- Normal magnesium is 1.7-2.3 mg/dl.
- Usually associated with ulcerative colitis, diarrhea, pancreatitis, laxative abuse, inadequate intake, alcohol use, diuretic use, often occurs concurrently with hypocalcemia and hypokalemia.
- Symptoms include tetany, twitching, seizures, arrhythmias, hypertension, and sudden cardiac death.
- Oral supplements
- Symptomatic patients treated with 1-4 mg by IV infusion (1 g/hour to avoid hypotension and increased renal excreation). Can be pushed in emergencies.
- Reduce dose by half in renal insufficiency.
- Usually associated with CKD.
- Symptoms include nausea, vomiting, bradycardia, hypotension, heart block, asystole, respiratory failure, and death.
- Discontinue all magnesium-containing medications
- Asymptomatic people with normal kidney function get 0.9% saline and loop diuretics.
- Symptomatic patients get 100-200 mg of elemental calcium, usually calcium gluconate (see calcium section for gluconate vs chloride) IV over 5-10 minutes (the actions of magnesium in neuromuscular and cardiac function are antagonized by calcium).
- May need hemodialysis in kidney disease.