HypoMagnesemia

 


- Differential Diagnosis:
      - Malabsorption, Steatorrhea, Diarrhea, Laxitive, ETOH/withdrawl, Alcoholism and Cirrhosis, Hyperthyroidism, Aldosteronism, Diuretics,
      - RTA, Acute Pancreatitis Hyperparathyroidism, Hyperalimentation, NG suctioning, Chronic Dialysis, RTA, Hungry Bone syndrome,
      - Hypophosphatemia, Intracellular shifts w/ respiratory acidosis or metabolic acidosis
      - Meds (Cis Platinum, Amphotericin B, Aminoglycosides Cisplatin, Ifosphamide, Insulin, Diuretics; 

- Note that hypoMg may cause hypoK and hypoCa 
- Signs and Symptoms:
       - paresthesia's, hyperreflexia, muscle spasm, & tetany; 
       - may cause chondrocalcinosis

- Rx of HypoMg 

- Prophylaxis or Asymptomatic: ( < 1.4)
    - Mg Oxide 250 mg tabs contains 12.5 mEq (3 to 8 tabs/day to prevent HypoMg)
    - Mg Sulfate: (50% sol. w/ 8.1 mEq per gm)
         - prophylactic dose: 4-12 gm/day given IM/IV in D5W;

- Symptomatic HypoMg:  ( < 1.4)
    - w/ siezures, eclampsia, or arrhythmia's, aggressive Rx is indicated;
         - Mg Sulfate: 3 gm in 30 ml D5W IV over 5 min;
         - if needed dose may be repeated upto 10 gm in 6 hrs;
    - w/ less severe symtoms: 6 gm IV over 3 hrs, then 3 gm q12 hrs;
    - in patients with an arrhythmai but no symptoms consider 2 gm IV;

- Misc:
    - if renal function is normal, as much as 2 mEq/kg body wt. of magnesium can be administered in one day in the face of severe depletion;
    - Mg sulfate (50% solution contains approx 4 mEq of Mg/ml) given IV;
    - try 80 mEq of Mg sulfate (20 ml of 50% solution) to 1 liter over 4-6 hr;
    - if patient is not symptomatic, the infusion should be given over a longer period of time

 




Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Wednesday, September 5, 2012 8:17 pm