From the Guidelines
The treatment for hypomagnesemia involves magnesium replacement therapy, which can be administered orally or intravenously depending on severity, with a preference for oral administration of organic salts like magnesium citrate or magnesium glycinate, as they have higher bioavailability than magnesium oxide or hydroxide 1.
Key Considerations
- For mild to moderate deficiency, oral supplementation is typically recommended, with doses divided into 2-3 times a day to improve tolerance and absorption.
- The choice of magnesium salt is important, with organic salts like magnesium citrate or magnesium glycinate preferred over magnesium oxide or hydroxide due to their higher bioavailability 1.
- In cases of severe deficiency or when oral intake is not possible, intravenous magnesium sulfate may be used, often as 1-2 grams given over 15-30 minutes for acute treatment, followed by additional doses as needed based on serum levels.
- Patients with renal impairment require dose adjustments to prevent toxicity, and monitoring of serum magnesium levels, kidney function, and signs of hypermagnesemia is crucial during treatment.
Underlying Cause Identification
- Identifying and addressing the underlying cause of magnesium deficiency is essential, whether it's medication-induced (diuretics, proton pump inhibitors), malabsorption, alcoholism, or endocrine disorders.
- Correction of water and sodium depletion, as well as reduction of excess lipid in the diet, may also be necessary to prevent secondary hyperaldosteronism and promote magnesium balance 1.
Monitoring and Adjustment
- Monitoring of serum magnesium levels and adjustment of supplementation doses is necessary to maintain optimal levels, with a target level of >0.6 mmol/l considered reasonable 1.
- Dividing supplementation into multiple doses throughout the day can help maintain steady plasma levels and prevent large variations, which may be detrimental to the patient 1.
From the Research
Hypomagnesemia Treatment
The treatment for hypomagnesemia (low magnesium levels) depends on the severity and cause of the condition.
- Asymptomatic patients can be treated with oral magnesium supplements 2.
- Parenteral magnesium should be reserved for symptomatic patients with severe magnesium deficiency (< 1.2 mg/dL) 2.
- The mode of correction (oral or intravenous) depends on the etiology, severity, and clinical consequences of hypomagnesemia 3.
- Establishment of adequate renal function is required before administering any magnesium supplementation 2.
Diagnosis and Clinical Approach
To determine the likely cause of hypomagnesemia, the following steps can be taken:
- Measure fractional excretion of magnesium and urinary calcium-creatinine ratio 2.
- A fractional excretion above 2% in a subject with normal kidney function indicates renal magnesium wasting 2.
- Patients with advanced diseases are exposed to many causes of hypomagnesaemia, and measuring magnesium levels in the blood is important 4.
Clinical Features and Management
Manifestations of magnesium deficiency include:
- Alterations in calcium, phosphate, and potassium homeostasis 5.
- Cardiac disorders such as malignant ventricular arrhythmias refractory to conventional therapy 5.
- Neuromuscular and neuropsychiatric disorders 5.
- Nonspecific symptoms including pain that is difficult to control 4. Magnesium has its indication in patients with:
- Torsade de pointes 6.
- Digoxin-induced arrhythmia or life-threatening ventricular arrhythmias 6.
- Pre-eclampsia in pregnant women, as it decreases the risk of eclamptic seizures by half compared with placebo 6.