What is the antidote for magnesium toxicity?

What is the antidote for magnesium toxicity?

• A. Neostigmine
• B. Calcium
• C. Vitamin K
• D. Furosemide

Answer: (B)

Magnesium toxicity depresses neuromuscular transmission and cardiac conduction because magnesium acts like a calcium blocker. Giving calcium counteracts this effect by increasing the competing intracellular calcium and restoring excitability at the neuromuscular junction and stabilizing cardiac membranes. The standard antidote is calcium given intravenously, typically calcium gluconate, which reverses the depressant effects of the excess magnesium. Neostigmine would raise acetylcholine levels and could worsen weakness. Vitamin K has no role in treating magnesium toxicity. Furosemide may promote magnesium excretion in some situations but does not rapidly reverse the acute toxic effects.

Magnesium toxicity depresses neuromuscular transmission and cardiac conduction because magnesium acts like a calcium blocker. Giving calcium counteracts this effect by increasing the competing intracellular calcium and restoring excitability at the neuromuscular junction and stabilizing cardiac membranes. The standard antidote is calcium given intravenously, typically calcium gluconate, which reverses the depressant effects of the excess magnesium.

Neostigmine would raise acetylcholine levels and could worsen weakness. Vitamin K has no role in treating magnesium toxicity. Furosemide may promote magnesium excretion in some situations but does not rapidly reverse the acute toxic effects.