How the dose is calculated
Calcium gluconate is dosed per single IV administration by weight, using the 10% solution (100 mg/mL).
Typical dosing by indication
| Indication | Dose | Max single dose |
|---|---|---|
| Hyperkalaemia (cardioprotection) | 100 mg/kg IV slow push | 3 g |
| Symptomatic hypocalcaemia | 100 mg/kg IV slow infusion | 2 g |
In hyperkalaemia, calcium gluconate stabilises the cardiac membrane within minutes but does not lower serum potassium — it must be combined with therapies that actually shift or remove potassium (insulin/glucose, salbutamol, dialysis).
Clinical use
- First-line treatment for hyperkalaemia with ECG changes (peaked T waves, widened QRS, loss of P waves) — protects the heart while other measures lower the potassium level.
- Give via a secure IV line — extravasation causes significant local tissue necrosis; central access is preferred when available for repeated or infusion dosing.
- Never mix or co-administer with sodium bicarbonate in the same line — they precipitate together.
Frequently asked questions
Does calcium gluconate lower potassium?
No — it stabilises the cardiac membrane against the effects of hyperkalaemia but does not change the serum potassium level. Other treatments (insulin/glucose, salbutamol, dialysis) are needed to actually lower potassium.
How quickly does calcium gluconate work for hyperkalaemia?
Its cardioprotective effect typically begins within 1-3 minutes and lasts 30-60 minutes, which is why repeat dosing is often needed while other potassium-lowering treatments take effect.
Why shouldn't calcium gluconate be given with sodium bicarbonate?
The two form an insoluble precipitate when mixed, which can occlude the IV line — give them through separate lines or flush thoroughly between the two if only one line is available.
References
- Long B, et al. Emergency medicine management of severe hyperkalaemia. Am J Emerg Med. 2018;36:1057-1065.
- American Heart Association. Pediatric Advanced Life Support (PALS) Guidelines.