Question
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- (a) Outline the management of Organophospherous poisoning. ( 4 mark(s)
- (b) Write the mechanism of action, therapeutic uses and adverse effects of Pancuronium. 4 mark(s)
Answer
a) Management of organophosphorus poisoning
- General measures: remove from contaminated area, decontaminate skin, maintain airway/breathing/circulation, suction secretions, oxygen.
- Atropine — competitively blocks muscarinic receptors, reversing bronchorrhoea, bronchospasm, bradycardia, secretions; titrated to effect, often requiring large repeated doses.
- Pralidoxime (2-PAM) — reactivates acetylcholinesterase, reversing both muscarinic and nicotinic effects, most effective given early before the enzyme-organophosphate complex “ages.”
- Diazepam — controls seizures/agitation, reduces mortality when given alongside atropine and pralidoxime.
b) Pancuronium — mechanism, uses, adverse effects A long-acting, non-depolarizing (competitive) neuromuscular blocker.
Mechanism: occupies nicotinic receptors at the neuromuscular junction without activating them, competitively blocking acetylcholine from triggering the endplate potential — surmountable, reversible with anticholinesterases (neostigmine).
Uses: skeletal muscle relaxation for prolonged surgery requiring sustained relaxation (60-120 min duration).
Adverse effects: prolonged neuromuscular blockade/apnea if not adequately reversed, tachycardia (vagolytic/ganglion-blocking action, distinguishing it from other non-depolarizing blockers), minimal histamine release compared to older agents like d-tubocurarine.