Organophosphate poisoning/intoxication cholinesterases

A classification of organophosphate poisoning has been proposed by Tafuri and Roberts (1987) modified from Namba et al. (1971). Clinical signs and symptoms of intoxication may occur when serum cholinesterase levels drop to below 50% of the normal value. Mild poisoning, with the patient still ambulatory, may occur when serum cholinesterase levels are 20-50% of normal moderate poisoning with inability to walk with levels 10-20% of normal and severe poisoning with respiratory distress and unconsciousness with serum cholinesterase levels <10% of normal. 

A. Oximes are used to treat poisoning caused by cholinesterase inhibitor insecticides and nerve agents, ie, organophosphates, mixtures of organophospho-ms and carbamate insecticides, or pure carbamate insecticide intoxication with nicotinic-associated symptoms. Because of its low toxicity, possible ineffectiveness if treatment is delayed until after the cholinesterase enzyme has aged, ability to reverse nicotinic as well as muscarinic effects, and ability to reduce atropine requirements, pralidoxime should be used early and empirically for suspected cholinesterase inhibitor poisoning. 

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