Neonatal Drug Therapy Manual

Magnesium Sulfate

Disclaimer: Official controlled document is the CHEO and Ottawa Hospital online copy. It is the responsibility of user to ensure that any paper copy version is the same as the online version before use.

Electrolyte Supplement
Original Date: 
June 1996
Revised Date: 
May 2013
  • Hypomagnesemia
  • IV intermittent infusion: over 2 - 4 hours
  • 25 - 50 mg MgSO4/kg/dose every 8 - 12 hours for 2 - 3 doses
  • Equivalent to 0.1 - 0.2 mmol/kg/dose of elemental Mg
Side Effects: 
  • CVS: hypotension
  • Endocrine and metabolic: hypermagnesemia (monitor CNS depression and decreased muscle tone)
Parameters to Monitor: 
  • Serum Mg
  • BP
Reconstitution and Stability: 


  • Magnesium Sulfate 40 mg/mL (Equivalent to 0.16 mmol/mL) - prefilled syringe made by Pharmacy


  • Magnesium 2 mmol/mL
    • Add 0.8 mL (1.6 mmol) to 9.2 mL of 0.9% NaCl
    • Final concentration: 0.16 mmol/mL of elemental Mg = 40 mg/mL of magnesium sulfate

- Solutions Compatible: D5W, 0.9% NaCl, dextose-saline combinations

- Y-site Compatible: ampicillin, cefazolin, cefotaxime, dobutamine, gentamicin, KCl, morphine, vancomycin


- Taketomo CK, Hodding JH, Kraus DM. Pediatric Dosage Handbook 19th Edition. Hudson: Lexi-Comp Inc.; 2012.

- Trissel LA. Handbook on Injectable Drugs. 16th Editions.  Bethesda: American Society of health-System Pharmacists; 2011

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