From the Guidelines
Magnesium replacement through a jejunostomy (J) tube is best accomplished using liquid magnesium preparations, with a recommended starting dose of 200-400 mg of elemental magnesium daily, divided into 2-3 doses, as supported by the most recent and highest quality study 1.
Key Considerations
- Magnesium oxide should be avoided as it requires stomach acid for absorption, which may not be present in patients with a J tube.
- When administering, flush the tube with 30 mL of water before and after giving the medication, and dilute the magnesium solution with 30-60 mL of water to reduce gastrointestinal irritation, as suggested by 1.
- For severe deficiency, higher doses of 400-800 mg daily may be needed initially, with monitoring of serum magnesium levels every 3-5 days until normalized, as recommended by 1.
- Long-term maintenance typically requires 200-300 mg daily, with regular monitoring of magnesium levels, renal function, and other electrolytes (especially potassium and calcium) during replacement therapy, as emphasized by 1.
Important Factors to Monitor
- Serum magnesium levels
- Renal function
- Potassium and calcium levels
- Gastrointestinal irritation, such as diarrhea and abdominal cramping
Additional Recommendations
- Patients with a J tube should be encouraged to drink a glucose-saline replacement solution (sodium 90 mmol/l or more) to reduce stomal losses of sodium, as recommended by 1.
- Hypomagnesaemia is common in patients with a jejunostomy and should be treated by correcting sodium depletion, oral or intravenous magnesium supplements, and occasionally with oral 1 alpha hydroxycholecalciferol, as suggested by 1.
From the Research
Magnesium Replacement Guidelines
There are no specific guidelines provided in the studies for magnesium replacement via jejunostomy (J) tube.
Alternative Administration Methods
- Intravenous magnesium administration is discussed in several studies, including 2 and 3, which compare the efficacy of intravenous and oral magnesium replacement in hospitalized patients.
- Subcutaneous magnesium administration is mentioned in 4 as a potential method for long-term management of hypomagnesemia in ambulatory patients.
- Oral magnesium replacement is compared to intravenous administration in 3, which found that intravenous administration resulted in greater and more rapid elevations in serum magnesium concentrations.
General Magnesium Replacement Considerations
- The route, dose, timing of administration, and formulation of magnesium can differ for each indication, as noted in 5.
- Magnesium balance and the factors that affect magnesium flux during dialysis are discussed in 6, which highlights the importance of measuring plasma magnesium concentration on a regular basis and adjusting dialysate magnesium concentration to maintain plasma magnesium concentration within the normal range.