Medication Summary
Treatment depends upon the level of magnesium and the presence of symptoms. In patients with mildly increased levels, simply stop the source of magnesium. In patients with higher concentrations or severe symptoms, other treatments are necessary. Calcium should be reserved for patients with life-threatening symptoms, such as arrhythmia or severe respiratory depression.
Intravenous fluids
Class Summary
Intravenous fluids work by dilution of the extracellular magnesium. Fluids are used with diuretics to promote increased excretion of magnesium by the kidney.
Normal saline or lactated Ringer solution
Both fluids are essentially isotonic, and, while some of their metabolic effects differ, the differences are clinically irrelevant for the purpose of promoting diuresis.
Diuretics
Class Summary
These agents increase excretion of magnesium by the kidney.
Furosemide (Lasix)
Acts at loop of Henle to promote loss of magnesium in urine.
Mineral supplements
Class Summary
Calcium directly antagonizes the effects of magnesium. Reserved for patients with severe or symptomatic hypermagnesemia.
Calcium gluconate (Kalcinate)
Directly antagonizes neuromuscular and cardiovascular effects of magnesium. The 10% IV solution provides 100 mg/mL of calcium gluconate that equals 9 mg/mL (0.46 mEq/mL) of elemental calcium. One 10 mL ampule contains 93 mg of elemental calcium.
