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Generic Name: magnesium citrate
Drug Class: Laxatives, saline
What is magnesium citrate, and what is it used for?
Magnesium citrate is a laxative used to relieve constipation and acid indigestion, to clear the bowels before a colonoscopy procedure, and as a dietary supplement for magnesium deficiency. Magnesium citrate is derived from combining the mineral magnesium and citric acid. Magnesium citrate is available over-the-counter in the United States.
Magnesium citrate is an osmotic laxative that draws water into the colon and makes the stools soft and bulky, facilitating bowel movement. The uses of magnesium citrate include:
Adult:
- Nutritional supplementation
- Constipation
- Acid indigestion
- Bowel preparation before colonoscopy (off-label)
Pediatric:
Warnings
- Use magnesium citrate only occasionally for constipation; prolonged use can cause serious side effects
- Do not take magnesium citrate if you are on a low-sodium diet
- Do not take if you are allergic to magnesium citrate or any of its components
- Discontinue magnesium citrate and consult your health provider if:
- Bowel movement does not occur after use
- Rectal bleeding develops
- Avoid taking magnesium citrate if you have any of the following conditions:
- Electrolyte imbalance
- Dehydration
- Heart block or damage to the heart muscle (myocardial damage)
- Kidney failure
- Fecal impaction
- Rectal fissures
- Intestinal obstruction or perforation
- Any acute abdominal condition requiring surgery (acute surgical abdomen) including appendicitis
- Magnesium citrate should be administered under physician’s supervision in patients who:
- Have kidney dysfunction
- Are on sodium or magnesium-restricted diet
- Have nausea, vomiting and abdominal pain with sudden change in bowel habits persisting over 2 weeks
- Use magnesium citrate with caution if you have myasthenia gravis or any other neuromuscular disease
What are the side effects of magnesium citrate?
Common side effects of magnesium citrate include:
- Nausea
- Vomiting
- Gas formation (flatulence)
- Abdominal cramping
- Diarrhea
- High blood magnesium levels (hypermagnesemia)
- Electrolyte imbalance
This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug.
Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.
What are the dosages of magnesium citrate?
Liquid
- 290 mg/5ml
Tablet
- 100 mg (elemental)
Adult:
Nutritional Supplementation
19 to 30 years old:
- Men – 400 mg/day
- Women – 310 mg/day
- Pregnant women younger than 50 years old: 350 mg/day
- Breastfeeding women younger than 50 years old: 320 mg/day
Over 30 years old:
- Men – 420 mg/day
- Women – 320 mg/day
- Pregnant women younger than 50 years old: 360 mg/day
- Breastfeeding women younger than 50 years old: 320 mg/day
Constipation/Bowel Evacuation:
- 195-300 ml orally in a single daily dose or divided doses with a full glass of water
- Alternatively, 2-4 tablets orally at bedtime
Acid Indigestion:
- 1 tablet twice daily or as directed by a healthcare provider
Pediatric:
Constipation/Bowel Evacuation:
- Children under 2 years old: Safety and efficacy not established
- Children 2-6 years old: 60-90 ml orally once or in divided doses, not to exceed 90 mg/24 hours
- Children 6-12 years old: 90-120 ml in a single dose or divided doses with a full glass of water
- Children over 12 years old: 195-300 ml orally in a single dose or divided doses with a full glass of water, alternatively, may administer 2-4 tablets orally at bedtime
Dosing Considerations
- Should be refrigerated to maintain potency and palatability
Overdose
Overdose may lead to dehydration, electrolyte imbalance and decrease in blood volume (hypovolemia), which should be treated with symptomatic and supportive care.
What drugs interact with magnesium citrate?
Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.
- Magnesium citrate has no known severe interactions with any drugs.
- Serious interactions of magnesium citrate include:
- demeclocycline
- dolutegravir
- doxycycline
- eltrombopag
- lymecycline
- minocycline
- oxytetracycline
- potassium phosphates, intravenously
- tetracycline
- Moderate interactions of magnesium citrate include:
- ciprofloxacin
- deflazacort
- fleroxacin
- levofloxacin
- moxifloxacin
- norfloxacin
- ofloxacin
- penicillamine
- sodium phosphates, intravenously
- vitamin D
- Magnesium citrate has mild interactions with at least 44 different drugs.
The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.
It is important to always tell your doctor, pharmacist, or health care provider of all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or health care provider if you have any questions about the medication.
Pregnancy and breastfeeding
- Occasional use of magnesium citrate is generally safe in pregnant and nursing mothers.
- The first line of therapy for constipation during pregnancy is to increase dietary fiber and water intake, and moderate amounts of daily exercise. Magnesium citrate may be used if these are ineffective, occasionally or for a short period, in order to avoid dehydration or electrolyte imbalances.
What else should I know about magnesium citrate?
- Take magnesium citrate exactly as per the package instructions
- Do not take magnesium citrate for regular bowel movement; use only for occasional constipation
- Magnesium citrate usually causes a bowel movement within 30 minutes to 6 hours after taking it; if bowel movement does not occur or there is blood in stool, discontinue magnesium citrate and seek medical help
- Keep out of reach of children
- Refrigerate it to make it more palatable and potent
