ABSTRACT
In acute severe anticholinesterase poisoning by organophosphate compounds, pralidoxime (P-2-AM, pyridine-2-aldoxime methiodide) used in the recommended doses, intravenously, has not been shown to reactivate the inhibited cholinesterase, as evidenced both clinically and biochemically. In vitro studies using pralidoxime iodide up to ten times the recommended concentrations, produced insignificant reactivation of cholinesterases inhibited by the organophosphate insecticide Bidrin (di-methyl-3-hydroxyl-N, N-dimethyl-crotonamide phosphate). This was even so despite prolonged exposure of the inhibited cholinesterases to the oxime. The value of pralidoxime as a reactivator of phosphorylated cholinesterases is therefore in doubt, and should not be used in preference to large doses of atropine and other supportive treatment in poisoning by organophosphate insecticides.
Subject(s)
Acetylthiocholine , Atropine/therapeutic use , Butyrylthiocholine , Cholinesterase Inhibitors , Dose-Response Relationship, Drug , Enzyme Reactivators , Humans , Insecticides/poisoning , Malaysia , Organophosphorus Compounds , Pralidoxime Compounds/pharmacologyABSTRACT
There is biochemical and clinical evidence that P-2-AM (Pyridine-2-Aldoxime Methiodide, Pralidoxime) does not reactive human acetylcholinesterase inhibited by either Malathion or Malaoxon. In vitro studies using Pralidoxime iodide up to ten times the recommended concentrations, produced insignificant reactivation of cholinesterases inhibited by Malathion or Malaoxon. This was observed inspite of prolonged exposure of the inhibited cholinesterases to the oxime. The value of Pralidoxime as a reactivator of phosphorylated cholinesterases is therefore in doubt, and should not be used in preference to large doses of atropine and other supportive treatment in poisoning by organophosphate pesticides.