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Magnesium Citrate

Medically reviewed by Drugs.com. Last updated on Nov 15, 2020.

Pronunciation

(mag NEE zhum SIT rate)

Index Terms

  • Citrate of Magnesia
  • Mag Citrate

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Solution, Oral:

Citroma: 1.745 g/30 mL (296 mL) [contains polyethylene glycol, saccharin sodium; lemon flavor]

Citroma: 1.745 g/30 mL (296 mL) [low sodium; contains alcohol, usp, benzoic acid, disodium edta]

Citroma: 1.745 g/30 mL (296 mL) [low sodium; contains fd&c red #40, saccharin sodium; cherry flavor]

Citroma: 1.745 g/30 mL (296 mL) [low sodium; contains saccharin sodium; lemon flavor]

GoodSense Magnesium Citrate: 1.745 g/30 mL (296 mL) [contains polyethylene glycol, saccharin sodium]

GoodSense Magnesium Citrate: 1.745 g/30 mL (296 mL) [low sodium; contains alcohol, usp, fd&c red #40, saccharin sodium]

GoodSense Magnesium Citrate: 1.745 g/30 mL (296 mL) [low sodium; contains saccharin sodium; lemon flavor]

GoodSense Magnesium Citrate: 1.745 g/30 mL (296 mL) [saccharin free; contains benzoic acid, disodium edta]

Generic: 1.745 g/30 mL (296 mL)

Tablet, Oral:

Generic: 100 mg

Brand Names: U.S.

  • Citroma [OTC]
  • GoodSense Magnesium Citrate [OTC]

Pharmacologic Category

  • Laxative, Saline
  • Magnesium Salt

Pharmacology

Promotes bowel evacuation by causing osmotic retention of fluid which distends the colon with increased peristaltic activity

Absorption

Oral: Up to 30%

Excretion

Urine (IOM 1997); feces (as unabsorbed drug)

Onset of Action

Laxative effect: Oral solution: 0.5 to 6 hours

Use: Labeled Indications

Occasional constipation: Treatment of occasional constipation

Off Label Uses

Bowel preparation before colonoscopy

Based on the the American Society for Gastrointestinal and Endoscopy (ASGE) guideline for bowel preparation before colonoscopy, routine use of magnesium citrate as a stand-alone colonoscopy preparation is not recommended for routine use due to limited efficacy data and potential toxicity. A randomized, prospective 2-part study supports use of magnesium citrate as an effective and well tolerated low-volume colonoscopy preparation [Berkelhammer 2002].

Contraindications

OTC labeling: When used for self-medication, do not use if on low salt diet

Dosing: Adult

Bowel preparation before colonoscopy (off-label use): Note: This preparation should be avoided in patients with renal impairment, heart failure, decompensated cirrhosis, or baseline electrolyte abnormalities (A-Rahim 2018). There is no standard dosing for administration; the following recommendations are suggested by some experts.

Single-dose, same-day (for afternoon procedures): Oral: 1.5 bottles (450 mL or 15 oz) taken 8 hours prior to procedure, followed by clear liquids (at least three 240 mL glasses) over 2 hours. Four hours prior to the procedure, administer a second 1.5 bottle dose followed by clear liquids (three 240 mL glasses) over 1 hour (A-Rahim 2018).

Split-dose (evening before procedure): Oral: 1 to 1.5 bottles (300 to 450 mL or 10 to 15 oz) in the early evening (ie, between 6 and 8 PM) followed by clear liquids (at least three 240 mL glasses) over 2 hours. Patient should also be given a clear liquid diet the day prior to the procedure. Six hours prior to the colonoscopy, administer a second 1 to 1.5 bottle dose followed by clear liquids (three 240 mL glasses) over 1 hour (ASGE [Saltzman 2015]; A-Rahim 2018).

Laxative: Oral: Solution: 195 to 300 mL given once or in divided doses

Dosing: Geriatric

Refer to adult dosing.

Bowel preparation before colonoscopy (off-label use): The ASGE does not recommend use in the elderly (ASGE [Saltzman 2015]); however, some experts suggest that older patients without comorbidities and who cannot tolerate a higher volume preparation may receive magnesium citrate (A-Rahim 2018).

Dosing: Pediatric

Constipation, occasional: Note: Use of magnesium citrate has generally been replaced with other laxatives (eg, PEG solutions, lactulose) less likely to cause adverse effects (eg, electrolyte disturbances) (Tabbers 2014): Oral solution: Oral:

Children 2 to <6 years: 60 to 90 mL administered as a single dose or in divided doses

Children 6 to <12 years: 100 to 150 mL administered as a single dose or in divided doses

Children ≥12 years and Adolescents: 150 to 300 mL administered as a single dose or in divided doses

Bowel preparation: Limited data available: Oral: Oral Solution: Children >6 years and Adolescents: 4 to 6 mL/kg/day, may administer as a single dose or in divided doses the day before the procedure; maximum daily dose: 300 mL/day (NASPGHAN [Pall 2014])

Administration

Oral: To increase palatability, chill the solution prior to administration. Administer each dose with 8 oz (240 mL) of water.

Dietary Considerations

Some products may contain potassium and/or sodium.

Storage

Store at 15°C to 30°C (59°F to 86°F).

Oral solution: Discard remaining medication within 24 hours of opening.

Drug Interactions

Alfacalcidol: May increase the serum concentration of Magnesium Salts. Management: Consider using a non-magnesium-containing antacid or phosphate-binding product in patients also receiving alfacalcidol. If magnesium-containing products must be used with alfacalcidol, serum magnesium concentrations should be monitored closely. Consider therapy modification

Alpha-Lipoic Acid: Magnesium Salts may decrease the absorption of Alpha-Lipoic Acid. Alpha-Lipoic Acid may decrease the absorption of Magnesium Salts. Management: Separate administration of alpha-lipoic acid from that of any magnesium-containing compounds by several hours. If alpha-lipoic acid is given 30 minutes before breakfast, then administer oral magnesium-containing products at lunch or dinner. Consider therapy modification

Aluminum Hydroxide: Citric Acid Derivatives may increase the absorption of Aluminum Hydroxide. Monitor therapy

Baloxavir Marboxil: Polyvalent Cation Containing Products may decrease the serum concentration of Baloxavir Marboxil. Avoid combination

Bictegravir: Polyvalent Cation Containing Products may decrease the serum concentration of Bictegravir. Management: Administer bictegravir under fasting conditions at least 2 hours before or 6 hours after polyvalent cation containing products. Coadministration of bictegravir with or 2 hours after most polyvalent cation products is not recommended. Consider therapy modification

Bisphosphonate Derivatives: Polyvalent Cation Containing Products may decrease the serum concentration of Bisphosphonate Derivatives. Management: Avoid administration of oral medications containing polyvalent cations within: 2 hours before or after tiludronate/clodronate/etidronate; 60 minutes after oral ibandronate; or 30 minutes after alendronate/risedronate. Consider therapy modification

Calcitriol (Systemic): May increase the serum concentration of Magnesium Salts. Management: Consider using a non-magnesium-containing antacid or phosphate-binding product in patients also receiving calcitriol. If magnesium-containing products must be used with calcitriol, serum magnesium concentrations should be monitored closely. Consider therapy modification

Calcium Channel Blockers: May enhance the adverse/toxic effect of Magnesium Salts. Magnesium Salts may enhance the hypotensive effect of Calcium Channel Blockers. Monitor therapy

Calcium Polystyrene Sulfonate: Laxatives (Magnesium Containing) may enhance the adverse/toxic effect of Calcium Polystyrene Sulfonate. More specifically, concomitant use of calcium polystyrene sulfonate with magnesium-containing laxatives may result in metabolic alkalosis or with sorbitol may result in intestinal necrosis. Management: Avoid concomitant use of calcium polystyrene sulfonate (rectal or oral) and magnesium-containing laxatives. Avoid combination

Deferiprone: Polyvalent Cation Containing Products may decrease the serum concentration of Deferiprone. Management: Separate administration of deferiprone and oral medications or supplements that contain polyvalent cations by at least 4 hours. Consider therapy modification

Dolutegravir: Magnesium Salts may decrease the serum concentration of Dolutegravir. Management: Administer dolutegravir at least 2 hours before or 6 hours after oral magnesium salts. Administer the dolutegravir/rilpivirine combination product at least 4 hours before or 6 hours after oral magnesium salts. Consider therapy modification

Doxercalciferol: May enhance the hypermagnesemic effect of Magnesium Salts. Management: Consider using a non-magnesium-containing antacid or phosphate-binding product in patients also receiving doxercalciferol. If magnesium-containing products must be used with doxercalciferol, serum magnesium concentrations should be monitored closely. Consider therapy modification

Eltrombopag: Polyvalent Cation Containing Products may decrease the serum concentration of Eltrombopag. Management: Administer eltrombopag at least 2 hours before or 4 hours after oral administration of any polyvalent cation containing product. Consider therapy modification

Elvitegravir: Polyvalent Cation Containing Products may decrease the serum concentration of Elvitegravir. Management: Administer elvitegravir 2 hours before or 6 hours after the administration of polyvalent cation containing products. Consider therapy modification

Gabapentin: Magnesium Salts may enhance the CNS depressant effect of Gabapentin. Specifically, high dose intravenous/epidural magnesium sulfate may enhance the CNS depressant effects of gabapentin. Magnesium Salts may decrease the serum concentration of Gabapentin. Management: Administer gabapentin at least 2 hours after use of a magnesium-containing antacid. Monitor patients closely for evidence of reduced response to gabapentin therapy. Monitor for CNS depression if high dose IV/epidural magnesium sulfate is used. Consider therapy modification

Levothyroxine: Magnesium Salts may decrease the serum concentration of Levothyroxine. Management: Separate administration of oral levothyroxine and oral magnesium salts by at least 4 hours. Consider therapy modification

Multivitamins/Fluoride (with ADE): Magnesium Salts may decrease the serum concentration of Multivitamins/Fluoride (with ADE). Specifically, magnesium salts may decrease fluoride absorption. Management: To avoid this potential interaction separate the administration of magnesium salts from administration of a fluoride-containing product by at least 1 hour. Consider therapy modification

Neuromuscular-Blocking Agents: Magnesium Salts may enhance the neuromuscular-blocking effect of Neuromuscular-Blocking Agents. Monitor therapy

PenicillAMINE: Polyvalent Cation Containing Products may decrease the serum concentration of PenicillAMINE. Management: Separate the administration of penicillamine and oral polyvalent cation containing products by at least 1 hour. Consider therapy modification

Phosphate Supplements: Magnesium Salts may decrease the serum concentration of Phosphate Supplements. Management: Administer oral phosphate supplements as far apart from the administration of an oral magnesium salt as possible to minimize the significance of this interaction. Consider therapy modification

Quinolones: Magnesium Salts may decrease the serum concentration of Quinolones. Management: Administer oral quinolones several hours before (4 h for moxi/pe/spar/enox-, 2 h for others) or after (8 h for moxi-, 6 h for cipro/dela-, 4 h for lome/pe/enox-, 3 h for gemi-, and 2 h for levo-, nor-, or ofloxacin or nalidixic acid) oral magnesium salts. Consider therapy modification

Raltegravir: Magnesium Salts may decrease the serum concentration of Raltegravir. Management: Avoid the use of oral / enteral magnesium salts with raltegravir. No dose separation schedule has been established that adequately reduces the magnitude of interaction. Avoid combination

Sodium Polystyrene Sulfonate: Laxatives (Magnesium Containing) may enhance the adverse/toxic effect of Sodium Polystyrene Sulfonate. More specifically, concomitant use of sodium polystyrene sulfonate with magnesium-containing laxatives may result in metabolic alkalosis or with sorbitol may result in intestinal necrosis. Management: Avoid concomitant use of sodium polystyrene sulfonate (rectal or oral) and magnesium-containing laxatives. Avoid combination

Tetracyclines: Magnesium Salts may decrease the absorption of Tetracyclines. Only applicable to oral preparations of each agent. Management: Avoid coadministration of oral magnesium salts and oral tetracyclines. If coadministration cannot be avoided, administer oral magnesium at least 2 hours before, or 4 hours after, oral tetracyclines. Monitor for decreased tetracycline therapeutic effects. Consider therapy modification

Trientine: Polyvalent Cation Containing Products may decrease the serum concentration of Trientine. Management: Avoid concomitant administration of trientine and oral products that contain polyvalent cations. If oral iron supplements are required, separate the administration by 2 hours. If other oral polyvalent cations are needed, separate administration by 1 hour. Consider therapy modification

Test Interactions

Increased magnesium; decreased protein, decreased calcium (S), decreased potassium (S)

Adverse Reactions

The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.

Frequency not defined: Gastrointestinal: Abdominal pain, diarrhea, flatulence, nausea, vomiting

Warnings/Precautions

Disease-related concerns:

• Constipation (self-medication, OTC use): Appropriate use: For occasional use only; serious side effects may occur with prolonged use. For use only under the supervision of a physician in patients with kidney dysfunction, sodium- or magnesium-restricted diets, abdominal pain/nausea/vomiting, with a sudden change in bowel habits which has persisted for >2 weeks, or use of a laxative for >1 week. If rectal bleeding develops or a bowel movement does not occur after use, discontinue use and consult a health care provider.

• Neuromuscular disease: Use with extreme caution in patients with myasthenia gravis or other neuromuscular disease.

• Renal impairment: Use with caution in patients with renal impairment; accumulation of magnesium may lead to magnesium intoxication.

Pregnancy Considerations

Magnesium crosses the placenta; serum concentrations in the fetus are similar to those in the mother (Idama 1998; Osada 2002).

When dietary changes and lifestyle modifications are insufficient, agents other than magnesium citrate are recommended for the treatment of constipation in pregnant women (Gomes 2018; Shin 2015).

Patient Education

What is this drug used for?

• It is used to clean out the GI (gastrointestinal) tract.

• It is used to treat constipation.

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Abdominal pain

• Diarrhea

• Passing gas

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a limited summary of general information about the medicine's uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.

Frequently asked questions

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.