A patient with myasthenia gravis crisis is inadvertently given excess neostigmine. Which of the following signs would most reliably distinguish cholinergic crisis from myasthenic crisis?

• A Fasciculations and miosis ✓
• B Worsening ptosis and diplopia
• C Improvement after edrophonium injection
• D Hypertension and tachycardia

Explanation

Cholinergic crisis results from excess acetylcholine causing nicotinic (fasciculations, muscle weakness) and muscarinic (miosis, bradycardia, salivation) features. Edrophonium worsens cholinergic crisis but transiently improves myasthenic crisis, making fasciculations and miosis the hallmarks of cholinergic toxicity. Hypertension and tachycardia are not seen with cholinergic excess.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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