What is the recommended magnesium citrate dosage? How does it interact with other medications? What are the potential side effects? Get all the answers in this comprehensive guide.

Magnesium Citrate Dosage and Usage

Magnesium citrate is a commonly used supplement and laxative. The recommended dosage varies depending on the intended use:

Nutritional Supplementation

• 19-30 years: Men, 400 mg/day; women, 310 mg/day; pregnant women (≤50 years), 350 mg/day; breastfeeding women (≤50 years), 310 mg/day
• >30 years: Men, 420 mg/day; women, 320 mg/day; pregnant women (≤50 years), 360 mg/day; breastfeeding women (≤50 years), 320 mg/day

Constipation/Laxative Use

• Adults: 195-300 mL PO in single daily dose or in divided doses with full glass of water
• Alternative: 2-4 tablets PO at bedtime
• Children 2-6 years: 60-90 mL PO once or divided doses; not to exceed 90 mL/24hr
• Children 6-12 years: 90-210 mL in single dose or in divided doses with full glass of water
• >12 years: 195-300 mL PO in single daily dose or in divided doses with full glass of water; alternatively, may administer 2-4 tablets PO at bedtime

Acid Indigestion

• 1 tablet twice daily or as directed by healthcare provider

Magnesium Citrate Interactions

Magnesium citrate can interact with various medications. Here are some of the key interactions to be aware of:

Contraindicated or Serious Interactions

• Baloxavir marboxil: Magnesium citrate decreases the level or effect of baloxavir marboxil by cation binding in the GI tract. Avoid or use an alternate drug.
• Demeclocycline, doxycycline, minocycline, oxytetracycline, tetracycline: Magnesium citrate decreases the levels of these drugs by inhibiting GI absorption. Avoid or use an alternate drug.
• Dolutegravir: Magnesium citrate decreases the level or effect of dolutegravir by cation binding in the GI tract. Avoid or use an alternate drug.
• Eltrombopag: Magnesium citrate decreases the levels of eltrombopag by inhibiting GI absorption. Contraindicated, separate administration by at least 4 hours.
• Potassium phosphates, IV: Magnesium citrate decreases the effects of IV potassium phosphates by cation binding in the GI tract. Avoid or use an alternate drug.

Monitor Closely Interactions

• Bictegravir: Magnesium citrate decreases the level or effect of bictegravir by cation binding in the GI tract. Modify therapy and monitor closely.
• Cabotegravir: Magnesium citrate decreases the level or effect of cabotegravir by cation binding in the GI tract. Modify therapy and monitor closely.
• Ciprofloxacin: Magnesium citrate decreases the levels of ciprofloxacin by inhibiting GI absorption. Use caution and monitor closely.
• Deferiprone: Magnesium citrate decreases the levels of deferiprone by enhancing GI absorption. Modify therapy and monitor closely.

Magnesium Citrate Safety and Side Effects

Magnesium citrate is generally well-tolerated, but it can cause some side effects, especially when used as a laxative:

Common Side Effects

• Diarrhea
• Abdominal cramps
• Nausea
• Vomiting

Serious Side Effects

• Dehydration
• Electrolyte imbalances (e.g., low potassium or sodium)
• Kidney problems (in those with pre-existing kidney disease)

To maintain potency and palatability, magnesium citrate should be refrigerated. Patients with certain medical conditions, such as intestinal blockage, severe stomach or bowel problems, or heart disease, should consult a healthcare provider before using magnesium citrate.

Dosage Forms and Strengths

Magnesium citrate is available in the following dosage forms and strengths:

• Liquid: 290 mg/5 mL
• Tablet: 100 mg (elemental magnesium)

Conclusion

In summary, the recommended magnesium citrate dosage varies depending on the intended use, such as nutritional supplementation, constipation/laxative, or acid indigestion. It is important to be aware of potential interactions, especially with certain medications, and to monitor for side effects, particularly when using it as a laxative. Proper dosing and administration, as well as consulting a healthcare provider, are key to ensuring the safe and effective use of magnesium citrate.