes reduced the RR to 0.13 (obidoxime), 0.20 (K-203), 0.21 (K-74), 0.24 (K-75) and 0.26 (pralidoxime), which were significantly more efficacious than 10-methylacridine (RR = 0.65). These data support the hypothesis that protective efficacy is not primarily due to cholinesterase inhibition and indicate that the tested experimental oximes may be considered promising alternatives to the established pretreatment compound pyridostigmine.

Original languageEnglish
Pages (from-to)1506-1515
Number of pages10
JournalJournal of Applied Toxicology
Issue number11
Publication statusPublished - Nov 1 2019


  • Cox analysis
  • carbamates
  • cholinesterase
  • organophosphate
  • oximes
  • paraoxon
  • pretreatment
  • prophylaxis
  • rat

ASJC Scopus subject areas

  • Toxicology


Dive into the research topics of 'Oximes as pretreatment before acute exposure to paraoxon'. Together they form a unique fingerprint.

Cite this