Mammalian toxicology of organophosphorus pesticides

J Toxicol Environ Health. 1994 Nov;43(3):271-89. doi: 10.1080/15287399409531921.


Organophosphorus compounds have been utilized as pesticides for almost five decades. They continue to be used as insecticides, helminthicides, ascaricides, nematocides, and to a lesser degree as fungicides and herbicides. While they have been and continue to be extremely useful in agricultural pest control throughout the world, their extensive use has led to numerous poisonings of nontarget species, including many human fatalities. The primary acute mammalian toxicity associated with exposure to organophosphorus pesticides results from inhibition of the enzyme acetylcholinesterase. However, other toxicities, some of which are life-threatening but not related to acetylcholinesterase inhibition, have been observed following exposure to certain organophosphorus compounds. The focus of the current review is to summarize the known effects, both cholinergic and noncholinergic, of organophosphorus pesticides in mammals. Included in this summary is a discussion of the metabolic activation of organophosphorus pesticides, since this process plays a critical role in mediating the acute toxicities of many of these pesticides.

Publication types

  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Animals
  • Ataxia / chemically induced
  • Cholinesterase Inhibitors / chemistry
  • Cholinesterase Inhibitors / pharmacokinetics
  • Cholinesterase Inhibitors / toxicity*
  • Cytochrome P-450 Enzyme System / metabolism
  • Drug Tolerance
  • Humans
  • Insecticides / chemistry
  • Insecticides / pharmacokinetics
  • Insecticides / toxicity*
  • Liver / enzymology
  • Liver / metabolism
  • Neoplasms / chemically induced
  • Organophosphorus Compounds*
  • Oxygenases / metabolism
  • Receptors, Cholinergic / drug effects


  • Cholinesterase Inhibitors
  • Insecticides
  • Organophosphorus Compounds
  • Receptors, Cholinergic
  • Cytochrome P-450 Enzyme System
  • Oxygenases
  • dimethylaniline monooxygenase (N-oxide forming)