Clarification Required: The Dose of 4000 grams is Likely an Error
The question asks about 4000 grams of slow-release magnesium, which would be a lethal dose—this is almost certainly a typographical error and likely means 400 mg or 4 grams.
If the Question is About 400 mg of Slow-Release Magnesium
400 mg of elemental magnesium from slow-release magnesium oxide is approximately equivalent to 10 mmol of magnesium. 1
Understanding Magnesium Dosing Conversions
- Magnesium oxide contains approximately 60% elemental magnesium 1
- Standard magnesium oxide capsules typically contain 4 mmol (160 mg) of elemental magnesium 1, 2
- 400 mg of elemental magnesium = approximately 10 mmol = 2.5 standard capsules 1
Clinical Context for This Dose
- For chronic idiopathic constipation, typical doses range from 400-500 mg daily of magnesium oxide 1
- For hypomagnesemia treatment, oral magnesium oxide is typically given as 12-24 mmol daily (480-960 mg elemental magnesium) 1, 2
- The recommended daily allowance is 320 mg for women and 420 mg for men 2
If the Question is About 4 grams (4000 mg) of Magnesium
4 grams of elemental magnesium would be approximately 100 mmol, which is an extremely high and potentially dangerous oral dose. 1
Safety Considerations
- The maximum safe IV dose is typically 40 grams per 24 hours for eclampsia treatment with careful monitoring 1
- For IV magnesium sulfate in cardiac arrest or torsades de pointes, the standard dose is 1-2 grams (approximately 4-8 mmol) 3, 1
- Oral doses above 1,000-1,500 mg daily have been studied but no clear maximum has been established 1
Critical Warning
- Caution is advised when using magnesium supplements in patients with renal insufficiency, as magnesium accumulation can lead to life-threatening hypermagnesemia 1, 2
- Avoid magnesium supplementation if creatinine clearance is less than 20 mL/min 2
- Common side effects include diarrhea, abdominal distension, and gastrointestinal intolerance 2
Please clarify the intended dose, as 4000 grams would represent approximately 1,000 times the typical daily supplementation dose and would be incompatible with life.