Calcium – useful antidote for calcium channel blockers, hydrofluoric acid exposure to skin or systemic fluorosis, ethylene glycol (hypocalcaemia), hyperkalaemia and iatrogenic hypermagnesaemia.


  • 0.5-1g (5-10ml) of calcium chloride or 1-2g (10-20ml) of calcium gluconate IV over 5-10 minutes.
  • Repeat every 10-15 minutes as required. Usually this is guided by serum calcium concentrations or the QT interval on the ECG.
  • Calcium chloride can be given as a bolus into a large vein and does not require metabolism by the liver to work, however, if it extravasates local tissue damage can occur.

Calcium channel blocker poisoning

  • Give 2g (20ml) of calcium chloride IV or 6g (60ml) of calcium gluconate IV over 5-10 minutes.
  • This dose may be repeated every 20 mins for up to three doses

Hydrofluoric (HF) acid skin exposure

  • Topical 2.5% calcium gel – place on minor burns or if on the hand place gel into a glove followed by the injured hand (mix 10mL of 10%calcium gluconate solution with 30 mL lubricant jelly).
  • Local injection of calcium gluconate 1g/10ml intradermal or subcutaneously (not into fingers) if topical solution does not work. Do not use calcium chloride as this will cause tissue injury
  • Bier’s block is the third line or used if there is a large HF burn. Use as per normal Bier’s technique for 20 minutes. Inject 1g (10ml) of calcium gluconate in 40ml of 0.9% saline. Do not use calcium chloride as this will cause tissue injury
  • Intra-arterial infusion. As a final alternative, if pain is still an issue it is possible to infuse a solution into an artery of the affected limb. Dilute 1g (10ml) of calcium gluconate in 40ml go 0.9% saline over 4 hours and repeat as required. Do not use calcium chloride as this will cause tissue injury

Hydrofluoric acid inhalation injury

  • Give nebulised 2.5% calcium gluconate solution.

Paediatric dosing

  • For hypocalcaemia or calcium channel blocker poisoning use 0.5ml/kg of 10% calcium gluconate (max dose 20ml) over 5-10 minutes and repeat after 10-15 minutes if necessary.


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Toxicology Library


Dr Neil Long BMBS FACEM FRCEM FRCPC. Emergency Physician at Kelowna hospital, British Columbia. Loves the misery of alpine climbing and working in austere environments (namely tertiary trauma centres). Supporter of FOAMed, lifelong education and trying to find that elusive peak performance.

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