Organophosphate Poisoning

Organophosphate poisoning results from exposure to organophosphate pesticides, which are widely used in agriculture. These chemicals inhibit an enzyme (cholinesterase) needed for normal nerve function, and poisoning is a medical emergency.

• Excessive salivation, sweating, and tearing
• Nausea, vomiting, abdominal cramps, and diarrhoea
• Pinpoint pupils (miosis)
• Muscle twitching or weakness
• Excessive respiratory secretions, wheeze, and difficulty breathing
• In severe poisoning: confusion, seizures, and respiratory failure

• Occupational or accidental exposure while handling or spraying agricultural pesticides.
• Ingestion, whether accidental or intentional (self-poisoning), of organophosphate-containing products.
• Skin or inhalational exposure from contaminated clothing, spray drift, or improperly stored chemicals.

• Primarily a clinical diagnosis, based on history of exposure together with the characteristic combination of excess secretions, pinpoint pupils, and muscle weakness.
• Cholinesterase activity testing, where available, can support diagnosis and help gauge severity.
• It is important to identify the specific agent and route of exposure where possible.

This is a medical emergency requiring hospital-level care. Immediate priorities are removing contaminated clothing, washing exposed skin, and protecting healthcare workers from secondary contamination.

Atropine is given intravenously and titrated to dry secretions and improve breathing, often requiring large and repeated doses in severe poisoning.

Pralidoxime may be given alongside atropine, particularly if started early, to help reactivate the affected enzyme.

Supportive care includes airway management, oxygen, and monitoring for respiratory failure, which is the main cause of death and may require assisted ventilation.

Any suspected organophosphate poisoning should be referred urgently to a facility capable of providing this level of monitoring and care.

• Use protective clothing and equipment when handling pesticides.
• Store pesticides in original, clearly labelled containers, out of reach of children.
• Follow safe application practices and avoid spraying in windy conditions.
• Wash hands and change clothing promptly after exposure.
• Seek support services for anyone at risk of intentional self-poisoning.