From the Guidelines
Hypocalcemia, hypomagnesemia, and hypokalemia are complex electrolyte disturbances that can result from various causes, including vitamin D deficiency, hypoparathyroidism, chronic kidney disease, and certain medications, with hypomagnesemia and hypokalemia often stemming from gastrointestinal losses, alcoholism, and poor dietary intake, as noted in studies such as 1 and 1.
Causes of Hypocalcemia
- Hypocalcemia can result from vitamin D deficiency, hypoparathyroidism, chronic kidney disease, pancreatitis, or medications like bisphosphonates and certain anticonvulsants, as seen in patients with 22q11.2 deletion syndrome 1.
- Surgical removal of the parathyroid glands during thyroid surgery is another important cause of hypocalcemia.
Causes of Hypomagnesemia
- Hypomagnesemia often stems from gastrointestinal losses (diarrhea, malabsorption), alcoholism, certain medications (proton pump inhibitors, diuretics, aminoglycosides), diabetic ketoacidosis, or poor dietary intake, as discussed in 1 and 1.
- Magnesium deficiency is common and has been associated with benefit in treating torsades de pointes (TdP), with differing normal values reported, but <1.3 mEq/L is undisputedly low 1.
Causes of Hypokalemia
- Hypokalemia commonly occurs due to inadequate intake, excessive losses through the kidneys (diuretics, hyperaldosteronism), gastrointestinal tract (vomiting, diarrhea), or transcellular shifts (insulin administration, beta-agonists), as noted in various studies.
- These electrolyte abnormalities often coexist and influence each other; for example, hypomagnesemia can cause refractory hypocalcemia and hypokalemia by affecting parathyroid hormone secretion and potassium channel function, as seen in 1 and 1.
Treatment and Management
- Treatment should address the underlying cause while replacing the deficient electrolytes, with severe deficiencies requiring intravenous replacement, and mild to moderate cases often managed with oral supplementation and dietary modifications, as recommended in 1 and 1.
- Regular investigations, including measurements of pH-corrected ionized calcium, magnesium, parathyroid hormone, and creatinine concentrations, are recommended, along with daily calcium and vitamin D supplementation for all adults with 22q11.2DS, and magnesium supplementation for those with hypomagnesemia, as noted in 1.
From the Research
Causes of Hypocalcemia
- Hypoparathyroidism, characterized by impaired secretion of parathyroid hormone (PTH), is a classic cause of chronic hypocalcemia 2
- Disorders that disrupt the metabolism of vitamin D can also lead to chronic hypocalcemia, as vitamin D is responsible for increasing the gut absorption of dietary calcium 2
- Postsurgical hypoparathyroidism is the most frequent cause of hypocalcemia 3
Causes of Hypomagnesemia
- Certain chemotherapies, including cisplatin, cetuximab, eribulin, and ifosfamide, can cause hypomagnesemia as a side effect 4
- Alcoholism is a common cause of hypomagnesemia, often leading to a syndrome of hypomagnesemic hypokalemia and hypocalcemia 5
Causes of Hypokalemia
- Certain chemotherapies, including cisplatin, cetuximab, eribulin, and ifosfamide, can cause hypokalemia as a side effect 4
- Hypomagnesemia can lead to hypokalemia due to inappropriate kaliuresis 5
- Alcoholism is a common cause of hypokalemia, often leading to a syndrome of hypomagnesemic hypokalemia and hypocalcemia 5
Interrelated Electrolyte Abnormalities
- Hypomagnesemia can lead to hypokalemia and hypocalcemia due to various mechanisms, including inappropriate kaliuresis and renal calcium wasting 5
- Patients with hypomagnesemic hypokalemia and hypocalcemia often exhibit multiple interrelated acid-base and electrolyte abnormalities, including respiratory and metabolic alkalosis, and mixed acid-base disorders 5