From the Guidelines
Hypomagnesemia treatment involves oral or intravenous magnesium supplementation depending on severity, with the most recent guidelines from 2020 recommending IV magnesium for cardiotoxicity and cardiac arrest from severe hypomagnesemia 1. For mild to moderate deficiency, oral magnesium supplements like magnesium oxide are recommended, with a dose of 12–24 mmol daily, given as gelatine capsules of 4 mmol magnesium oxide (160 mg of MgO) at night to improve absorption 1. Key considerations in treatment include:
- Severity of deficiency: mild to moderate (serum magnesium 1.2-1.7 mg/dL) vs. severe (below 1.2 mg/dL)
- Presence of symptoms: seizures, arrhythmias, or cardiac arrest
- Underlying cause: chronic conditions like alcoholism, malabsorption, or certain medications
- Kidney function: magnesium is primarily excreted by the kidneys, so assessment is crucial before treatment Treatment duration and ongoing supplementation needs are determined by the underlying cause, with regular serum magnesium checks necessary for monitoring 1. Addressing underlying causes, such as discontinuing offending medications or controlling diabetes, is essential for long-term management, as magnesium plays a crucial role in over 300 enzymatic reactions in the body, including neuromuscular function and cardiac electrical activity 1.
From the FDA Drug Label
In the treatment of mild magnesium deficiency, the usual adult dose is 1 g, equivalent to 8. 12 mEq of magnesium (2 mL of the 50% solution) injected IM every six hours for four doses (equivalent to a total of 32.5 mEq of magnesium per 24 hours). For severe hypomagnesemia, as much as 250 mg (approximately 2 mEq) per kg of body weight (0. 5 mL of the 50% solution) may be given IM within a period of four hours if necessary. Alternatively, 5 g (approximately 40 mEq) can be added to one liter of 5% Dextrose Injection, USP or 0. 9% Sodium Chloride Injection, USP for slow IV infusion over a three-hour period.
- The treatment for hypomagnesemia (low magnesium levels) involves administering magnesium sulfate.
- The dosage of magnesium sulfate varies depending on the severity of the deficiency:
- For mild magnesium deficiency, the usual adult dose is 1 g (8.12 mEq) injected IM every six hours for four doses.
- For severe hypomagnesemia, the dose can be as high as 250 mg (approximately 2 mEq) per kg of body weight given IM within a period of four hours, or 5 g (approximately 40 mEq) added to one liter of 5% Dextrose Injection or 0.9% Sodium Chloride Injection for slow IV infusion over a three-hour period 2.
From the Research
Treatment for Hypomagnesemia
The treatment for hypomagnesemia (low magnesium levels) depends on the severity of the condition and the presence of symptoms.
- Asymptomatic patients with hypomagnesemia can be treated with oral magnesium supplements 3.
- Parenteral magnesium should be reserved for symptomatic patients with severe magnesium deficiency (< 1.2 mg/dL) 3, 4.
- When urgent correction of hypomagnesemia is required, as with myocardial ischemia, post cardiopulmonary bypass, and torsades de pointes, intravenous or intramuscular magnesium sulfate should be used 4.
- Oral magnesium preparations are available for chronic use 4.
Considerations for Treatment
Before administering any magnesium supplementation, it is essential to establish adequate renal function 3.
- The choice of treatment also depends on the underlying cause of hypomagnesemia, such as gastrointestinal losses or renal losses 3, 4.
- Laboratory tests, including measurement of fractional excretion of magnesium and urinary calcium-creatinine ratio, can help determine the likely cause of hypomagnesemia and guide treatment 3, 5.