What is the recommended dose for managing hypocalcemia (low calcium levels)?

Management of Hypocalcemia with Exact Dosing

For symptomatic hypocalcemia or ionized calcium <3.6 mg/dL, administer IV calcium gluconate 1-2 g (10-20 mL of 10% solution) or calcium chloride 0.5-1 g (5-10 mL of 10% solution) by slow IV push over 10-20 minutes. 1, 2, 3

IV Calcium Administration

Calcium Gluconate (Preferred for peripheral administration)

• Dose: 1-2 g IV (100 mg/mL, 10% solution)
• Elemental calcium content: 9.3 mg (0.47 mEq) per 100 mg
• Administration rate: Slow IV push or infusion, not exceeding 1 mL/min
• Monitoring: ECG monitoring recommended, especially with cardiac glycosides

Calcium Chloride (For central line administration)

• Dose: 0.5-1 g IV (100 mg/mL, 10% solution)
• Elemental calcium content: 27 mg (1.4 mEq) per 100 mg (3x more than gluconate)
• Administration rate: Very slow IV push, not exceeding 1 mL/min
• Route: Preferably via central or deep vein to avoid tissue necrosis

Pediatric Dosing

• Calcium chloride: 20 mg/kg (0.2 mL/kg of 10% solution) 4
• Calcium gluconate: 50-100 mg/kg for symptomatic patients 4

Severity-Based Management Algorithm

Severe, Symptomatic Hypocalcemia (Tetany, seizures, QT prolongation)

1. Immediate IV calcium:
   • Adults: Calcium gluconate 1-2 g IV over 10-20 minutes
   • Children: Calcium gluconate 50-100 mg/kg IV slowly with ECG monitoring 4
2. Follow-up dosing: May repeat every 6 hours as needed based on calcium levels
3. Continuous infusion: For persistent hypocalcemia, consider 4 g calcium gluconate infused at 1 g/hour 5

Moderate Hypocalcemia (Ionized calcium 0.9-1.0 mmol/L, asymptomatic)

1. IV calcium: 1-2 g calcium gluconate IV over 20-30 minutes 6
2. Monitor: Recheck ionized calcium in 4-6 hours
3. Transition to oral: Begin oral supplementation when stable

Mild Hypocalcemia (Ionized calcium 1.0-1.12 mmol/L)

1. Oral calcium: 1,000-1,500 mg elemental calcium daily in divided doses 1
2. Monitor: Recheck calcium in 2-4 weeks

Important Precautions

1. Extravasation risk: Calcium chloride can cause severe tissue necrosis if extravasated; use central line when possible 7

2. Infusion compatibility: Calcium is incompatible with phosphate or bicarbonate-containing solutions; precipitation may occur 3

3. Cardiac monitoring: ECG monitoring recommended during administration, especially with:

   • Concurrent cardiac glycosides (risk of arrhythmias)
   • Rapid administration (risk of hypotension, bradycardia)

4. Contraindications:

   • Hypercalcemia
   • Neonates receiving ceftriaxone (risk of fatal precipitates) 3

5. Monitoring frequency:

   • During intermittent infusions: Every 4-6 hours
   • During continuous infusion: Every 1-4 hours 3

Special Considerations

• For critically ill trauma patients with moderate-severe hypocalcemia, a 4 g calcium gluconate infusion at 1 g/hour has shown 95% success in achieving ionized calcium >1.0 mmol/L 5

• In patients with chronic kidney disease, maintain corrected calcium in the normal range (8.4-9.5 mg/dL) and monitor calcium-phosphorus product 1

• For post-parathyroidectomy hypocalcemia, IV calcium administration is recommended with careful monitoring 1