From the Guidelines
For treating hypomagnesemia with oral medications that don't cause diarrhea, magnesium oxide is a recommended option, as it has been shown to not increase reports of diarrhea compared to placebo 1.
Key Considerations
- Magnesium oxide can be taken at a dose of 500 mg/d to 1 g/d, which is often used in clinical practice, although the dose used in trials was 1.5 g/d 1.
- The bioavailability and clinical efficacy of other formulations of magnesium, such as citrate, glycinate, lactate, and malate, are unknown for this specific use 1.
- Systemic regulation of magnesium levels is maintained by renal excretion, and hypermagnesemia is more likely to occur in individuals with significant renal impairment, so magnesium supplements should be avoided in those with a creatinine clearance of <20 mg/dL 1.
Administration and Monitoring
- When taking magnesium oxide supplements, it's best to divide the doses throughout the day and take them with food to improve tolerance.
- Treatment duration depends on the severity of deficiency and underlying cause, typically continuing for several weeks with regular monitoring of serum magnesium levels.
- Starting with a lower dose and gradually increasing can help minimize gastrointestinal effects while restoring magnesium levels.
Comparison with Other Options
- Other studies suggest that magnesium oxide can be given at night when intestinal transit is assumed to be slowest, allowing for more time for absorption 1.
- However, the most recent and highest quality study recommends magnesium oxide as a first-line option due to its efficacy, tolerability, availability, and low cost 1.
From the FDA Drug Label
ACTIVE INGREDIENT Magnesium Glycinate: ~93.75% The FDA drug label does not answer the question.
From the Research
Treatment of Hypomagnesemia with Oral Medications
To treat hypomagnesemia with oral medications that do not cause diarrhea, it is essential to consider the various options available.
- Magnesium oxide and magnesium citrate are commonly used oral magnesium supplements, but they can cause gastrointestinal side effects, including diarrhea 2.
- However, there are other forms of magnesium that may be better tolerated, such as magnesium glycinate, magnesium L-threonate, and magnesium malate.
- These forms of magnesium are less likely to cause diarrhea and may be a good option for patients who experience gastrointestinal side effects with other forms of magnesium.
Drug-Induced Hypomagnesemia
Certain medications, such as proton pump inhibitors (PPIs), diuretics, and antibiotics, can cause hypomagnesemia by increasing renal magnesium loss or interfering with magnesium absorption 3, 4.
- In patients taking these medications, it is essential to monitor magnesium levels and consider supplementation if necessary.
- Withdrawal of the offending medication may also be necessary to treat hypomagnesemia, as seen in a case report where a patient with symptomatic hypomagnesemia due to PPI therapy was managed by withdrawing the PPI and replacing magnesium and calcium 2.
Diagnosis and Treatment of Hypomagnesemia
Hypomagnesemia is a prevalent condition that can be caused by various factors, including insufficient magnesium intake, increased gastrointestinal or renal loss, or redistribution from extracellular to intracellular compartments 5, 4.
- Laboratory tests, such as total serum magnesium measurement, can be used to diagnose hypomagnesemia.
- Treatment of hypomagnesemia typically involves magnesium supplementation, and the choice of supplement and dosage will depend on the severity of the condition and the presence of any underlying medical conditions.