How to Administer Calcium Gluconate for Hypocalcemia
For acute symptomatic hypocalcemia, administer calcium gluconate 50-100 mg/kg IV (up to 1-2 grams in adults) infused slowly over 30-60 minutes with continuous ECG monitoring. 1
Dosing Based on Severity
Mild Hypocalcemia (ionized Ca 1.0-1.12 mmol/L)
- Adults: 1-2 grams calcium gluconate IV infused at 1 gram/hour 2
- Pediatrics: 60 mg/kg calcium gluconate infused over 30-60 minutes 1, 2
Moderate to Severe Hypocalcemia (ionized Ca <1.0 mmol/L)
- Adults: 4 grams calcium gluconate IV infused at 1 gram/hour over 4 hours 2
- Pediatrics: 50-100 mg/kg calcium gluconate IV infused slowly over 30-60 minutes 1, 2
Life-Threatening Arrhythmias
- 100-200 mg/kg/dose calcium gluconate via slow infusion with ECG monitoring for bradycardia 1
- For cardiac arrest or life-threatening hyperkalemia/hypermagnesemia: 10-30 mL of 10% calcium gluconate over 2-10 minutes with continuous ECG monitoring 1
Route and Vascular Access
Administer intravenously via a secure IV line - either bolus or continuous infusion 3
- Central venous catheter is strongly preferred to minimize extravasation risk 1
- If only peripheral access available, calcium gluconate is preferred over calcium chloride (which is more caustic), but the line must be secure and closely monitored 1
- Calcium gluconate is preferred for peripheral administration due to significantly less tissue irritation and lower risk of severe skin necrosis from extravasation 2
Important caveat: In trauma, massive transfusion, and critically ill patients with liver dysfunction, calcium chloride is actually preferred because it delivers 3 times more elemental calcium and produces more rapid increases without requiring hepatic metabolism 2
Preparation and Concentration
- 10% calcium gluconate solution contains 100 mg calcium gluconate per mL 3
- This provides 9.3 mg (0.4665 mEq) of elemental calcium per mL 3
- A 10-mL ampule of 10% calcium gluconate contains 90 mg of elemental calcium 1
Critical Monitoring Requirements
Cardiac Monitoring
- Continuous ECG monitoring is essential during administration 1
- Stop infusion immediately if symptomatic bradycardia occurs or heart rate decreases by 10 beats per minute 1
- Even "slow push" administration (over 5-10 minutes for emergencies) carries arrhythmia risk and requires careful rate control 1
Laboratory Monitoring
- During intermittent infusions: Measure serum calcium every 4-6 hours 3
- During continuous infusion: Measure serum calcium every 1-4 hours 3
- Post-parathyroidectomy patients: Measure ionized calcium every 4-6 hours for first 48-72 hours, then twice daily until stable 1
Absolute Contraindications and Critical Pitfalls
Never Mix With:
- Never mix with sodium bicarbonate - causes immediate precipitation 1, 2
- Never mix with phosphate-containing fluids - causes precipitation 1, 2, 3
- Do not mix with vasoactive amines 1, 2
Drug Interactions
- Digoxin/cardiac glycosides: Synergistic arrhythmias may occur; if absolutely necessary, give slowly in small amounts with close ECG monitoring 1
- Calcium channel blockers: Calcium may reduce response, but in CCB overdose causing bradycardia, calcium is actually indicated 1
Special Precautions
- Correct magnesium deficiency first - hypocalcemia cannot be fully corrected without adequate magnesium 2
- Exercise caution when phosphate levels are elevated - increased calcium may precipitate calcium phosphate in tissues causing obstructive uropathy; consider renal consultation before aggressive replacement 1
Special Clinical Situations
Calcium Channel Blocker Toxicity with Hemodynamic Instability
- 30-60 mL (3-6 grams) of 10% calcium gluconate IV every 10-20 minutes, or as continuous infusion at 0.6-1.2 mL/kg/hour (0.06-0.12 g/kg/hour) 1
Post-Parathyroidectomy
- For ionized calcium below 0.9 mmol/L: Initiate calcium gluconate infusion at 1-2 mg elemental calcium per kg per hour 1
- Adjust infusion rate to maintain ionized calcium in normal range (1.15-1.36 mmol/L) 1
Tumor Lysis Syndrome
- Asymptomatic hypocalcemia does not require treatment 1, 2
- For symptomatic patients: 50-100 mg/kg IV calcium gluconate administered slowly with ECG monitoring 2
Administration Rate and Safety
- Avoid rapid infusion to prevent cardiac arrhythmias, hypotension, and symptomatic bradycardia 1, 2
- Standard rate: 1 gram/hour for non-emergent situations 2, 4, 5
- Dilute with 5% dextrose or normal saline before infusion 1
Extravasation Management
If extravasation occurs or clinical manifestations of calcinosis cutis are noted, immediately discontinue IV administration at that site 3