Paper I
2015 February (2010 Scheme) · 40 marks · 120 min

Question

Atropine

Q33 marksShort Notes

Answer

Atropine is a non-selective muscarinic receptor antagonist (belladonna alkaloid).

Mechanism of action

  • Competitively blocks muscarinic acetylcholine receptors, preventing the effects of parasympathetic (cholinergic) stimulation

Uses

  • Preanaesthetic medication (reduces secretions, prevents vagal bradycardia)
  • Antidote for organophosphorus/anticholinesterase poisoning
  • Treatment of sinus bradycardia/AV block
  • Mydriatic/cycloplegic (ophthalmic examination)
  • Antispasmodic (GI/biliary/renal colic — reduces smooth muscle spasm)

Adverse effects

  • Dry mouth, blurred vision (cycloplegia), photophobia
  • Tachycardia
  • Urinary retention, constipation
  • Hyperthermia (decreased sweating — “hot as a hare”)
  • CNS effects (excitement, delirium) at high doses
  • Contraindicated in glaucoma (narrow-angle) and prostatic hypertrophy

Other Years Asked


Revise MBBS
Preview