Pediatric Poisoning by Organophosphate and Carbamate-type Pesticides
With increasing restrictions on the sale and use of environmentally persistent organochlorine compounds, acetylcholinesterase-inhibiting agents (carbamates and organophosphates) rapidly have become the most widely used commercial and residential pesticides. Consequently, pediatricians are encountering children accidentally exposed to these potent neurotoxins by ingestion or by dermal absorption more frequently.
Organophosphates (eg, diazinon, malathion, mevinphos, bomyl, and methamidophos) avidly bind to cholinesterase, phosphorylating the enzyme at all postganglionic parasympathetic nerves, at myoneural junctions, at both parasympathetic and sympathetic ganglia, and within the central nervous system. As a result, the neurotransmitter acetylcholine, which cannot be inactivated by hydrolysis at these sites, accumulates. Excessive stimulation of peripheral muscarinic and nicotinic as well as central cholinergic neurons occurs.
