Which of the following is an antidote for organophosphorus poisoning?

Appeared in: UPPSC 2023

Explanation

Organophosphorus (OP) compounds cause poisoning by inactivating the acetylcholinesterase enzyme, leading to an excess of acetylcholine.
This excess acetylcholine results in a cholinergic crisis, with symptoms remembered by the mnemonic DUMBELS (Diarrhea, Urination, Miosis, Bradycardia/Bronchorrhea, Emesis, Lacrimation, Salivation).
Atropine is a competitive antagonist at muscarinic acetylcholine receptors, meaning it blocks the effects of the excess acetylcholine.
By blocking these receptors, atropine reverses the life-threatening muscarinic effects, such as severe bradycardia, bronchoconstriction, and excessive respiratory secretions.

Option B: Morphine is an opioid analgesic that causes respiratory depression, which would dangerously worsen the respiratory compromise often seen in severe organophosphate poisoning.
Option C: Heparin is an anticoagulant medication used to prevent and treat blood clots. It has no role in counteracting the effects of acetylcholinesterase inhibition.
Option D: Aspirin is a nonsteroidal anti-inflammatory drug (NSAID) with antiplatelet effects. It does not address the underlying pathophysiology of organophosphate poisoning.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacology: Antidotes for Poisoning as background academic context rather than a clinical decision trigger.
Recognizing the signs of a cholinergic crisis (DUMBELS mnemonic) is a critical nursing skill for rapid identification of organophosphate poisoning.
The priority nursing action is always airway, breathing, and circulation (ABCs). In OP poisoning, managing copious airway secretions is paramount to prevent aspiration and respiratory failure.
Nurses must use strict personal protective equipment (PPE) during decontamination to prevent becoming victims of secondary exposure.

How to Approach the Question

First, identify the core of the question, which is asking for the specific antidote to 'organophosphorus poisoning'.
This is a factual recall question based on pharmacological knowledge.
Mentally review the mechanism of organophosphorus poisoning (inhibition of acetylcholinesterase) and the resulting cholinergic effects.
Evaluate each option based on its known pharmacological action.
Atropine is a classic anticholinergic agent used to block muscarinic effects, making it a logical choice.
Eliminate the other options by identifying their primary uses (Morphine for pain, Heparin for anticoagulation, Aspirin for pain/inflammation/antiplatelet), which are unrelated to treating this specific poisoning.

Concept Tested & Keywords

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E6 Ghai Essential Pediatrics(pp 26-904 of 913) p. 755-757

E6 Pharmacology Katzung 16e p. 1618-1620

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 2263-2265

Practise the full UPPSC 2023

Attempt every question from this paper in a timed mock, then review the full solution for each one.