What is the typical dose of calcium gluconate (Ca gluconate) for treating hypocalcemia?

Calcium Gluconate Dosing for Hypocalcemia

Recommended Dosing by Patient Population

For pediatric patients with acute symptomatic hypocalcemia, administer 60 mg/kg of calcium gluconate intravenously, infused over 30-60 minutes. 1

Pediatric Dosing (Including Neonates)

• Standard dose: 60 mg/kg IV infused over 30-60 minutes for mild to moderate hypocalcemia 1
• Emergency/cardiac arrest: Administer by slow IV push with close heart rate monitoring, repeating as necessary for desired clinical effect 1
• Neonates and infants: The same 60 mg/kg dose applies, though asymptomatic cases may be managed with 40-80 mg/kg/day of elemental calcium for maintenance 2
• Acute symptomatic treatment in neonates: 10-20 mg/kg of elemental calcium (1-2 mL/kg of 10% calcium gluconate) given as slow IV infusion for tetany or hypocalcemic seizures 2

Adult Dosing

• Mild hypocalcemia (ionized calcium 1.0-1.12 mmol/L): 1-2 g IV calcium gluconate infused at 1 g/hour 3, 4
• Moderate to severe hypocalcemia (ionized calcium <1.0 mmol/L): 4 g IV calcium gluconate infused at 1 g/hour 4, 5
• The 4 g regimen successfully normalized calcium in 95% of critically ill trauma patients with moderate to severe hypocalcemia 5

Special Clinical Situations

• Calcium channel blocker toxicity: Initial bolus of 0.6 mL/kg of 10% calcium gluconate (30-60 mL or 3-6 grams in adults) IV over 5-10 minutes, followed by continuous infusion at 0.6-1.2 mL/kg/hour 1, 6
• Hyperkalemia (cardiac stabilization): 15-30 mL of 10% calcium gluconate IV over 2-5 minutes 6
• Hypermagnesemia with cardiac arrest: 15-30 mL of 10% calcium gluconate IV over 2-5 minutes 6

Administration Guidelines

Route and Rate

• Administer intravenously only via a secure IV line, preferably through a central venous catheter to minimize extravasation risk 1, 6, 7
• Infusion rate: For non-emergent situations, infuse at 1 g/hour or over 30-60 minutes 1, 3, 4
• Avoid rapid infusion to prevent cardiac arrhythmias and symptomatic bradycardia 1

Dilution

• Dilute with 5% dextrose or normal saline before administration 7
• Do not mix with fluids containing phosphate or bicarbonate, as precipitation will occur 7

Critical Monitoring Requirements

Cardiac Monitoring

• Continuous ECG monitoring is essential during administration, particularly in patients receiving cardiac glycosides 1, 6
• Stop infusion immediately if symptomatic bradycardia occurs or heart rate decreases by 10 beats per minute 1

Laboratory Monitoring

• Intermittent infusions: Measure serum calcium every 4-6 hours 7
• Continuous infusions: Measure serum calcium every 1-4 hours 7
• Post-infusion assessment: Check ionized calcium approximately 10 hours after completion of infusion to ensure equilibration and assess efficacy 4

Important Safety Considerations

Extravasation Risk

• Calcium gluconate is strongly preferred over calcium chloride for peripheral IV administration due to significantly less tissue irritation 1, 6
• Central venous access is preferred; extravasation through peripheral lines may cause severe skin and soft tissue injury, calcinosis cutis, tissue necrosis, ulceration, and secondary infection 1, 6, 7
• If extravasation occurs or calcinosis cutis develops, immediately discontinue administration at that site 7

Drug Interactions

• Cardiac glycosides: Synergistic arrhythmias may occur; if concomitant therapy is necessary, give calcium slowly in small amounts with close ECG monitoring 7
• Calcium channel blockers: Calcium administration may reduce the therapeutic response to these medications 7
• Ceftriaxone: Absolutely contraindicated in neonates ≤28 days old due to risk of fatal intravascular precipitates 7

Special Populations

• Renal impairment: Initiate at the lower end of the dosage range and monitor serum calcium every 4 hours 7
• Elderly patients: Start at the low end of the dosage range 7

Clinical Pearls

• About half of the administered calcium dose is retained in the exchangeable calcium space, with higher doses (4 g vs 2 g) resulting in proportionally more elemental calcium retention 4
• Most hypocalcemic critically ill patients normalize calcium within 4 days of admission, regardless of supplementation 8
• Failure to normalize calcium by day 4 in severely hypocalcemic patients may be associated with doubled mortality (38% vs 19%) 8
• Adjusted calcium <2.2 mmol/L has only 78% sensitivity and 63% specificity for predicting ionized calcium <1.1 mmol/L; ionized calcium measurement is preferred in critical care settings 8
• Low magnesium, sodium, and albumin are independently associated with hypocalcemia; correct hypomagnesemia concurrently for optimal response 8