Chlorpyrifos Poisoning Treatment Guidelines

Pathophysiology and Toxicity

• Chlorpyrifos causes irreversible acetylcholinesterase inhibition leading to acetylcholine accumulation and cholinergic syndrome, with toxicity extending beyond simple cholinesterase inhibition to include neuroinflammation and disruption of multiple neurotransmitter systems 1
• Acetylcholinesterase inhibition is uninformative regarding neurodevelopmental effects, as toxic effects from chronic low-level exposure occur at concentrations too low to inhibit cholinesterase 2

Neurodevelopmental and Neurological Effects

• Chlorpyrifos can cause delayed myelopathy and pure motor neuropathy appearing 6-8 weeks after initial recovery from cholinergic crisis, resulting in permanent paralysis at sites of dermal exposure, particularly affecting hands and feet with atrophy and loss of function 1