Calcium Gluconate Dosing for Acute Hypocalcemia
For acute symptomatic hypocalcemia in adults and pediatric patients, 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, 2
Dosing by Severity and Age Group
Pediatric Patients
- Symptomatic hypocalcemia: 50-100 mg/kg IV calcium gluconate, administered slowly with ECG monitoring 1
- Standard dose: 60 mg/kg IV infused over 30-60 minutes 2
- Life-threatening arrhythmias (hyperkalemia context): 100-200 mg/kg/dose via slow infusion with ECG monitoring for bradycardia 1
Adult Patients
- Mild hypocalcemia (iCa 1.0-1.12 mmol/L): 1-2 grams IV calcium gluconate 3, 4
- Moderate to severe hypocalcemia (iCa <1.0 mmol/L): 2-4 grams IV calcium gluconate 1, 4, 5
- Infusion rate: 1 gram per hour 4, 5
Neonates
- Acute symptomatic treatment: 10-20 mg/kg of elemental calcium (1-2 mL/kg of 10% calcium gluconate) as slow IV infusion 6
- Maintenance for asymptomatic: 40-80 mg/kg/day of elemental calcium 6
Administration Protocol
Route and Monitoring
- Administer intravenously via a secure IV line, preferably through a central venous catheter to minimize extravasation risk 2, 7
- Continuous ECG monitoring is mandatory during administration 2, 7
- Stop infusion immediately if symptomatic bradycardia occurs or heart rate decreases by 10 beats per minute 2
Infusion Rate
- Dilute with 5% dextrose or normal saline before administration 7
- Infuse over 30-60 minutes for non-emergent situations 2, 4
- Maximum rate: 1 gram per hour for adults 4, 5
Monitoring Requirements
Laboratory Monitoring
- During intermittent infusions: Measure serum calcium every 4-6 hours 7
- During continuous infusion: Measure serum calcium every 1-4 hours 7
- Post-infusion assessment: Check iCa at least 10 hours after completion to ensure equilibration 4
Target Levels
- Goal ionized calcium: >1.12 mmol/L (normal range 1.15-1.36 mmol/L) 4, 5
- Minimum acceptable: >1.0 mmol/L 5
Critical Pitfalls to Avoid
Drug Incompatibilities
- Never mix with phosphate-containing fluids or bicarbonate - precipitation will occur 1, 7
- Do not administer through the same line as sodium bicarbonate 1
- Do not mix with vasoactive amines 2
Extravasation Risk
- Calcium gluconate extravasation causes severe tissue necrosis, ulceration, and calcinosis cutis 7
- Calcium gluconate is preferred over calcium chloride for peripheral administration due to less tissue irritation 2
- If extravasation occurs, immediately discontinue infusion at that site 7
Cardiac Considerations
- In patients receiving cardiac glycosides, administer calcium slowly in small amounts with close ECG monitoring due to synergistic arrhythmia risk 7
- Avoid rapid administration to prevent hypotension, bradycardia, and cardiac arrhythmias 7
Special Clinical Contexts
High Phosphate Levels
- Exercise caution when phosphate levels are elevated - increased calcium may precipitate calcium phosphate in tissues causing obstructive uropathy 1
- Consider renal consultation if phosphate levels are high before aggressive calcium replacement 1
Efficacy Considerations
- Mild hypocalcemia: 1-2 grams IV calcium gluconate normalizes iCa in approximately 79% of patients 3
- Moderate to severe hypocalcemia: 4 grams IV calcium gluconate normalizes iCa in 95% of patients, with 70% achieving >1.12 mmol/L 5
- About half of administered elemental calcium is retained in the exchangeable calcium space 4
Calcium Gluconate vs. Calcium Chloride
- Calcium gluconate 10% contains 9.3 mg elemental calcium per mL (93 mg per 10 mL) 7
- Calcium chloride is approximately 3 times more potent (270 mg elemental calcium per 10 mL) and produces more rapid increases in ionized calcium 8
- However, calcium gluconate remains the standard for peripheral administration due to safety profile 2