Electrolyte & Vitamin D Analogue Dosing

Vitamin D and analogues

• Cholecalciferol

• Ergocalciferol

• Calcitriol

• Paricalcitol

• Doxercalciferol

Electrolytes

• NaCl - dosed by mEq of Na.

  • Salt tabs 1 g = 17 mEq Na per tab

  • Liquid 1 mEq/mL compounded suspension, not routinely available

• Cytra-K

  • Powder packets = 30 mEq K per packet (and 30 mEq HCO3)

  • Liquid = 10 mEq K and 10 mEq HCO3 per 5mLs

• Bicitra/Cytra-2 - dosed by mEq of HCO3 (citrate)

  • Liquid 1 mEq Na and 1 mEq HCO3 per mL

• MagOx

• NaPhos

• PhosNaK

Calcium: calcium equivalents calculator

99% of calcium in the body is in the skeleton, 1% in the extracellular fluids and soft tissues

50% of total serum calcium is ionized (active)

8-10% of serum calcium is bound to organic and inorganic acids; ~40% is bound to proteins (primarily albumin)

• IV CaGluc USP 10% [drugbank]

  • 10% = 1 g of CaGluc in 10 mL of water

    • 1 g CaGluc (or 10 mL of 10% CaGluc) contains 93 mg of elemental Ca = 4.65 mEq Ca = 2.325 mmol Ca

      • Elemental calcium per mL: 9.3 mg/mL = 0.465 mEq/mL = 0.2325 mmol/mL

    • Maximum rate: 1.5 mL/min (0.7 mEq/min)

• IV CaCl₂ USP 10%

  • 10% = 1 g of CaCl₂ in 10 mL of water

    • 1 g of CaCl₂ (or 10 mL of 10% CaCl₂) contains 273 mg of elemental Ca = 13.6 mEq Ca = 6.8 mmol Ca

      • Elemental calcium per mL: 27.3 mg/mL = 1.36 mEq/mL = 0.68 mmol/mL

    • Maximum rate: 1.0 mL/min (1.36 mEq/min)

    • 1 g of elemental Ca is about 3.7 g of CaCl₂

  • More effective than IV CaGluc at raising ionized calcium and blood pressure [PMID 12375668, 2246705]

  • Vesicant, requires a central line