Organophosphate poisoning

Organophosphate poisoning can occur due to occupational or accidental exposure, deliberate ingestion, or chemical warfare with nerve gases.

Presentation is highly variable due to differences in dose, agent toxicity, and type of exposure.

Diagnosis is usually based on a history of exposure, with characteristic signs of cholinergic excess, but can be difficult when the patient is inadvertently exposed, unconscious, or confused.

Standard treatment is resuscitation, supportive care, decontamination, and use of atropine.

Accidental or occupational exposures nearly always have a favorable outcome.

This topic covers organophosphate poisoning in adults.

Organophosphate poisoning occurs after dermal, respiratory, or oral exposure to either organophosphate pesticides (e.g., chlorpyrifos, dimethoate, malathion, parathion) or nerve agents (e.g., tabun, sarin), causing inhibition of acetylcholinesterase at nerve synapses. Presentation is highly variable due to differences in dose, agent toxicity, and type of exposure. Symptoms of organophosphate poisoning include excessive secretions, fasciculations, bronchospasm, bradycardia, diarrhea, and pinpoint pupils; severe poisoning may present with seizures or respiratory failure, which may be fatal. The term organophosphate poisoning only applies to those organophosphates that inhibit acetylcholinesterase. This topic focuses on pesticide poisoning.