From the Guidelines
Hypermagnesemia is primarily caused by impaired kidney function, as the kidneys are responsible for excreting excess magnesium, and excessive intake of magnesium-containing medications, particularly in people with compromised kidney function. The most common causes include advanced chronic kidney disease, acute kidney injury, and end-stage renal disease. Excessive intake of magnesium-containing medications is another significant cause, particularly in people with compromised kidney function. These medications include magnesium-containing antacids, laxatives (like milk of magnesia), certain enemas, and intravenous magnesium sulfate used to treat preeclampsia or eclampsia. Other causes include adrenal insufficiency (Addison's disease), hypothyroidism, lithium toxicity, and tumor lysis syndrome. Rhabdomyolysis can also lead to hypermagnesemia as damaged muscle cells release magnesium into the bloodstream. In rare cases, familial hypocalciuric hypercalcemia can cause elevated magnesium levels.
According to the 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1, administration of calcium may be considered during cardiac arrest associated with hypermagnesemia. The condition is particularly dangerous because magnesium has depressant effects on the nervous system and cardiovascular function, potentially leading to muscle weakness, decreased reflexes, respiratory depression, cardiac arrhythmias, and hypotension in severe cases. Key causes to consider include:
- Advanced chronic kidney disease
- Acute kidney injury
- End-stage renal disease
- Excessive intake of magnesium-containing medications, such as magnesium-containing antacids, laxatives, certain enemas, and intravenous magnesium sulfate
- Adrenal insufficiency (Addison's disease)
- Hypothyroidism
- Lithium toxicity
- Tumor lysis syndrome
- Rhabdomyolysis
- Familial hypocalciuric hypercalcemia
It is essential to identify and address the underlying cause of hypermagnesemia to prevent severe complications and improve patient outcomes.
From the Research
Possible Causes of Hypermagnesemia
- Excessive magnesium intake, which can occur through the use of magnesium-containing supplements, cathartics, or antacids 2, 3, 4, 5
- Reduced renal excretion, often associated with impaired kidney function or renal disease 2, 4, 6
- Intestinal obstruction or constipation, particularly in individuals taking magnesium oxide (MgO) 3
- Use of laxatives or Epsom salts, which are high in magnesium sulfate 5
- Advanced chronic kidney disease (CKD), where the kidney's ability to regulate magnesium levels is compromised 6
- Hemodialysis or peritoneal dialysis with high magnesium dialysate concentrations 6
Patient-Specific Factors
- Age, with older adults being more susceptible to hypermagnesemia due to decreased renal function or polypharmacy 2
- Underlying medical conditions, such as cerebral hemorrhage, mental retardation, or end-stage renal disease 2
- Medication use, including constipation medicines or supplements containing magnesium 3