For chlorex organophaophours Atropine only or atropine and physostigmine needes
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The textbooks give a very clear answer. Here is the full explanation:
Organophosphorus (e.g., Chlorpyrifos) Poisoning - Treatment
Answer: Atropine + Pralidoxime (2-PAM) - NOT physostigmine
Physostigmine is explicitly contraindicated in organophosphorus poisoning.
Why NOT Physostigmine?
Physostigmine is itself a cholinesterase inhibitor - it works by blocking acetylcholinesterase (AChE). In organophosphate poisoning, AChE is already being poisoned/inhibited. Giving physostigmine would worsen the cholinergic crisis by further increasing acetylcholine accumulation at all synapses.
Physostigmine is used for the opposite situation - anticholinergic (atropine) overdose, where it helps reverse CNS effects.
The Essentials of Forensic Medicine explicitly states:
"Avoid physostigmine, edrophonium chloride, and succinylcholine."
Correct Treatment of Organophosphorus Poisoning
| Drug | Role | Mechanism |
|---|---|---|
| Atropine sulfate | Primary antidote | Muscarinic receptor antagonist - blocks the excess ACh at muscarinic receptors (reverses SLUDGE: salivation, lacrimation, urination, defecation, GI cramps, emesis + bronchospasm/bronchorrhea) |
| Pralidoxime (2-PAM) | Cholinesterase reactivator | Competes for the phosphate moiety, liberates the organophosphate from the AChE enzyme - must be given early before "ageing" (irreversible binding) occurs |
Atropine dosing:
- Initial: 2-4 mg IV (pediatric: 0.05 mg/kg)
- Double every 10-15 min if no response
- Continue until secretions dry and bronchospasm resolves
- Average ~40 mg/day; doses up to 1,000 mg/day have been used
- Endpoint = drying of secretions (NOT pupil size)
- Tachycardia is NOT a contraindication to atropine
Quick Memory Trick
| Situation | Drug |
|---|---|
| Organophosphate OD (too much ACh) | Atropine (blocks ACh) + Pralidoxime (frees AChE) |
| Atropine OD (anticholinergic crisis) | Physostigmine (inhibits AChE to increase ACh) |
The two are literally used for opposite toxidromes - physostigmine would be catastrophic in organophosphate poisoning.
- The Essentials of Forensic Medicine and Toxicology, 36th ed.
- Lippincott Illustrated Reviews: Pharmacology
Is atropin plus oxide I mean for clerk pirates first only atropin or both are
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Here is the clear, definitive answer:
Chlorpyrifos (Organophosphorus): Atropine Alone or Atropine + Oxime?
Answer: BOTH - Atropine + Pralidoxime (Oxime/2-PAM)
Why Both Are Needed - Simple Explanation
Organophosphate poisoning causes two types of effects simultaneously, and atropine alone cannot handle both:
| Effect | Site | Reversed by |
|---|---|---|
| Excessive secretions, bronchospasm, bradycardia, SLUDGE | Muscarinic receptors | ✅ Atropine |
| Muscle weakness, fasciculations, respiratory muscle paralysis | Nicotinic receptors (NMJ) | ❌ Atropine has NO effect here |
| CNS - confusion, seizures, coma | CNS | ✅ Atropine (partial) + Pralidoxime |
"Atropine is virtually without effect against the peripheral neuromuscular compromise, which can be reversed by pralidoxime (2-PAM), a cholinesterase reactivator."
- Goodman & Gilman's Pharmacology
How Pralidoxime (Oxime) Works
- It physically pulls the organophosphate off the AChE enzyme, reactivating it
- Must be given EARLY - before "ageing" (irreversible binding) occurs
- Dose: 1-2 g IV slowly in moderate/severe cases; repeat after 20-60 min if needed
Key Rule: Timing Matters for Pralidoxime
| Timing | Pralidoxime effectiveness |
|---|---|
| Given within 24-48 hours | Very effective |
| After ageing has occurred | Useless (irreversible bond formed) |
Atropine has no time limit - it can be given at any stage to control muscarinic symptoms.
Bottom Line
For chlorpyrifos / any organophosphorus poisoning:
-
✅ Atropine - always, for muscarinic effects
-
✅ Pralidoxime (2-PAM / oxime) - always add this, especially if given early, for nicotinic/NMJ effects
-
❌ Physostigmine - absolutely contraindicated
-
Goodman & Gilman's Pharmacological Basis of Therapeutics
-
The Essentials of Forensic Medicine and Toxicology, 36th ed.
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