First-lineCalcium gluconate 10%

Calcium Gluconate

Calcium salt

Antidote to magnesium toxicity; hyperkalaemia cardio-protection.

IV

First-line for

  • Magnesium sulfate toxicity (respiratory depression)
  • Hyperkalaemia cardio-protection
  • Severe hypocalcaemia

Mechanism

Antagonises Mg²⁺ at NMJ; stabilises cardiac membrane.

MgSO4 toxicity

  • Loss of reflexes → call team
  • Resp depression → 1 g calcium gluconate IV

Dosing

Mg toxicity
1 g (10 mL of 10%) slow IV over 10 min
Hyperkalaemia
10 mL of 10% IV over 10 min

Contraindications

  • AbsoluteHypercalcaemia, digoxin toxicity (worsens)

Side effects

  • Hypotension if rapid
  • Extravasation → tissue necrosis

Fetal & maternal notes

  • Safe.

Key interactions

  • Digoxin

    Avoid

    Arrhythmia

  • Ceftriaxone (neonate)

    Avoid

    Precipitation

Clinical pearls

  • 💡 Keep at bedside during MgSO4 infusion.
  • 💡 Calcium chloride only via central line.

Content last reviewed: REPLACE_ME (e.g. 2026-07)

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For educational use only

Not medical advice. Verify dosing against the BNF and your local trust guidelines before prescribing.