Magnesium Imbalances: Causes and Manifestations

Magnesium

  • Roles of Magnesium
    • Coenzyme in metabolism of carbohydrates
    • Required for DNA and protein synthesis
    • Blood glucose control
    • BP regulation
    • Necessary for ATP production
    • Acts directly on myoneural junction
    • Important for normal cardiac function
    • 50% to 60% contained in bone
    • Absorbed in GI tract
    • Excreted by kidneys
  • Hypermagnesemia
    • High serum Mg caused by
      • Increased intake or ingestion of products containing magnesium when renal insufficiency or failure is present
      • Excess IV magnesium administration
    • Manifestations
      • Lethargy
      • Nausea and vomiting
      • Impaired reflexes
      • Muscle paralysis
      • Respiratory and cardiac arrest
      • Urinary retention
      • Flushed, warm skin, especially facial
      • Decreased Pulse, Decreased BP
    • Management
      • Prevention first—restrict magnesium intake in high-risk patients
      • IV CaCl or calcium gluconate if symptomatic
      • Fluids and IV furosemide to promote urinary excretion
      • Dialysis
  • Hypomagnesemia
    • Low serum Mg caused by
      • Prolonged fasting or starvation
      • Chronic alcoholism
      • Fluid loss from gastrointestinal tract
      • Prolonged parenteral nutrition without supplementation
      • Diuretics
      • Hyperglycemic osmotic diuresis
    • Manifestations
      • Hyperactive deep tendon reflexes
      • Muscle cramps
      • Tremors
      • Seizures and confusion
      • Cardiac dysrhythmias
      • Corresponding hypocalcemia and hypokalemia
      • Chvostek’s and Trousseau’s signs
      • Increased Pulse, Increased BP, dysrhythmias
    • Management
      • Treat underlying cause
      • Oral supplements
      • Increase dietary intake
      • Parenteral IV or IM magnesium when severe

Magnesium Imbalances: Causes and Manifestations

Hypermagnesemia (Mg+ >2.5 mEq/L [1.25 mmol/L])

Hypomagnesemia (Mg+ <1.5 mEq/L [0.75 mmol/L])

Cause

  • Renal failure
  • GI tract fluid losses (e.g., diarrhea, NG suction)
  • IV administration of magnesium, especially for treatment of eclampsia
  • Chronic alcoholism
  • Tumor lysis syndrome
  • Malabsorption syndromes
  • Hypothyroidism
  • Prolonged malnutrition
  • Metastatic bone disease
  • Increased Urine output
  • Adrenal insufficiency
  • Hyperglycemia
  • Antacids, laxatives
  • Proton pump inhibitor therapy

Share:

More Posts

Aspirin overdose

Aspirin is a nonsteroidal anti-inflammatory drug (NSAID) used to relieve mild to moderate aches and pains, swelling, and fever. Aspirin overdose occurs when someone accidentally

Pulmonary edema

Pulmonary edema is an abnormal buildup of fluid in the lungs. This buildup of fluid leads to shortness of breath. Causes Pulmonary edema is often