What is the maximum dose of intravenous (IV) calcium gluconate?

Maximum Dose of Intravenous Calcium Gluconate

For calcium channel blocker toxicity with hemodynamic instability, the maximum dose is 30-60 mL (3-6 grams) of 10% calcium gluconate IV every 10-20 minutes, or as a continuous infusion at 0.6-1.2 mL/kg/hour (0.06-0.12 g/kg/hour). 1

Dosing by Clinical Indication

Acute Symptomatic Hypocalcemia (Adults)

• Mild hypocalcemia: 1-2 grams IV calcium gluconate infused over 30-60 minutes 2
• Moderate to severe hypocalcemia: 2-4 grams IV calcium gluconate, though this dose is often insufficient for severe cases 2, 3
• Higher doses (4 grams) result in significantly more elemental calcium retention compared to 2 grams (201 ± 50 mg versus 81 ± 38 mg), with approximately half of the administered dose retained in the exchangeable calcium space 3

Pediatric Dosing

• Standard dose: 60 mg/kg of calcium gluconate IV, infused over 30-60 minutes 1
• For cardiac arrest or emergency situations, administer by slow push and repeat as necessary for desired clinical effect 1

Calcium Channel Blocker Overdose

• Initial bolus: 0.6 mL/kg of 10% calcium gluconate solution (0.3 mEq/kg) IV over 5-10 minutes 1
• Maintenance infusion: 0.3 mEq/kg per hour 1
• Maximum for hemodynamic instability: 30-60 mL (3-6 grams) every 10-20 minutes, or continuous infusion at 0.6-1.2 mL/kg/hour 1

Hyperkalemia (Cardiac Stabilization)

• Adult dose: 15-30 mL of 10% calcium gluconate over 2-5 minutes 4
• Pediatric dose: 60 mg/kg IV 1

Critical Administration Guidelines

Infusion Rate Considerations

• Standard infusion rate should not exceed 1 gram per hour to minimize adverse effects 2, 3
• For therapeutic plasma exchange, 1.6 g/hour is superior to 1.0 g/hour for maintaining ionized calcium levels and preventing hypocalcemic reactions 5
• Rapid infusion must be avoided to prevent cardiac arrhythmias and symptomatic bradycardia 1

Monitoring Requirements

• Stop infusion immediately if symptomatic bradycardia occurs or heart rate decreases by 10 beats per minute 1
• Continuous ECG monitoring is essential during administration 1
• Monitor serum ionized calcium levels to prevent hypercalcemia, especially during continuous infusions 4
• Reassess ionized calcium at least 10 hours after completion of infusion to ensure equilibration and assess therapy efficacy 3

Safety Considerations

Route of Administration

• Central venous catheter is strongly preferred over peripheral IV 1, 4
• Extravasation through peripheral IV may cause severe skin and soft tissue injury 1, 4
• Calcium gluconate is preferred over calcium chloride for peripheral administration due to less tissue irritation 1

Important Precautions

• Do not mix calcium with vasoactive amines 1
• Calcium chloride provides more rapid increase in ionized calcium than calcium gluconate and is preferred for critically ill patients, though it requires central access 4
• Individual response to calcium therapy is highly variable, even when normalized to body weight 2

Common Pitfalls

The evidence reveals that moderate to severe hypocalcemia often requires doses exceeding the standard 2-4 gram range, with only 38% of patients responding adequately to 2-4 grams 2. For calcium channel blocker toxicity specifically, much higher doses (up to 6 grams per bolus) may be necessary and are supported by expert consensus 1. The key is to titrate based on clinical response and ionized calcium levels rather than adhering rigidly to a single maximum dose, while maintaining appropriate infusion rates and monitoring protocols.