Calcium Gluconate 1 Gram: Dosage and Administration
For acute symptomatic hypocalcemia requiring IV calcium gluconate, administer 1-2 grams (1000-2000 mg) as a slow IV bolus diluted to 10-50 mg/mL, infused at no more than 200 mg/minute in adults or 100 mg/minute in pediatric patients, with continuous ECG monitoring. 1
Essential Composition Information
- One gram (1000 mg) of calcium gluconate contains only 93 mg of elemental calcium 2, 1
- A standard 10-mL ampule of 10% calcium gluconate provides 1000 mg calcium gluconate = 93 mg elemental calcium 3, 2
- This 9.3% elemental calcium content is critical for dosing calculations 1
Administration Protocol for IV Calcium Gluconate
Bolus Administration
- Dilute calcium gluconate in 5% dextrose or normal saline to a concentration of 10-50 mg/mL before administration 1
- Maximum infusion rate: 200 mg/minute in adults, 100 mg/minute in pediatric patients including neonates 1
- For a 1-gram dose, this translates to a minimum infusion time of 5 minutes in adults and 10 minutes in children 1
- Administer via a secure IV line to prevent calcinosis cutis and tissue necrosis from extravasation 1
- Use a central line when possible to minimize extravasation risk 4
Continuous Infusion (Post-Parathyroidectomy or Severe Hypocalcemia)
- Dilute to 5.8-10 mg/mL concentration for continuous infusion 1
- Infusion rate: 1-2 mg elemental calcium per kg body weight per hour 3
- For a 70-kg adult, this equals approximately 70-140 mg elemental calcium/hour, requiring 750-1500 mg calcium gluconate/hour 3
- Target ionized calcium: 1.15-1.36 mmol/L (4.6-5.4 mg/dL) 3
Monitoring Requirements
During Acute Administration
- Continuous ECG monitoring during bolus administration, especially in hyperkalemia 1
- Monitor vital signs throughout infusion 1
Post-Parathyroidectomy Protocol
- Measure ionized calcium every 4-6 hours for the first 48-72 hours after surgery, then twice daily until stable 3, 4
- During intermittent infusions: measure serum calcium every 4-6 hours 1
- During continuous infusion: measure serum calcium every 1-4 hours 1
Renal Impairment
- Start at the lowest recommended dose and monitor calcium levels every 4 hours 1
- Exercise particular caution as these patients are at higher risk for hypercalcemia 3
Critical Drug Incompatibilities
- Never mix calcium gluconate with ceftriaxone - can form fatal precipitates 1
- Contraindicated with ceftriaxone in neonates ≤28 days old 1
- In patients >28 days, flush lines thoroughly between ceftriaxone and calcium administration 1
- Do not mix with bicarbonate or phosphate-containing fluids - precipitation will occur 1
- Do not mix with minocycline - calcium complexes and inactivates it 1
Transition to Oral Therapy
- When oral intake is possible, transition to calcium carbonate 1-2 grams three times daily 3, 4
- Add calcitriol up to 2 mcg/day to maintain ionized calcium in normal range 3
- Gradually reduce IV infusion as ionized calcium stabilizes in normal range 3
Special Clinical Scenarios
Emergency Situations (Hyperkalemia/Hypermagnesemia)
- Administer 15-30 mL of 10% calcium gluconate (1500-3000 mg) IV over 2-5 minutes 2
- Stop immediately if symptomatic bradycardia occurs 2
Hyperphosphatemia Caution
- Exercise extreme caution in patients with elevated phosphate levels due to risk of calcium-phosphate precipitation causing tissue calcification and obstructive uropathy 4
- May need to discontinue or reduce phosphate binders after parathyroidectomy 3
Common Pitfalls to Avoid
- Do not confuse calcium gluconate with calcium chloride - calcium chloride contains significantly more elemental calcium and should be avoided in CKD patients due to metabolic acidosis risk 2, 5
- Do not exceed 500 mg elemental calcium absorption at one time for oral supplementation 6
- Inspect solution before use - should be clear and colorless to slightly yellow; discard if particulate matter present 1
- Use diluted solution immediately after preparation 1