# Organophosphate Poisoning in Children

> Organophosphate poisoning in children for NEET-PG Paediatrics covering muscarinic features, atropine titration, pralidoxime and intermediate syndrome.

- Canonical URL: https://prepelephant.com/topics/neet-pg/paediatrics/organophosphate-poisoning-in-children
- Exam / course: NEET-PG · Subject: Paediatrics
- Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team
- First published: 2026-10-14
- Last updated: 2026-10-14
- Reference basis: Nelson Textbook of Pediatrics; Goldfrank's Toxicologic Emergencies
- How to cite: "Organophosphate Poisoning in Children", PrepElephant, https://prepelephant.com/topics/neet-pg/paediatrics/organophosphate-poisoning-in-children

## Direct answer

Organophosphate poisoning in children occurs when the compound phosphorylates acetylcholinesterase, so acetylcholine builds up at muscarinic and nicotinic sites. Atropine blocks the muscarinic effects and is titrated to dry the chest and restore heart rate, while pralidoxime reactivates the enzyme if given before it ages. Monocrotophos, chlorpyrifos and dichlorvos are common culprits in India.

## What you must remember

- **Mechanism:** Phosphorylation of acetylcholinesterase, which leads to acetylcholine excess at synapses.
- **Muscarinic features:** Salivation, lacrimation, urination, diarrhoea, vomiting, bronchorrhoea, bradycardia and miosis, summarised as SLUDGE or DUMBELS.
- **Nicotinic features:** Fasciculations, generalised weakness, tachycardia, hypertension and respiratory muscle paralysis.
- **Atropine:** Titrated to clear bronchial secretions and restore heart rate; pupil size is an unreliable endpoint.
- **Pralidoxime:** Reactivates the phosphorylated enzyme only before ageing, and has no role in carbamate poisoning.
- **Intermediate syndrome:** Proximal limb, neck and respiratory muscle weakness about 24 to 96 hours after poisoning.
- **Delayed neuropathy:** Distal weakness appearing around 2 to 3 weeks after exposure.
- **Decontamination:** Remove contaminated clothes and wash the skin, protecting the rescuer from contact exposure.

## A stepwise approach to acute management

Organophosphate care is driven by airway control and atropine titration, not by any single drug. The steps below follow standard toxicology teaching for a child with cholinergic crisis.

1. **Protect yourself and decontaminate:** Remove contaminated clothing and wash the skin with soap and water, since rescuers can be poisoned by contact.
2. **Secure the airway:** Suction bronchorrhoea and intubate early for coma, respiratory depression or muscle paralysis.
3. **Give atropine:** Give weight-based intravenous doses and repeat them until the chest is clear and heart rate is normal. Watch for atropine toxicity, such as agitation, hyperthermia and tachycardia.
4. **Add pralidoxime:** Give it early, as its benefit falls with ageing of the enzyme. It does not help when the poison is a carbamate.
5. **Control seizures and monitor:** Treat seizures with standard anticonvulsants and watch for intermediate syndrome over the following days.
6. **Plan follow-up:** Warn of delayed neuropathy and assess for self-harm, since pesticide ingestion in adolescents is often intentional.

## Where the exam tries to catch you

Organophosphate questions often test the atropine endpoint and the difference between carbamate and organophosphate poisoning.

- **Trap:** Titrating atropine to pupil size. — **Correct:** Titrate to bronchial secretions and heart rate, because miosis can persist even when treatment is adequate.
- **Trap:** Giving pralidoxime for a carbamate ingestion. — **Correct:** Carbamates are reversible inhibitors, so pralidoxime is not indicated and atropine remains the main treatment.
- **Trap:** Expecting recovery once the acute crisis settles. — **Correct:** Intermediate syndrome and delayed neuropathy follow, so the child needs prolonged observation.
- **Trap:** Treating diarrhoea, vomiting and bradycardia as gastroenteritis. — **Correct:** Together with miosis, these point to cholinergic toxicity, so ask about pesticides at home.

## Frequently asked questions

### What are the muscarinic features of organophosphate poisoning in children?

Muscarinic features of organophosphate poisoning in children are excess salivation, lacrimation, urination, diarrhoea, vomiting, bronchorrhoea, bradycardia and miosis. They are summarised by the mnemonic SLUDGE or DUMBELS. Bronchorrhoea is usually the most dangerous feature because it impairs breathing.

### What is the role of pralidoxime in organophosphate poisoning?

Pralidoxime reactivates acetylcholinesterase that an organophosphate has phosphorylated, and it works best when given early. It has no value once the enzyme has aged, and it does not help carbamate poisoning. Pralidoxime is therefore given alongside atropine, not instead of it.

### What is intermediate syndrome after organophosphate poisoning?

Intermediate syndrome is proximal limb, neck and respiratory muscle weakness that appears about 24 to 96 hours after organophosphate poisoning. It needs ventilatory support in severe cases. It is distinct from the distal delayed neuropathy that appears weeks later.

### Why is atropine titrated to chest secretions rather than pupil size?

Atropine is titrated to clear bronchial secretions and restore heart rate because these are the clinically important muscarinic effects. Miosis can persist even when treatment is adequate, so pupil size is an unreliable endpoint. Excess atropine causes agitation, hyperthermia and tachycardia, which are signs of overdose.