Treatment of Hypocalcemia
The treatment of hypocalcemia requires intravenous calcium gluconate for symptomatic cases and oral calcium supplementation with vitamin D for chronic management, with dosing based on severity and symptom presentation. 1, 2
Acute Symptomatic Hypocalcemia Management
IV Calcium Administration
- For symptomatic hypocalcemia: Administer intravenous calcium gluconate 50-100 mg/kg slowly with ECG monitoring 1
- Administration protocol:
- Dilute calcium gluconate in 5% dextrose or normal saline to a concentration of 10-50 mg/mL for bolus administration 2
- Administer via a secure IV line to avoid calcinosis cutis and tissue necrosis 2
- Do not exceed infusion rate of 200 mg/minute in adults or 100 mg/minute in pediatric patients 2
- Monitor ECG during administration 2
Dosing Based on Severity
- Mild hypocalcemia (ionized calcium 1-1.12 mmol/L): 1-2g IV calcium gluconate is effective in normalizing calcium levels in 79% of patients 3
- Moderate to severe hypocalcemia (ionized calcium <1 mmol/L): 4g IV calcium gluconate infused at 1g/hour is effective in achieving calcium >1 mmol/L in 95% of patients 4
Chronic Hypocalcemia Management
Oral Supplementation
- Calcium supplementation: Calcium carbonate 1000-2000 mg elemental calcium daily in divided doses 1
- Vitamin D supplementation: Cholecalciferol (Vitamin D3) 800-1000 IU daily 1
- Target levels: Maintain serum 25-hydroxyvitamin D level >30 ng/mL 1
Monitoring
- Regular assessment: Monitor serum calcium, magnesium, PTH, and creatinine every 3-6 months until stable, then annually 1
- During IV treatment: Measure serum calcium every 4-6 hours during intermittent infusions and every 1-4 hours during continuous infusion 2
Important Considerations
Address Underlying Causes
- Check magnesium levels: Hypomagnesemia must be corrected as it can impair PTH secretion and action 1
- Evaluate vitamin D status: Vitamin D deficiency is a common cause of chronic hypocalcemia 5
Special Populations
- Renal impairment: Start at lowest dose of recommended range and monitor serum calcium levels every 4 hours 2
- High phosphate levels: Obtain renal consultation as increased calcium might increase risk of calcium phosphate precipitation 1
Avoid Complications
- Drug incompatibilities: Do not mix calcium gluconate with ceftriaxone or administer calcium and sodium bicarbonate through the same line 1, 2
- Potential complications:
- Overcorrection leading to hypercalcemia
- Renal calculi formation
- Renal failure
- Calcinosis cutis and tissue necrosis with extravasation 1
Treatment Algorithm
- Assess severity:
- Symptomatic (tetany, seizures, neuromuscular irritability) → IV calcium
- Asymptomatic → Oral supplementation if chronic
- Check magnesium levels and correct if low
- For symptomatic patients:
- Administer IV calcium gluconate with appropriate monitoring
- Transition to oral therapy once stabilized
- For chronic management:
- Provide oral calcium and vitamin D supplementation
- Monitor levels regularly
- Adjust dosing based on serum calcium levels and symptoms
By following this approach, hypocalcemia can be effectively managed while minimizing the risk of complications.