Management of Hypocalcaemia

Drug therapy / treatment options

Mild Hypocalcaemia: serum adjusted calcium 1.9 - 2.2mmol/L and asymptomatic

Commence oral calcium supplement e.g. Calcichew Forte Chewable, 2 tablets twice a day* (unlicensed dose) and adjust to patient's individual requirements.

• If post-thyroidectomy, repeat serum calcium 24 hours later. Then if:
  • Serum adjusted calcium >2.2mmol/L, patient may be discharged with plan to re-check serum calcium within one week.
  • Serum adjusted calcium remains between 1.9-2.2mmol/L, increase Calcichew Forte Chewable to three tablets twice a day (unlicensed dose)*.
  • Patient remains in mild hypocalcaemic range 72 hours post-operatively despite calcium supplementation, start alfacalcidol oral 0.25microgram daily. Alfacalcidol is restricted to specialist initiation; contact a senior member of medical staff to discuss use.
• If vitamin D deficient, commence oral vitamin D supplementation: load with colecalciferol as per the GGC Vitamin D deficiency guideline (refer to flowchart 2 under osteomalacia).
• If patient has hypomagnesaemia, stop any precipitating drug and administer IV magnesium (see the Management of Hypomagnesaemia guideline).

*This is an unlicensed dose of Calcichew Forte Chewable tablets. Review on discharge, and if appropriate, prescribe the licensed dose (1 tablet daily).

Severe Hypocalcaemia: serum adjusted calcium <1.9mmol/L and/or symptomatic

This is a medical emergency. Administer calcium gluconate 10% IV as follows:

• Initially, give calcium gluconate 10% IV 10-20ml in glucose 5% IV 50-100ml over 10 minutes, with ECG monitoring. This can be repeated until the patient is asymptomatic.
• Followed by a continuous IV infusion:
  • Dilute calcium gluconate 10% IV 100ml (10 x 10ml ampoules) in one litre of sodium chloride 0.9% or glucose 5% and infuse at 50-100ml/hour. Titrate the rate to achieve normocalcaemia and continue until treatment of the underlying cause has taken effect.