Organophosphate poisoning and carbamate poisoning

[Marquetta]

Organophosphates and carbamates are common insecticides that inhibit cholinesterase activity, causing acute muscarinic manifestations (eg, salivation, lacrimation, urination, diarrhea, emesis, bronchorrhea, bronchospasm, bradycardia, miosis) and some nicotinic symptoms, including muscle fasciculations and weakness. Neuropathy can develop days to weeks after exposure. Diagnosis is clinical and sometimes with a trial of atropine , measurement of red blood cell acetylcholinesterase level, or both. Bronchorrhea and bronchospasm are treated with titrated high-dose atropine . Neuromuscular toxicity is treated with IV pralidoxime .
(See also General Principles of Poisoning.)
Organophosphates and carbamates, although different structurally, both inhibit cholinesterase activity. Some are used medically to reverse neuromuscular blockade (eg, neostigmine , pyridostigmine , edrophonium ) or to treat glaucoma (echothiopate), myasthenia gravis (pyridostigmine ), and Alzheimer disease (tacrine and donepezil ).
Some organophosphates were developed as nerve gases. One, sarin, has been used by terrorists. Organophosphates and carbamates are commonly used as insecticides (see table Symptoms and Treatment of Specific Poisons). Those most often implicated in human poisoning include

Carbamates: Aldicarb and methomyl
Organophosphates: Chlorpyrifos, diazinon, dursban, fenthion, malathion, and parathion

Organophosphates and carbamates are common causes of poisoning and poison-related deaths worldwide.