How should intravenous calcium gluconate be dosed, diluted, infused, and monitored in adults with symptomatic hypocalcemia, hyperkalemia, or calcium‑channel‑blocker toxicity, and in pediatric patients?

How to Administer Calcium Gluconate

For adults with symptomatic hypocalcemia, administer 1–2 grams (10–20 mL of 10% solution) intravenously over 10 minutes with continuous ECG monitoring, followed by a continuous infusion of 0.5–2 mg/kg/hour of elemental calcium (approximately 5–20 mL/hour of 10% calcium gluconate) titrated to maintain ionized calcium 1.1–1.3 mmol/L. 1, 2

Preparation and Dilution

• Dilute calcium gluconate in 5% dextrose or normal saline before administration to a concentration of 10–50 mg/mL for bolus dosing or 5.8–10 mg/mL for continuous infusion. 2
• Inspect the solution visually—it should appear clear and colorless to slightly yellow; discard if particulate matter or discoloration is present. 2
• Use the diluted solution immediately after preparation. 2
• Each 10 mL of 10% calcium gluconate contains 100 mg calcium gluconate, which provides 9.3 mg (0.465 mEq) of elemental calcium. 2

Dosing by Clinical Indication

Symptomatic Hypocalcemia (Adults)

• Initial bolus: 1–2 grams (10–20 mL of 10% solution) IV over 10 minutes, which can be repeated until symptoms resolve. 1, 3
• Continuous infusion: Dilute 10 grams (100 mL of 10% solution, or 10 vials) in 1 liter of normal saline or 5% dextrose and infuse at 50–100 mL/hour (0.5–1 gram/hour). 3
• Titrate the infusion rate to maintain ionized calcium in the normal range (1.1–1.3 mmol/L). 1, 4

Symptomatic Hypocalcemia (Pediatric)

• Acute treatment: 50–100 mg/kg IV infused slowly over 30–60 minutes with continuous ECG monitoring. 1
• Life-threatening situations (seizures, arrhythmias): 100–200 mg/kg/dose via slow infusion with ECG monitoring. 1, 5
• For neonates and infants, 60 mg/kg infused over 30–60 minutes is recommended. 1

Hyperkalemia with Cardiac Manifestations

• Adults: 10–30 mL of 10% calcium gluconate IV over 2–5 minutes for immediate cardiac membrane stabilization. 1, 5, 6
• Pediatric: 100–200 mg/kg/dose via slow infusion with ECG monitoring for bradycardia. 1, 5
• Effects begin within 1–3 minutes but last only 30–60 minutes; calcium does not lower potassium levels—it only protects against arrhythmias. 5

Calcium Channel Blocker Toxicity

• Adults: 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). 7, 1
• Calcium gluconate is preferred over calcium chloride for peripheral administration to minimize vein irritation. 7, 1
• Titrate to hemodynamic response rather than fixed dosing schedules. 7

Rate of Administration

• Maximum bolus rate: DO NOT exceed 200 mg/minute in adults or 100 mg/minute in pediatric patients, including neonates. 2
• For emergency situations (cardiac arrest, life-threatening hyperkalemia), 10–30 mL of 10% calcium gluconate can be given over 2–10 minutes with continuous ECG monitoring. 1
• For non-emergent symptomatic hypocalcemia, infuse over 30–60 minutes to reduce cardiac complications. 1, 2

Vascular Access and Extravasation Prevention

• Central venous access is strongly preferred to avoid calcinosis cutis, severe skin necrosis, and tissue injury from extravasation. 1, 5, 2
• If only peripheral access is available, ensure the IV line is secure and closely monitored; calcium gluconate is preferred over calcium chloride (which is more caustic). 1
• Administer via a secure intravenous line to prevent extravasation injury. 2

Monitoring Requirements

During Administration

• Continuous ECG monitoring is mandatory during all calcium administrations. 1, 5, 2
• Stop the infusion immediately if symptomatic bradycardia occurs or heart rate decreases by ≥10 beats per minute. 1, 5
• Monitor vital signs continuously, particularly in patients with pre-existing cardiac rhythm abnormalities. 1

Laboratory Monitoring

• Measure ionized calcium every 4–6 hours during intermittent infusions and every 1–4 hours during continuous infusion. 2
• In post-parathyroidectomy patients, measure ionized calcium every 4–6 hours for the first 48–72 hours, then twice daily until stable. 1
• Target ionized calcium >0.9 mmol/L minimum to prevent cardiac dysrhythmias, with optimal range 1.1–1.3 mmol/L. 1, 4

Critical Drug Incompatibilities

• Never mix calcium gluconate with sodium bicarbonate in the same IV line—precipitation will occur. 1, 5, 2
• Do not mix with phosphate-containing fluids—calcium-phosphate precipitation can cause obstructive uropathy. 1, 2
• Do not mix with ceftriaxone—concurrent use can lead to fatal ceftriaxone-calcium precipitates, and concomitant use is contraindicated in neonates ≤28 days old. 2
• Do not mix with vasoactive amines (epinephrine, dopamine, norepinephrine) or minocycline. 1, 2
• Calcium and vasopressors can be administered via separate lines simultaneously; Y-site compatibility has been demonstrated for insulin, epinephrine, and norepinephrine when properly prepared. 8

Special Clinical Situations

Renal Impairment

• Initiate at the lowest dose of the recommended range and monitor ionized calcium every 4 hours. 2
• Exercise extreme caution when phosphate levels are elevated—additional calcium increases the risk of calcium-phosphate precipitation in tissues. 1
• Consider renal consultation before aggressive calcium replacement in hyperphosphatemic patients. 1

Digoxin Therapy

• Avoid calcium administration in patients receiving digoxin whenever possible. 1
• If absolutely necessary, administer slowly in small aliquots with close ECG monitoring to prevent precipitating digoxin toxicity and life-threatening arrhythmias. 1

Tumor Lysis Syndrome

• Treat only symptomatic patients—asymptomatic hypocalcemia does not require treatment. 1
• Use extreme caution; give a single cautious dose and repeat only for persistent tetany or seizures. 1

Massive Transfusion

• Hypocalcemia results from citrate-mediated chelation from blood products (especially FFP and platelets). 4
• Maintain ionized calcium >0.9 mmol/L minimum during massive transfusion, with optimal target 1.1–1.3 mmol/L. 4
• Titrate calcium replacement to measured ionized calcium response rather than to volume of blood products administered. 4

Common Pitfalls to Avoid

• Do not treat asymptomatic hypocalcemia—even in tumor lysis syndrome, no calcium replacement is indicated without symptoms. 1
• Check and correct magnesium deficiency first—hypomagnesemia is present in 28% of hypocalcemic ICU patients and prevents calcium correction. 4
• Avoid rapid infusion—this causes cardiac arrhythmias, symptomatic bradycardia, and hypotension. 1
• Standard coagulation tests may appear normal despite significant hypocalcemia-induced coagulopathy because laboratory samples are recalcified before analysis. 4
• Correcting acidosis may paradoxically worsen hypocalcemia—a 0.1-unit increase in pH decreases ionized calcium by approximately 0.05 mmol/L. 4