Management overview for organophosphate and carbamate poisonings

Organophosphate and carbamate compounds include a large number of pesticides (including insecticides) used in agriculture. They inhibit cholinesterase enzyme activity and increase acetylcholine in the body. Properties and effects of organophosphate and carbamate pesticides lists the common organophosphate and carbamate pesticides available in Australia. Some organophosphate insecticides are prepared in hydrocarbon solvents that carry other potential toxicity—see also the Hydrocarbon ingestion monograph.

Organophosphate and carbamate poisonings are uncommon and have a wide and variable range of toxicities. The clinical presentation most commonly includes an acute cholinergic crisis and central nervous system (CNS) effects. Carbamates are less toxic than organophosphates and have a shorter duration of toxicity. Dermal and inhalational exposures are much more common than ingestions. These exposures can cause mild systemic symptoms, but rarely cause severe poisoning.

If organophosphate or carbamate poisoning is suspected, urgently contact a clinical toxicologist or poisons information centre (13 11 26). Management of organophosphate poisoning includes resuscitation and antidotal therapy with atropine. The use of pralidoxime is controversial. Management of carbamate poisoning is similar to organophosphate poisoning, involving resuscitation and atropine administration.

Chemical, biological and radiation precautions are not required for organophosphate and carbamate poisonings. Universal precautions (gloves, gowns, eye protection) are sufficient to ensure staff safety.