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AKA: hypermagnesaemia

Evaluation and management of elevated blood magnesium in pediatric patients


  • Decreased GFR → ↓ filtration and ↓ phosphorus excretion
  • Large intake of magnesium (e.g., antacids, laxatives, IV fluids, maternal intake in newborns)

Excessive magnesium intake

  • Laxative, bowel prep
  • IV fluids
  • Supplementation

Signs and symptoms

  • Usually asymptomatic unless extremely high
  • Loss of deep tendon reflexes (DTRs)
  • Weakness
  • Cardiac dysrhythmias
  • Coma


  • Evaluate history for sources of excessive magnesium intake
  • Labs:
    • Kidney function


  • Reduce intake of magnesium
  • Volume expansion and/or loop diuretics if no improvement despite reduction of intake
  • Administer calcium if severe and/or symptomatic