AChE inhibitors toxicity

Even though all OP insecticides have a common mechanism of action, differences occur among individual compounds. OP insecticides can be grouped into direct and indirect ACHE inhibitors. Direct inhibitors are effective without any metabolic modification, while indirect inhibitors require biotransformation to be effective. Moreover, some OP pesticides inhibit ACHE more than PCHE, while others do the opposite. For example, malathion, diazinon, and dichlorvos are earlier inhibitors of PCHE than of ACHE. In these cases, PCHE is a more sensitive indicator of exposure, even though it is not correlated with symptoms or signs of toxicity. 

Over the past decade, several reversible centrally acting AChE inhibitors including donepezil, rivastigmine, metrifonate, galanthamine, and huperzine A (HUP) were developed for the treatment of Alzheimer s disease. These inhibitors have great potential as pretreatments and treatments to counteract the toxicity of OP nerve agents. The efficacy of various pretreatments such as... 

Chronic toxicity of AChE inhibitors peripheral nerve demyelination with both muscle weak- ness and sensory loss... 

Long-acting AChE inhibitors are commonly used as insecticides. Whereas these are less toxic for humans, they still provide a hazard, causing poisoning with both acute and chronic symptoms caused by both muscarinic and nicotinic hyperactivity ("dumbbelss"). 

Drug interactions hyperkalemia enhances effects and vice versa displaces digoxin from tissue binding sites, enhancing toxicity may oppose effects of AChE inhibitors in myasthenia. 

Tritolyl phosphate, TCP. Mixture of isomers that have varying potencies as AChE inhibitors and inducers of delayed polyneuropathy. LindoT is the trade name for a mixture of isomers with a reduced content of the most toxic form, TOCP qv. Use now largely restricted to use as an additive to lubricants, specialist fuels and hydraulic fluids. 

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