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Magnesium Carbonate

Generic name: magnesium carbonate systemic

Brand names: Mag-Carb, Dewees Carminative, Magonate

Dosage Forms

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

Liquid, Oral:

Magonate: Elemental magnesium 54 mg/5 mL (355 mL) [contains sodium benzoate; mixed melon flavor]

Powder, Oral:

Generic: Elemental magnesium 250 mg/g (480 g)

Pharmacology

Mechanism of Action

Magnesium is important as a cofactor in many enzymatic reactions in the body involving protein synthesis and carbohydrate metabolism (at least 300 enzymatic reactions require magnesium). Actions on lipoprotein lipase have been found to be important in reducing serum cholesterol and on sodium/potassium ATPase in promoting polarization (eg, neuromuscular functioning).

Pharmacokinetics/Pharmacodynamics

Absorption

Oral: Primary site of absorption of the magnesium cation is in the distal small intestine; some insignificant absorption occurs in the colon (Ranade 2001)

Excretion

Urine (almost exclusively) (Ranade 2001)

Protein Binding

~ 33% bound to albumin (Ranade 2001)

Use: Labeled Indications

Dietary supplement

Dosage and Administration

Dosing: Adult

Dietary supplement: Oral (Magonate liquid): 5 mL (54 mg of elemental magnesium) up to 3 times daily.

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Note: 5 mL of Magonate (magnesium carbonate) suspension = 54 mg elemental magnesium = 4.44 mEq elemental magnesium.

Hypomagnesemia: Limited data available: Infants, Children, and Adolescents: Dose expressed as elemental magnesium: Oral: 10 to 20 mg/kg/dose up to 4 times daily; usual adult dose: 300 mg 4 times daily (Kliegman 2007). Note: Achieving optimal magnesium levels using oral therapy may be difficult due to the propensity for magnesium to cause diarrhea; IV replacement may be more appropriate particularly in situations of severe deficit.

Administration

Administer orally.

Dietary Considerations

Whole grains, legumes, and dark-green leafy vegetables are dietary sources of magnesium (IOM 1997).

Adequate intake (AI) (elemental magnesium) (IOM 1997):

1 to 6 months: 30 mg/day

7 to 12 months: 75 mg/day

Dietary recommended daily allowance (RDA) (elemental magnesium) (IOM 1997):

1 to 3 years: 80 mg/day

4 to 8 years: 130 mg/day

9 to 13 years: 240 mg/day

14 to 18 years:

Females: 360 mg/day

Pregnancy: 400 mg/day

Lactation: 360 mg/day

Males: 410 mg/day

19 to 30 years:

Females: 310 mg/day

Pregnancy: 350 mg/day

Lactation: 310 mg/day

Males: 400 mg/day

Adults ≥31 years:

Females: 320 mg/day

Pregnancy: 360 mg/day

Lactation: 320 mg/day

Males: 420 mg/day

Storage

Store at room temperature.

Drug Interactions

Acalabrutinib: Antacids may decrease the serum concentration of Acalabrutinib. Management: Separate administration of acalabrutinib from the administration of any antacids by at least 2 hours in order to minimize the potential for a significant interaction. Consider therapy modification

Alfacalcidol: May increase the serum concentration of Magnesium Salts. Consider therapy modification

Allopurinol: Antacids may decrease the absorption of Allopurinol. 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. Consider therapy modification

Amphetamines: Antacids may decrease the excretion of Amphetamines. Monitor therapy

Antipsychotic Agents (Phenothiazines): Antacids may decrease the absorption of Antipsychotic Agents (Phenothiazines). Monitor therapy

Atazanavir: Antacids may decrease the absorption of Atazanavir. Consider therapy modification

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

Bisacodyl: Antacids may diminish the therapeutic effect of Bisacodyl. Antacids may cause the delayed-release bisacodyl tablets to release drug prior to reaching the large intestine. Gastric irritation and/or cramps may occur. Consider therapy modification

Bismuth Subcitrate: Antacids may diminish the therapeutic effect of Bismuth Subcitrate. Management: Avoid administration of antacids within 30 minutes of bismuth subcitrate (tripotassium bismuth dicitrate) administration. 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. Exceptions: Pamidronate; Zoledronic Acid. Consider therapy modification

Bosutinib: Antacids may decrease the serum concentration of Bosutinib. Management: Administer antacids more than 2 hours before or after bosutinib. Consider therapy modification

Bromperidol: Antacids may decrease the absorption of Bromperidol. Monitor therapy

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: Antacids may enhance the adverse/toxic effect of Calcium Polystyrene Sulfonate. The combined use of these two agents may result in metabolic alkalosis and/or loss of efficacy of the cation exchange resin. Management: To minimize this interaction, consider: a)separating doses by 2 or more hours; b)rectal administration of the exchange resin; or c)alternatives to antacids. Monitor for metabolic alkalosis and attenuation of CPS effects. Avoid magnesium hydroxide. Consider therapy modification

Captopril: Antacids may decrease the serum concentration of Captopril. Monitor therapy

Cefditoren: Antacids may decrease the serum concentration of Cefditoren. Management: Concomitant use of cefditoren with antacids is not recommended. Consider alternative methods to control acid reflux (eg, diet modification) or alternative antimicrobial therapy. If antacid therapy can not be avoided, separate dosing by several hours. Consider therapy modification

Cefpodoxime: Antacids may decrease the serum concentration of Cefpodoxime. Monitor therapy

Cefuroxime: Antacids may decrease the serum concentration of Cefuroxime. Management: Administer cefuroxime axetil at least 1 hour before or 2 hours after the administration of short-acting antacids. Consider therapy modification

Chloroquine: Antacids may decrease the serum concentration of Chloroquine. Management: Separate administration of antacids and chloroquine by at least 4 hours to minimize any potential negative impact of antacids on chloroquine bioavailability. Consider therapy modification

Corticosteroids (Oral): Antacids may decrease the bioavailability of Corticosteroids (Oral). Management: Consider separating doses by 2 or more hours. Budesonide enteric coated tablets could dissolve prematurely if given with drugs that lower gastric acid, with unknown impact on budesonide therapeutic effects. Consider therapy modification

Cysteamine (Systemic): Antacids may diminish the therapeutic effect of Cysteamine (Systemic). Monitor therapy

Dabigatran Etexilate: Antacids may decrease the serum concentration of Dabigatran Etexilate. Management: Dabigatran etexilate Canadian product labeling recommends avoiding concomitant use with antacids for 24 hours after surgery. In other situations, administer dabigatran etexilate 2 hours prior to antacids. Monitor clinical response to dabigatran therapy. Consider therapy modification

Dasatinib: Antacids may decrease the serum concentration of Dasatinib. Management: Simultaneous administration of dasatinib and antacids should be avoided. Administer antacids 2 hours before or 2 hours after dasatinib. Consider therapy modification

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

Delavirdine: Antacids may decrease the serum concentration of Delavirdine. Management: Separate doses of delavirdine and antacids by at least 1 hour. Monitor for decreased delavirdine therapeutic effects with this combination. Consider therapy modification

Dexmethylphenidate: Antacids may increase the absorption of Dexmethylphenidate. Specifically, antacids may interfere with the normal release of drug from the extended-release capsules (Focalin XR brand), which could result in both increased absorption (early) and decreased delayed absorption. Monitor therapy

Diacerein: Antacids may decrease the absorption of Diacerein. Monitor therapy

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: Antacids may decrease the serum concentration of Elvitegravir. Management: Separate administration of antacids and elvitegravir-containing products by at least 2 hours in order to minimize the risk for an interaction. Consider therapy modification

Erdafitinib: Serum Phosphate Level-Altering Agents may diminish the therapeutic effect of Erdafitinib. Management: Avoid coadministration of serum phosphate level-altering agents with erdafitinib before initial dose increase period based on serum phosphate levels (Days 14 to 21). Consider therapy modification

Erlotinib: Antacids may decrease the serum concentration of Erlotinib. Management: Separate the administration of erlotinib and any antacid by several hours in order to minimize the risk of a significant interaction. Consider therapy modification

Fexofenadine: Antacids may decrease the serum concentration of Fexofenadine. Management: Separate the administration of fexofenadine and aluminum- or magnesium-containing antacids. Consider therapy modification

Fosinopril: Antacids may decrease the serum concentration of Fosinopril. Management: The US and Canadian fosinopril manufacturer labels recommend separating the doses of antacids and fosinopril by 2 hours. 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

Gefitinib: Antacids may decrease the serum concentration of Gefitinib. Management: Administer gefitinib at least 6 hours before or after administration of an antacid, and closely monitor clinical response to gefitinib. Consider therapy modification

Hyoscyamine: Antacids may decrease the serum concentration of Hyoscyamine. Management: Administer immediate release hyoscyamine before meals and antacids after meals when these agents are given in combination. Consider therapy modification

Iron Preparations: Antacids may decrease the absorption of Iron Preparations. Management: Separate dosing of oral iron preparations and antacids as much as possible to avoid decreased efficacy of iron preparation. If coadministered with antacids, monitor for decreased therapeutic effects of iron preparations. Exceptions: Ferric Carboxymaltose; Ferric Citrate; Ferric Derisomaltose; Ferric Gluconate; Ferric Hydroxide Polymaltose Complex; Ferric Pyrophosphate Citrate; Ferumoxytol; Iron Dextran Complex; Iron Sucrose. Consider therapy modification

Itraconazole: Antacids may decrease the serum concentration of Itraconazole. Antacids may increase the serum concentration of Itraconazole. Management: Administer Sporanox brand itraconazole at least 2 hours before or 2 hours after administration of any antacids. Exposure to Tolsura brand itraconazole may be increased by antacids; consider itraconazole dose reduction. Consider therapy modification

Ketoconazole (Systemic): Antacids may decrease the serum concentration of Ketoconazole (Systemic). Management: Administer oral ketoconazole at least 2 hours prior to use of any antacid product. Monitor patients closely for signs of inadequate clinical response to ketoconazole. Consider therapy modification

Lanthanum: Antacids may diminish the therapeutic effect of Lanthanum. Consider therapy modification

Ledipasvir: Antacids may decrease the serum concentration of Ledipasvir. Management: Separate the administration of ledipasvir and antacids by 4 hours. 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

Mesalamine: Antacids may diminish the therapeutic effect of Mesalamine. Antacid-mediated increases in gastrointestinal pH may cause the premature release of mesalamine from specific sustained-release mesalamine products. Management: Avoid concurrent administration of antacids with sustained-release mesalamine products. Separating antacid and mesalamine administration, and/or using lower antacid doses may be adequate means of avoiding this interaction. Consider therapy modification

Methenamine: Antacids may diminish the therapeutic effect of Methenamine. Consider therapy modification

Methylphenidate: Antacids may increase the absorption of Methylphenidate. Specifically, antacids may interfere with the normal release of drug from the extended-release capsules (Ritalin LA brand), which could result in both increased absorption (early) and decreased delayed absorption. Monitor therapy

MiSOPROStol: Antacids may enhance the adverse/toxic effect of MiSOPROStol. More specifically, concomitant use with magnesium-containing antacids may increase the risk of diarrhea. Management: Avoid concomitant use of misoprostol and magnesium-containing antacids. In patients requiring antacid therapy, employ magnesium-free preparations. Monitor for increased adverse effects (e.g., diarrhea, dehydration). Avoid combination

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

Multivitamins/Minerals (with ADEK, Folate, Iron): Antacids may decrease the serum concentration of Multivitamins/Minerals (with ADEK, Folate, Iron). Specifically, antacids may decrease the absorption of orally administered iron. Management: Separate dosing of oral iron-containing multivitamin preparations and antacids by as much time as possible in order to minimize impact on therapeutic efficacy of the iron preparation. Consider therapy modification

Mycophenolate: Antacids may decrease the absorption of Mycophenolate. Management: Separate doses of mycophenolate and antacids by at least 2 hours. Monitor for reduced effects of mycophenolate if taken concomitant with antacids. Consider therapy modification

Mycophenolate: Magnesium Salts may decrease the serum concentration of Mycophenolate. Management: Separate doses of mycophenolate and oral magnesium salts. Monitor for reduced effects of mycophenolate if taken concomitant with oral magnesium salts. Consider therapy modification

Neratinib: Antacids may decrease the serum concentration of Neratinib. Specifically, antacids may reduce neratinib absorption. Management: Separate the administration of neratinib and antacids by giving neratinib at least 3 hours after the antacid. Consider therapy modification

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

Nilotinib: Antacids may decrease the serum concentration of Nilotinib. Management: Separate the administration of nilotinib and any antacid by at least 2 hours whenever possible in order to minimize the risk of a significant interaction. Consider therapy modification

PAZOPanib: Antacids may decrease the serum concentration of PAZOPanib. Management: Avoid the use of antacids in combination with pazopanib whenever possible. Separate doses by several hours if antacid treatment is considered necessary. The impact of dose separation has not been investigated. Consider therapy modification

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

Pexidartinib: Antacids may decrease the serum concentration of Pexidartinib. Management: Administer pexidartinib 2 hours before or after antacids. Consider therapy modification

Phosphate Supplements: Antacids may decrease the absorption of Phosphate Supplements. Management: This applies only to oral phosphate administration. Separating administer of oral phosphate supplements from antacid administration by as long as possible may minimize the interaction. Exceptions: Sodium Glycerophosphate Pentahydrate. 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. Exceptions: Sodium Glycerophosphate Pentahydrate. Consider therapy modification

Potassium Phosphate: Antacids may decrease the serum concentration of Potassium Phosphate. Management: Consider separating administration of antacids and oral potassium phosphate by at least 2 hours to decrease risk of a significant interaction. Consider therapy modification

QuiNIDine: Antacids may decrease the excretion of QuiNIDine. Monitor therapy

QuiNINE: Antacids may decrease the serum concentration of QuiNINE. Avoid combination

Quinolones: Antacids may decrease the absorption of Quinolones. Of concern only with oral administration of quinolones. Management: Avoid concurrent administration of quinolones and antacids to minimize the impact of this interaction. Recommendations for optimal dose separation vary by specific quinolone. Exceptions: LevoFLOXacin (Oral Inhalation). 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-, 2 h for others) or after (8 h for moxi-, 6 h for cipro/dela-, 4 h for lome/pe-, 3 h for gemi-, and 2 h for levo-, nor-, or ofloxacin or nalidixic acid) oral magnesium salts. Exceptions: LevoFLOXacin (Oral Inhalation). 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

Rilpivirine: Antacids may decrease the serum concentration of Rilpivirine. Management: Administer antacids at least 2 hours before or 4 hours after rilpivirine. Administer antacids at least 6 hours before or 4 hours after the rilpivirine/dolutegravir combination product. Consider therapy modification

Riociguat: Antacids may decrease the serum concentration of Riociguat. Management: Separate the administration of antacids and riociguat by at least 1 hour in order to minimize any potential interaction. Consider therapy modification

Rosuvastatin: Antacids may decrease the serum concentration of Rosuvastatin. Monitor therapy

Sodium Polystyrene Sulfonate: Antacids may enhance the adverse/toxic effect of Sodium Polystyrene Sulfonate. The combined use of these two agents may result in metabolic alkalosis and/or loss of efficacy of the exchange resin. Management: To minimize this interaction, consider: a)separating doses by 2 or more hours; b)rectal administration of the exchange resin; or c)alternatives to antacids. Monitor for metabolic alkalosis and attenuation of SPS effects. Avoid magnesium hydroxide. Consider therapy modification

Sotalol: Antacids may decrease the serum concentration of Sotalol. Management: Avoid simultaneous administration of sotalol and antacids. Administer antacids 2 hours after sotalol. Consider therapy modification

Sulpiride: Antacids may decrease the serum concentration of Sulpiride. Management: Separate administration of antacids and sulpiride by at least 2 hours in order to minimize the impact of antacids on sulpiride absorption. Consider therapy modification

Tetracyclines: Antacids may decrease the absorption of Tetracyclines. Management: Separate administration of antacids and oral tetracycline derivatives by several hours when possible to minimize the extent of this potential interaction. Exceptions: Eravacycline. Consider therapy modification

Tetracyclines: Magnesium Salts may decrease the absorption of Tetracyclines. Only applicable to oral preparations of each agent. Exceptions: Eravacycline. 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

Velpatasvir: Antacids may decrease the serum concentration of Velpatasvir. Management: Separate administration of velpatasvir and antacids by at least 4 hours. Consider therapy modification

Adverse Reactions

No adverse reactions listed in the manufacturer's labeling.

Warnings/Precautions

Concerns related to adverse effects:

  • GI effects: Diarrhea may occur with high doses of magnesium.

Disease-related concerns:

  • 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.

Dosage form specific issues:

  • Benzyl alcohol and derivatives: Some dosage forms may contain sodium benzoate/benzoic acid; benzoic acid (benzoate) is a metabolite of benzyl alcohol; large amounts of benzyl alcohol (≥99 mg/kg/day) have been associated with a potentially fatal toxicity (“gasping syndrome”) in neonates; the “gasping syndrome” consists of metabolic acidosis, respiratory distress, gasping respirations, CNS dysfunction (including convulsions, intracranial hemorrhage), hypotension, and cardiovascular collapse (AAP ["Inactive" 1997]; CDC 1982); some data suggests that benzoate displaces bilirubin from protein binding sites (Ahlfors 2001); avoid or use dosage forms containing benzyl alcohol derivative with caution in neonates. See manufacturer's labeling.

Pregnancy

Pregnancy Considerations

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

Patient Education

What is this drug used for?

  • It is used to treat or prevent low magnesium levels.

Other side effects of this drug: Talk with your doctor right away if you have any of these signs of:

  • Severe diarrhea
  • Signs of a significant reaction like wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of 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 brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.

Source: Wolters Kluwer Health. Last updated January 30, 2020.