Magnesium NMJ Effect — FRCA Primary MCQ

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HardPharmacology - CardiovascularMagnesium NMJ EffectFRCA Primary

Magnesium potentiates non-depolarising neuromuscular block by:

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Correct answer: B — Reducing presynaptic acetylcholine release by competing with calcium

Magnesium competes with calcium at the presynaptic nerve terminal reducing ACh release. It also decreases postjunctional sensitivity and muscle fibre excitability. Dose adjustment is required in renal failure. It causes vasodilation and hypotension.

Reference: Peck Hill Williams 2014 Pharmacology for Anaesthesia and Intensive Care