Calcium gluconate

General

• Type: Electrolyte
• Dosage Forms: injectable solution, tablet, capsule
• Dosage Strenths: injectable solution: 100mg/mL; tablet: 50, 500, 650mg; capsule: 500mg
• Routes of Administration: PO, IV
• Common Trade Names:

Adult Dosing

• Calcium Supplementation
  • 19-50 years old: 1000mg/day PO (divided q8-12hr)
  • >50 years old: 1200mg/day PO (divided q8-12hr)
  • Pregnant or breastfeeding patient: 1000mg/day PO (divided q8-12hr)
• Hypocalcemia
  • Mild (Calcium 1-1.2 mmol/L)
    • 1-3 g/day PO in divided doses
    • 1-2 g IV over 2 hours
  • Severe (Calcium < 1 mmol/L)
    • without seizure or tetany: 0.5mg/kg/hr IV, may be increased to 2mg/kg/hr
    • Hypocalcemic tetany:
      • 100-300mg elemental calcium (~3g calcium gluconate) IV over 5-10 min
      • Followed by continuous IV infusion at 0.5mg/kg/hr
• Calcium channel blocker toxicity: 3g IV (30-60mL of 10% soln)
• Beta blocker toxicity: 3g IV (30-60mL of 10% soln)
• Hyperkalemia: Give 10ml of a 10% solution over 10 mins
• Hydrofluoric acid toxicity:
  • 25ml 10% calcium gluconate mixed with 75ml water soluble lubricant applied topically
  • In severe cases, can infuse 10ml 10% calcium gluconate mixed in 40mL of D5W through arterial catheter over 4 hours

Pediatric Dosing

• Hypocalcemia
  • Children: 200 to 500 mg IV (slow injection)
  • Infants: up to 200 mg IV (slow injection
• Seizure due to hypocalcemia: 10% calcium gluconate IV 0.3 mL/kg over 5-10min

Special Populations

• Pregnancy Rating: C
• Lactation risk: Use with caution
• Renal Dosing:
  • CrCl less than 25 mL/min, base dosing on serum calcium levels
  • ESRD: if on HD, may need dose reduction
• Hepatic Dosing: No adjustment

Contraindications

• Hypersensitivity
• Hypercalcemia
• Ventricular fibrillation
• Digoxin toxicity (known or suspected)
• Neonates receiving ceftriaxone sodium injection

Adverse Reactions

Serious

• Bradycardia, vasodilation, hypotension, MI, cardiac arrest
• Tissue necrosis (due to extravasation)
• Urolithiasis
• Prostate cancer

Common

• Constipation, abdominal bloating, flatulence
• Headache

Pharmacology

• Half-life:
• Metabolism:
  • Absorption requires Vitamin D
  • Absorption is increased with acidic condition; thus, administer 1-2 hr after meals
  • ~45% protein bound (primarily to albumin)
• Excretion: feces as unabsorbed calcium salt (80%), urine (20%)

Mechanism of Action

• Bone mineral component; cofactor in enzymatic reactions, essential for neurotransmission, muscle contraction, and many signal transduction pathways.

See Also

• Calcium chloride
• Hypocalcemia