Calcium Gluconate Dosing and Administration for Hypocalcemia
For acute symptomatic hypocalcemia, administer calcium gluconate 50-100 mg/kg intravenously as a slow infusion over 30-60 minutes with continuous ECG monitoring, preferably through a central venous catheter. 1, 2
Dosing by Severity and Patient Population
Acute Symptomatic Hypocalcemia (Tetany, Seizures)
- Administer 50-100 mg/kg IV as a single dose, infused over 30-60 minutes 1, 2
- For adults, this translates to approximately 1-2 grams for mild hypocalcemia (ionized calcium 1.0-1.12 mmol/L) 3
- For moderate to severe hypocalcemia (ionized calcium <1.0 mmol/L), use 4 grams IV infused at 1 g/hour 4
- This 4-gram regimen successfully normalizes calcium in 95% of critically ill patients with moderate to severe hypocalcemia 4
Pediatric Dosing
- 60 mg/kg IV for hypocalcemia, hyperkalemia, hypermagnesemia, or calcium channel blocker toxicity 5, 2
- Administer slowly with heart rate monitoring; repeat as necessary for desired clinical effect 5
Alternative Dosing Protocol
- 0.3 mEq/kg (0.6 mL/kg of 10% calcium gluconate solution) IV over 5-10 minutes, followed by continuous infusion of 0.3 mEq/kg per hour 2
- Titrate infusion rate to achieve adequate hemodynamic response 2
Administration Route and Technique
Preferred Access
- Use a central venous catheter whenever possible to prevent severe skin and soft tissue injury from extravasation 5, 6, 2
- Peripheral IV extravasation can cause tissue necrosis, ulceration, and secondary infection 7
Infusion Rate
- Infuse over 30-60 minutes for most indications 1, 2
- For cardiac arrest situations only, may give by slow push 2
- Rapid administration can cause hypotension, bradycardia, and cardiac arrhythmias 7
Dilution
- Dilute with 5% dextrose or normal saline before administration 7
- Each mL contains 100 mg calcium gluconate, which provides 9.3 mg (0.4665 mEq) of elemental calcium 7
Critical Monitoring Requirements
During Administration
- Continuous ECG monitoring is mandatory, especially in patients with hyperkalemia 6, 1
- Stop injection immediately if symptomatic bradycardia occurs 5
Laboratory Monitoring
- Measure serum calcium every 4-6 hours during intermittent infusions 7
- During continuous infusion, check calcium every 1-4 hours 7
- Monitor ionized calcium levels to avoid severe hypercalcemia (>2× upper limit of normal) 2
Post-Parathyroidectomy Patients
- Measure ionized calcium every 4-6 hours for the first 48-72 hours after surgery, then twice daily until stable 1
Important Precautions and Contraindications
Cardiac Glycoside Use
- If concomitant digoxin therapy is necessary, give calcium gluconate slowly in small amounts with close ECG monitoring 7
- Synergistic arrhythmias may occur with combined use 7
Hyperphosphatemia
- Exercise extreme caution in patients with hyperphosphatemia due to risk of calcium phosphate precipitation in tissues and obstructive uropathy 6, 1
- This is particularly critical in tumor lysis syndrome 6
Cardiac Arrest Situations
- Calcium chloride is preferred over calcium gluconate in cardiac arrest due to more rapid increase in ionized calcium concentration 6, 2
- Calcium gluconate may be substituted if calcium chloride is unavailable 5
Drug Incompatibilities
- Do not mix with fluids containing phosphate or bicarbonate—precipitation will result 7
- Do not mix with vasoactive amines 5
Extravasation Management
- If extravasation occurs or calcinosis cutis develops, immediately discontinue infusion at that site 7
- Calcinosis cutis can occur with or without extravasation 7
Chronic Hypocalcemia Management
Oral Supplementation
- For asymptomatic or chronic hypocalcemia, oral calcium supplementation may be sufficient 1
- Post-parathyroidectomy: calcium carbonate 1-2 grams three times daily with calcitriol to maintain ionized calcium in normal range 1
- Calcium carbonate contains 40% elemental calcium; calcium gluconate contains only 9% elemental calcium 5
Response Variability
- Individual response to calcium therapy is highly variable, even when normalized to body weight 3
- The 1-2 gram regimen is effective for 79% of patients with mild hypocalcemia but only 38% with moderate to severe hypocalcemia 3
Common Pitfalls to Avoid
- Never use calcium carbonate as a phosphate binder in patients with hyperphosphatemia and elevated calcium levels 6
- Do not administer through peripheral IV if central access is available—extravasation risk is too high 5, 6, 2
- Do not infuse rapidly—this causes cardiovascular complications 7
- Do not use in neonates (≤28 days) receiving ceftriaxone—fatal precipitates can form 7