Magnesium sulfate

See critical care quick reference for drug doses by weight.


Adult Dosing

  • Loading dose = 1-2gm in 10mL D5W over 1-2min (cardiac arrest)
  • Loading dose = 1-4gm in 50-100 D5W over 20-60min (spontaneous circulation)


  • Initial: 4 g magnesium sulfate 50% solution (400mg elemental magnesium) to a 10% or 20% solution and give IV over 3 to 4 minutes OR 5mg IM in each buttock
  • Maintenance: 1 to 2 g/hr IV until paroxysms cease

Pediatric Dosing

  • Torsades: 25 to 50mg/kg rapid infusion over several minutes


  • 25-50mg/kg IV x 1

See critical care quick reference for drug doses by weight.

Special Populations

  • Pregnancy Rating: D (despite being drug of choice for eclampsia!)
  • Lactation: infant risk minimal
  • Renal Dosing: for severe renal impairment, max dose 20g/48 hours
    • Adult
    • Pediatric
  • Hepatic Dosing
    • Adult
    • Pediatric



  • Allergy to class/drug

Adverse Reactions



  • Half-life:
  • Onset of action = Immediate
  • Duration of action = 30min
  • Metabolism:
  • Excretion: Renal

Mechanism of Action

  • Increases vasomotor tone
  • Prolongs AV conduction; prolongs refractoriness

See Also


    This article is issued from Wikem. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.