Dosing and uses of Magnesium citrate
Adult dosage forms and strengths
liquid
- 290mg/5mL
tablet
- 100mg (elemental)
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/Bowel Evacuation
195-300 mL PO in single daily dose or in divided doses with full glass of water
Alternative: 2-4 tablets PO at bedtime
Acid Indigestion
1 tablet twice daily or as directed by healthcare provider
Pediatric dosage forms and strengths
liquid
- 290mg/5mL
tablet
- 100mg (elemental)
Constipation/Bowel Evacuation
<2 years: Safety and efficacy not established
2-6 years: 60-90 mL PO once or divided doses; not to exceed 90 mL/24hr
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
Magnesium citrate adverse (side) effects
Frequency not defined
Abdominal cramping
Diarrhea
Electrolyte imbalance
Hypermagnesemia
Gas formatioin
Nausea/vomiting
Warnings
Contraindications
Low sodium diet
Cautions
Use caution in renal insufficiency or magnesium-restricted diet
For occasional use only in treatment of constipation
Use with caution in patients with myasthenia gravis or other neuromuscular disease
Should be refrigerated to maintain potency and palatability
Avoid use in renal failure, existing electrolyte imbalance, appendicitis or acute surgical abdomen, myocardial damage or heart block, fecal impaction or rectal fissures, intestinal obstruction or perforation, dehydration
Pregnancy and lactation
Pregnancy category: A
Lactation: Use in nursing mothers appears to be safe
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Magnesium citrate
Mechanism of action
Increases peristaltic activity of the colon; promotes bowel evacuation by causing osmotic retention of fluid
Absorption
15-30% absorbed
Onset: 0.5-6 hr or less
Elimination
Excretion: Urine (mainly)
