calcium carbonate/magnesium hydroxide (OTC)

Brand and Other Names:Rolaids Extra Strength, Rolaids Regular Strength, more...Rolaids Regular Strength Liquid, Rolaids Ultra Strength, Rolaids Ultra Strength Liquid, Mylanta Supreme
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Dosing & Uses

AdultPediatric

Dosing Forms & Strengths

calcium carbonate/magnesium hydroxide

chewable tablet

  • 550mg/110mg (Rolaids Regular Strength)
  • 675mg/135mg (Rolaids Extra Strength)
  • 1000mg/200mg (Rolaids Ultra Strength)

oral suspension

  • (400mg/135mg)/5mL (Mylanta Supreme)
  • (550mg/110mg)/5mL (Rolaids Regular Strength Liquid)
  • (1000mg/200mg)/5mL (Rolaids Ultra Strength Liquid)

Heartburn & Indigestion

Antacid: Typical dose 800-3,000 mg of calcium carbonate PO prn for symptoms

Tablet: Chew 2-4 tabs PO prn

Suspension: 10-20 mL PO prn

Tablet and suspension strength varies; not to exceed ~7 g of calcium carbonate/day

Dosing Considerations

Calcium carbonate (elemental calcium equivalent)

  • 400 mg (160 mg)
  • 550 mg (220 mg)
  • 675 mg (270 mg)
  • 1000 mg (400 mg)

Magnesium hydroxide (elemental magnesium equivalent)

  • 110 mg (45 mg)
  • 135 mg (55 mg)
  • 200 mg (85 mg)

Administration

Avoid taking drugs whose absorption is affected by antacids within 1 hr of administration

Suspension: Shake well before using, protect from freezing

Tablets: Chew thoroughly

Safety and efficacy not established

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Interactions

Interaction Checker

and calcium carbonate/magnesium hydroxide

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            Contraindicated (1)

            • ceftriaxone

              ceftriaxone, calcium carbonate. Other (see comment). Contraindicated. Comment: Do not use ANY calcium containing solutions (including Ringer or Harmann solutions) in combination with IV ceftriaxone; risk of potentially fatal particulate precipitation in lungs, kidneys. Separate by at least 48 hrs.

            Serious - Use Alternative (27)

            • atazanavir

              calcium carbonate will decrease the level or effect of atazanavir by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Atazanavir solubility decreases as pH increases. Reduced plasma concentrations of atazanavir are expected if antacids or buffered medications are coadministered. Administer atazanavir 2 hr before or 1 hr after these medications.

            • baloxavir marboxil

              magnesium hydroxide will decrease the level or effect of baloxavir marboxil by cation binding in GI tract. Avoid or Use Alternate Drug. Baloxavir may bind to polyvalent cations resulting in decreased absorption. Studies in monkeys showed concurrent use with calcium, aluminum, or iron caused significantly decreased plasma levels. Human studies not conducted.

              calcium carbonate will decrease the level or effect of baloxavir marboxil by cation binding in GI tract. Avoid or Use Alternate Drug. Baloxavir may bind to polyvalent cations resulting in decreased absorption. Studies in monkeys showed concurrent use with calcium, aluminum, or iron caused significantly decreased plasma levels. Human studies not conducted.

            • dapsone

              calcium carbonate will decrease the level or effect of dapsone by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

            • demeclocycline

              magnesium hydroxide decreases levels of demeclocycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

            • dasatinib

              calcium carbonate will decrease the level or effect of dasatinib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

            • demeclocycline

              calcium carbonate, demeclocycline. Either decreases levels of the other by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

            • digoxin

              calcium carbonate will increase the level or effect of digoxin by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

            • doxycycline

              magnesium hydroxide decreases levels of doxycycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

              calcium carbonate, doxycycline. Either decreases levels of the other by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

            • eltrombopag

              calcium carbonate decreases levels of eltrombopag by inhibition of GI absorption. Applies only to oral form of both agents. Contraindicated. Separate by at least 4 hours.

              magnesium hydroxide decreases levels of eltrombopag by inhibition of GI absorption. Applies only to oral form of both agents. Contraindicated. Separate by at least 4 hours.

            • erdafitinib

              calcium carbonate, erdafitinib. Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid coadministration during initial dosing adjustment period (ie, first 21 days). Increases in serum phosphate levels are a pharmacodynamic effect of FGFR inhibition. Serum phosphate binders may obscure decisions regarding initial dosage increase.

            • infigratinib

              magnesium hydroxide will decrease the level or effect of infigratinib by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. If use with an acid-reducing agent cannot be avoided, administer infigratinib 2 hr before and after administration of a locally-acting antacid.

            • indinavir

              calcium carbonate will decrease the level or effect of indinavir by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

            • infigratinib

              calcium carbonate will decrease the level or effect of infigratinib by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. If use with an acid-reducing agent cannot be avoided, administer infigratinib 2 hr before and after administration of a locally-acting antacid.

            • ketoconazole

              calcium carbonate will decrease the level or effect of ketoconazole by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

            • minocycline

              magnesium hydroxide decreases levels of minocycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

              calcium carbonate, minocycline. Either decreases levels of the other by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

            • nimodipine

              calcium carbonate will increase the level or effect of nimodipine by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

            • oxytetracycline

              magnesium hydroxide decreases levels of oxytetracycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

            • nisoldipine

              calcium carbonate will increase the level or effect of nisoldipine by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

            • nitrendipine

              calcium carbonate will increase the level or effect of nitrendipine by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

            • oxytetracycline

              calcium carbonate, oxytetracycline. Either decreases levels of the other by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

            • pazopanib

              calcium carbonate will decrease the level or effect of pazopanib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Avoid coadministration of pazopanib with drugs that raise gastric pH; may use short-acting antacids in place of PPIs and H2 antagonists, but separate antacid and pazopanib dosing by several hours

              magnesium hydroxide will decrease the level or effect of pazopanib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Avoid coadministration of pazopanib with drugs that raise gastric pH; may use short-acting antacids in place of PPIs and H2 antagonists, but separate antacid and pazopanib dosing by several hours

            • ponatinib

              magnesium hydroxide decreases levels of ponatinib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

              calcium carbonate decreases levels of ponatinib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

            • potassium phosphates, IV

              magnesium hydroxide decreases effects of potassium phosphates, IV by cation binding in GI tract. Avoid or Use Alternate Drug. Magnesium decreases serum phosphate concentration by binding dietary phosphate. Use alternatives if available.

            • sotorasib

              calcium carbonate will decrease the level or effect of sotorasib by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. If use with an acid-reducing agent cannot be avoided, administer sotorasib 4 hr before or 10 hr after administration of a locally-acting antacid.

            • raltegravir

              magnesium hydroxide will decrease the level or effect of raltegravir by cation binding in GI tract. Avoid or Use Alternate Drug. Magnesium containing antacids reduce raltegravir plasma levels when taken within 6 hr of raltegravir dose

            • sotorasib

              magnesium hydroxide will decrease the level or effect of sotorasib by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. If use with an acid-reducing agent cannot be avoided, administer sotorasib 4 hr before or 10 hr after administration of a locally-acting antacid.

            • tetracycline

              magnesium hydroxide decreases levels of tetracycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

              calcium carbonate, tetracycline. Either decreases levels of the other by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

            Monitor Closely (145)

            • acalabrutinib

              calcium carbonate decreases levels of acalabrutinib by increasing gastric pH. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Acalabrutinib solubility decreases with increasing gastric pH. Separate dosing by at least 2 hr between administration of antacids and acalabrutinib.

            • acebutolol

              calcium carbonate decreases effects of acebutolol by unspecified interaction mechanism. Use Caution/Monitor.

              calcium carbonate decreases levels of acebutolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • alendronate

              calcium carbonate decreases levels of alendronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 30 minutes.

            • allopurinol

              calcium carbonate decreases levels of allopurinol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • amantadine

              calcium carbonate will increase the level or effect of amantadine by Other (see comment). Modify Therapy/Monitor Closely. Urine pH changes towards alkalinic conditions may lead to an accumulation of amantadine with a possible increase in adverse reactions. Monitor for adverse reactions of amantadine.

            • amlodipine

              calcium carbonate decreases effects of amlodipine by pharmacodynamic antagonism. Use Caution/Monitor.

            • atenolol

              calcium carbonate decreases effects of atenolol by unspecified interaction mechanism. Use Caution/Monitor.

              calcium carbonate decreases levels of atenolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • azithromycin

              calcium carbonate decreases levels of azithromycin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • bearberry

              calcium carbonate will increase the level or effect of bearberry by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

            • benazepril

              calcium carbonate decreases effects of benazepril by unspecified interaction mechanism. Use Caution/Monitor.

            • benzphetamine

              calcium carbonate will increase the level or effect of benzphetamine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

            • betaxolol

              calcium carbonate decreases effects of betaxolol by unspecified interaction mechanism. Use Caution/Monitor.

              calcium carbonate decreases levels of betaxolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • bictegravir

              magnesium hydroxide will decrease the level or effect of bictegravir by cation binding in GI tract. Modify Therapy/Monitor Closely. Bictegravir can be taken under fasting conditions 2 hr before antacids containing Al, Mg, or Ca. Routine administration of bictegravir simultaneously with, or 2 hr after, antacids containing Al, Mg, or Ca is not recommended.

              calcium carbonate will decrease the level or effect of bictegravir by cation binding in GI tract. Modify Therapy/Monitor Closely. Bictegravir can be taken under fasting conditions 2 hr before antacids containing calcium. However, bictegravir and supplements containing calcium can be taken together with food. Routine administration of bictegravir (under fasting conditions) simultaneously with, or 2 hr after, calcium supplements or antacids containing calcium is not recommended.

            • bisoprolol

              calcium carbonate decreases effects of bisoprolol by unspecified interaction mechanism. Use Caution/Monitor.

              calcium carbonate decreases levels of bisoprolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • cabotegravir

              magnesium hydroxide will decrease the level or effect of cabotegravir by cation binding in GI tract. Modify Therapy/Monitor Closely. Administer antacid products at least 2 hr before or 4 hr after taking oral cabotegravir.

            • bosutinib

              calcium carbonate decreases levels of bosutinib by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor. Bosutinib displays pH-dependent solubility; may use short-acting antacids with administration separated by 2 hr.

            • budesonide

              calcium carbonate decreases effects of budesonide by increasing gastric pH. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Enteric-coated budesonide dissolves at pH >5.5. Also, dissolution of extended-release budesonide tablets is pH dependent. Coadministration with drugs that increase gastric pH may cause these budesonide products to prematurely dissolve, and possibly affect release properties and absorption of the drug in the duodenum.

            • cabotegravir

              calcium carbonate will decrease the level or effect of cabotegravir by cation binding in GI tract. Modify Therapy/Monitor Closely. Administer antacid products at least 2 hr before or 4 hr after taking oral cabotegravir.

            • captopril

              calcium carbonate decreases effects of captopril by unspecified interaction mechanism. Use Caution/Monitor. Calcium carbonate may decrease absorption of captopril.

            • carbonyl iron

              calcium carbonate will decrease the level or effect of carbonyl iron by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • carvedilol

              calcium carbonate decreases effects of carvedilol by unspecified interaction mechanism. Use Caution/Monitor.

              calcium carbonate decreases levels of carvedilol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • cefdinir

              calcium carbonate will decrease the level or effect of cefdinir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • cefditoren

              calcium carbonate will decrease the level or effect of cefditoren by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • cefpodoxime

              calcium carbonate will decrease the level or effect of cefpodoxime by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • cefuroxime

              calcium carbonate will decrease the level or effect of cefuroxime by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • celecoxib

              calcium carbonate decreases levels of celecoxib by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • celiprolol

              calcium carbonate decreases effects of celiprolol by unspecified interaction mechanism. Use Caution/Monitor.

              calcium carbonate decreases levels of celiprolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • chenodiol

              calcium carbonate decreases levels of chenodiol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • chloroquine

              calcium carbonate will decrease the level or effect of chloroquine by cation binding in GI tract. Use Caution/Monitor. Separate doses by at least 4 hr

              magnesium hydroxide will decrease the level or effect of chloroquine by Mechanism: inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Separate doses by at least 4 hr

            • ciprofloxacin

              magnesium hydroxide decreases levels of ciprofloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Coadministration of ciprofloxacin with multivalent cation-containing products may reduce the bioavailability of ciprofloxacin by 90%. Administer ciprofloxacin at least 2 hours before or 6 hours after using these products. Use alternatives if available.

              calcium carbonate decreases effects of ciprofloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Ciprofloxacin should be administered 2 hr before or 6 hr after calcium salts.

            • clevidipine

              calcium carbonate decreases effects of clevidipine by pharmacodynamic antagonism. Use Caution/Monitor.

            • crizotinib

              magnesium hydroxide decreases levels of crizotinib by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor. Drugs that elevate the gastric pH may decrease the solubility of crizotinib and subsequently reduce its bioavailability. However, no formal studies have been conducted. .

            • crizotinib

              calcium carbonate decreases levels of crizotinib by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor. Drugs that elevate the gastric pH may decrease the solubility of crizotinib and subsequently reduce its bioavailability. However, no formal studies have been conducted. .

            • cyclosporine

              calcium carbonate decreases levels of cyclosporine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • dabrafenib

              calcium carbonate will decrease the level or effect of dabrafenib by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor. Drugs that alter upper GI tract pH (eg, PPIs, H2-blockers, antacids) may decrease dabrafenib solubility and reduce its bioavailability

            • deferiprone

              magnesium hydroxide decreases levels of deferiprone by enhancing GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Deferiprone may bind polyvalent cations (eg, iron, aluminum, and zinc), separate administration by at least 4 hr between deferiprone and other medications (eg, antacids), or supplements containing these polyvalent cations.

              calcium carbonate decreases levels of deferiprone by enhancing GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Deferiprone may bind polyvalent cations (eg, iron, aluminum, and zinc), separate administration by at least 4 hr between deferiprone and other medications (eg, antacids), or supplements containing these polyvalent cations.

            • deferoxamine

              deferoxamine decreases levels of calcium carbonate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Deferoxamine chelates iron; its affinity for other minerals is unknown.

            • deflazacort

              magnesium hydroxide and deflazacort both decrease serum potassium. Use Caution/Monitor.

            • delafloxacin

              calcium carbonate will decrease the level or effect of delafloxacin by cation binding in GI tract. Modify Therapy/Monitor Closely. Oral delafloxacin form chelates with alkaline earth and transition metal cations. Administer oral delafloxacin at least 2 hr before or 6 hr after these agents.

            • dextroamphetamine

              calcium carbonate will increase the level or effect of dextroamphetamine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

            • digoxin

              calcium carbonate increases effects of digoxin by pharmacodynamic synergism. Use Caution/Monitor.

            • diltiazem

              calcium carbonate decreases effects of diltiazem by pharmacodynamic antagonism. Use Caution/Monitor.

            • dolutegravir

              magnesium hydroxide will decrease the level or effect of dolutegravir by cation binding in GI tract. Use Caution/Monitor. Administer dolutegravir 2 hr before or 6 hr after taking medications containing polyvalent cations; use alternative therapy if available

              calcium carbonate will decrease the level or effect of dolutegravir by cation binding in GI tract. Modify Therapy/Monitor Closely. Administer dolutegravir 2 hr (dolutegravir or abacavir/dolutegravir/lamivudine) or 4 hr (dolutegravir/rilpivirine) before or 6 hr after taking medications containing polyvalent cations.

            • elvitegravir

              calcium carbonate will decrease the level or effect of elvitegravir by cation binding in GI tract. Modify Therapy/Monitor Closely. Elvitegravir plasma concentrations are lower with antacids due to the formation of ionic complexes in the GI tract and not due to changes in gastric pH; separate dose from antacid by at least 2 hr

            • fleroxacin

              magnesium hydroxide decreases levels of fleroxacin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • elvitegravir/cobicistat/emtricitabine/tenofovir DF

              calcium carbonate decreases levels of elvitegravir/cobicistat/emtricitabine/tenofovir DF by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate administration from antacids by 2 hr.

            • enalapril

              calcium carbonate decreases effects of enalapril by unspecified interaction mechanism. Use Caution/Monitor.

            • ephedrine

              calcium carbonate will increase the level or effect of ephedrine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

            • erythromycin base

              calcium carbonate increases levels of erythromycin base by unknown mechanism. Use Caution/Monitor.

            • erythromycin ethylsuccinate

              calcium carbonate increases levels of erythromycin ethylsuccinate by unknown mechanism. Use Caution/Monitor.

            • erythromycin lactobionate

              calcium carbonate increases levels of erythromycin lactobionate by unknown mechanism. Use Caution/Monitor.

            • erythromycin stearate

              calcium carbonate increases levels of erythromycin stearate by unknown mechanism. Use Caution/Monitor.

            • esmolol

              calcium carbonate decreases effects of esmolol by unspecified interaction mechanism. Use Caution/Monitor.

              calcium carbonate decreases levels of esmolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • estramustine

              calcium carbonate decreases levels of estramustine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Patients should take estramustine with water at least 1h before or 2h after meals.

            • etidronate

              calcium carbonate decreases levels of etidronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 30 minutes.

            • felodipine

              calcium carbonate decreases effects of felodipine by pharmacodynamic antagonism. Use Caution/Monitor.

            • ferric maltol

              calcium carbonate will decrease the level or effect of ferric maltol by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • ferrous fumarate

              calcium carbonate will decrease the level or effect of ferrous fumarate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • ferrous gluconate

              calcium carbonate will decrease the level or effect of ferrous gluconate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • flecainide

              calcium carbonate will increase the level or effect of flecainide by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

            • fosamprenavir

              calcium carbonate will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • fosinopril

              calcium carbonate decreases effects of fosinopril by unspecified interaction mechanism. Use Caution/Monitor.

            • gabapentin

              calcium carbonate decreases levels of gabapentin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • gabapentin enacarbil

              calcium carbonate decreases levels of gabapentin enacarbil by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • gefitinib

              calcium carbonate decreases levels of gefitinib by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor. Separate gefitinib and antacid doses by at least 6 hr.

            • gemifloxacin

              magnesium hydroxide decreases levels of gemifloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

              calcium carbonate, gemifloxacin. Either decreases levels of the other by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • glipizide

              calcium carbonate will increase the level or effect of glipizide by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • lanthanum carbonate

              lanthanum carbonate, magnesium hydroxide. cation binding in GI tract. Use Caution/Monitor. Administer antacid at least 2 hours before or after lanthanum. .

            • glyburide

              calcium carbonate will increase the level or effect of glyburide by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • ibandronate

              calcium carbonate decreases levels of ibandronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 30 minutes.

            • imidapril

              calcium carbonate decreases effects of imidapril by unspecified interaction mechanism. Use Caution/Monitor.

            • iron dextran complex

              calcium carbonate will decrease the level or effect of iron dextran complex by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • iron sucrose

              calcium carbonate will decrease the level or effect of iron sucrose by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • isoniazid

              calcium carbonate decreases levels of isoniazid by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • isradipine

              calcium carbonate decreases effects of isradipine by pharmacodynamic antagonism. Use Caution/Monitor.

            • itraconazole

              calcium carbonate will decrease the level or effect of itraconazole by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Administer acid neutralizing medicines at least 2 hours before or 2 hours after itraconazole.

            • ketoconazole

              calcium carbonate decreases levels of ketoconazole by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • labetalol

              calcium carbonate decreases effects of labetalol by unspecified interaction mechanism. Use Caution/Monitor.

              calcium carbonate decreases levels of labetalol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • lactulose

              calcium carbonate decreases effects of lactulose by pharmacodynamic antagonism. Use Caution/Monitor.

            • lanthanum carbonate

              lanthanum carbonate, calcium carbonate. cation binding in GI tract. Use Caution/Monitor. Administer antacid at least 2 hours before or after lanthanum. .

            • ledipasvir/sofosbuvir

              calcium carbonate decreases levels of ledipasvir/sofosbuvir by Other (see comment). Use Caution/Monitor. Comment: Ledipasvir solubility decreases as pH increases; drugs that increase gastric pH are expected to decrease levels of ledipasvir; separate antacid and ledipasivr/sofosbuvir administration by 4 hr.

            • levofloxacin

              magnesium hydroxide decreases levels of levofloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

              calcium carbonate, levofloxacin. Either decreases levels of the other by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • levothyroxine

              calcium carbonate decreases levels of levothyroxine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • moxifloxacin

              magnesium hydroxide decreases levels of moxifloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • lisdexamfetamine

              calcium carbonate will increase the level or effect of lisdexamfetamine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

            • lisinopril

              calcium carbonate decreases effects of lisinopril by unspecified interaction mechanism. Use Caution/Monitor.

            • memantine

              calcium carbonate will increase the level or effect of memantine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

            • methscopolamine

              calcium carbonate decreases levels of methscopolamine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

            • methylphenidate

              calcium carbonate decreases effects of methylphenidate by enhancing GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Since the characteristics of methylphenidate extended release capsules (Ritalin LA) are pH dependent, coadministration of antacids or acid suppressants could alter the release of methylphenidate. Consider separating the administration of the antacid and the methylphenidate extended-release capsules may be avoided.

            • metoprolol

              calcium carbonate decreases effects of metoprolol by unspecified interaction mechanism. Use Caution/Monitor.

              calcium carbonate decreases levels of metoprolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • mexiletine

              calcium carbonate will increase the level or effect of mexiletine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

            • moexipril

              calcium carbonate decreases effects of moexipril by unspecified interaction mechanism. Use Caution/Monitor.

            • moxifloxacin

              calcium carbonate, moxifloxacin. Either decreases levels of the other by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • mycophenolate

              calcium carbonate will decrease the level or effect of mycophenolate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • nadolol

              calcium carbonate decreases effects of nadolol by unspecified interaction mechanism. Use Caution/Monitor.

              calcium carbonate decreases levels of nadolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • nebivolol

              calcium carbonate decreases effects of nebivolol by unspecified interaction mechanism. Use Caution/Monitor.

              calcium carbonate decreases levels of nebivolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • neratinib

              calcium carbonate will decrease the level or effect of neratinib by increasing gastric pH. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Separate antacid and neratinib dosing by 3 hr.

            • nicardipine

              calcium carbonate decreases effects of nicardipine by pharmacodynamic antagonism. Use Caution/Monitor.

            • nifedipine

              calcium carbonate decreases effects of nifedipine by pharmacodynamic antagonism. Use Caution/Monitor.

            • nilotinib

              calcium carbonate decreases levels of nilotinib by increasing gastric pH. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Avoid this interaction by administering antacids 2 hr after or 2 hr before nilotinib.

            • nisoldipine

              calcium carbonate decreases effects of nisoldipine by pharmacodynamic antagonism. Use Caution/Monitor.

            • nitrofurantoin

              calcium carbonate decreases levels of nitrofurantoin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • ofloxacin

              magnesium hydroxide decreases levels of ofloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

              calcium carbonate, ofloxacin. Either decreases levels of the other by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • omadacycline

              magnesium hydroxide will decrease the level or effect of omadacycline by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Multivalent cation-containing products may impair absorption of tetracyclines, which may decrease its efficacy. Separate dosing of tetracyclines from these products.

              calcium carbonate will decrease the level or effect of omadacycline by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Multivalent cation-containing products may impair absorption of tetracyclines, which may decrease its efficacy. Separate dosing of tetracyclines from these products.

            • pamidronate

              calcium carbonate decreases levels of pamidronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 30 minutes.

            • pancrelipase

              magnesium hydroxide decreases effects of pancrelipase by pharmacodynamic antagonism. Use Caution/Monitor. Antacids may negate beneficial effects of enzymes.

            • pancrelipase

              calcium carbonate decreases effects of pancrelipase by pharmacodynamic antagonism. Use Caution/Monitor. Antacids may negate beneficial effects of enzymes.

            • penbutolol

              calcium carbonate decreases effects of penbutolol by unspecified interaction mechanism. Use Caution/Monitor.

              calcium carbonate decreases levels of penbutolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • penicillamine

              magnesium hydroxide decreases levels of penicillamine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

              calcium carbonate decreases levels of penicillamine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • perindopril

              calcium carbonate decreases effects of perindopril by unspecified interaction mechanism. Use Caution/Monitor.

            • pexidartinib

              magnesium hydroxide will decrease the level or effect of pexidartinib by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Separate pexidartinib by 2 hr before or after taking a locally-acting antacid.

            • pexidartinib

              calcium carbonate will decrease the level or effect of pexidartinib by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Separate pexidartinib by 2 hr before or after taking a locally-acting antacid.

            • pindolol

              calcium carbonate decreases effects of pindolol by unspecified interaction mechanism. Use Caution/Monitor.

              calcium carbonate decreases levels of pindolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • polysaccharide iron

              calcium carbonate will decrease the level or effect of polysaccharide iron by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • posaconazole

              calcium carbonate will decrease the level or effect of posaconazole by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • potassium phosphates, IV

              calcium carbonate decreases effects of potassium phosphates, IV by cation binding in GI tract. Modify Therapy/Monitor Closely. Calcium decreases serum phosphate concentration by binding dietary phosphate. Use alternatives if available.

            • propranolol

              calcium carbonate decreases effects of propranolol by unspecified interaction mechanism. Use Caution/Monitor.

              calcium carbonate decreases levels of propranolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • quinapril

              calcium carbonate decreases effects of quinapril by unspecified interaction mechanism. Use Caution/Monitor.

            • quinidine

              calcium carbonate will increase the level or effect of quinidine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor. Elevated quinidine plasma levels, possibly with cardiac conduction disturbances and arrhythmias, may occur.

            • ramipril

              calcium carbonate decreases effects of ramipril by unspecified interaction mechanism. Use Caution/Monitor.

            • rifampin

              calcium carbonate will decrease the level or effect of rifampin by Other (see comment). Use Caution/Monitor. Concomitant antacid administration may reduce absorption of rifampin; daily doses of rifampin should be given at least 1 hr before ingestion of antacids

            • rilpivirine

              calcium carbonate decreases levels of rilpivirine by increasing gastric pH. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Coadministration of antacids with rilpivirine may cause significant decreases in rilpivirine plasma concentrations because of increased gastric pH. If antacids must be administered, they should be given at least 2 hr before or at least 4 hr after rilpivirine. For the combination product dolutegravir/rilpivirine, antacids should be given at least 4 hr before or at least 6 hr afterwards.

            • riociguat

              magnesium hydroxide decreases levels of riociguat by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate administration by at least 1 hour.

              calcium carbonate decreases levels of riociguat by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate administration by at least 1 hour.

            • risedronate

              calcium carbonate decreases levels of risedronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 30 minutes.

            • sarecycline

              magnesium hydroxide will decrease the level or effect of sarecycline by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Multivalent cation-containing products may impair absorption of tetracyclines, which may decrease its efficacy. Separate dosing of tetracyclines from these products.

            • rose hips

              calcium carbonate will decrease the level or effect of rose hips by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • rosuvastatin

              calcium carbonate decreases levels of rosuvastatin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • sarecycline

              calcium carbonate will decrease the level or effect of sarecycline by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Multivalent cation-containing products may impair absorption of tetracyclines, which may decrease its efficacy. Separate dosing of tetracyclines from these products.

            • sodium phosphates, IV

              calcium carbonate decreases effects of sodium phosphates, IV by cation binding in GI tract. Modify Therapy/Monitor Closely. Calcium decreases serum phosphate concentration by binding dietary phosphate. Use alternatives if available.

              magnesium hydroxide decreases effects of sodium phosphates, IV by cation binding in GI tract. Modify Therapy/Monitor Closely. Magnesium decreases serum phosphate concentration by binding dietary phosphate. Use alternatives if available.

            • sodium sulfate/?magnesium sulfate/potassium chloride

              sodium sulfate/?magnesium sulfate/potassium chloride increases toxicity of calcium carbonate by Other (see comment). Use Caution/Monitor. Comment: Coadministration with medications that cause fluid and electrolyte abnormalities may increase the risk of adverse events of seizure, arrhythmias, and renal impairment.

            • vismodegib

              magnesium hydroxide will decrease the level or effect of vismodegib by Other (see comment). Use Caution/Monitor. Drugs that increase gastric pH alter vismodegib solubility and therefore reduce bioavailability; effect on efficacy unknown

            • sodium sulfate/potassium sulfate/magnesium sulfate

              sodium sulfate/potassium sulfate/magnesium sulfate increases toxicity of calcium carbonate by Other (see comment). Use Caution/Monitor. Comment: Coadministration with medications that cause fluid and electrolyte abnormalities may increase the risk of adverse events of seizure, arrhythmias, and renal impairment.

            • sofosbuvir/velpatasvir

              calcium carbonate will decrease the level or effect of sofosbuvir/velpatasvir by increasing gastric pH. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Velpatasvir solubility decreases as gastric pH increases (practically insoluble at pH >5). Separate administration of sofosbuvir/velpatasvir from antacids by at least 4 hr.

            • sotalol

              calcium carbonate decreases effects of sotalol by unspecified interaction mechanism. Use Caution/Monitor.

              calcium carbonate decreases levels of sotalol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • squill

              calcium carbonate increases toxicity of squill by unspecified interaction mechanism. Use Caution/Monitor.

            • strontium ranelate

              calcium carbonate decreases levels of strontium ranelate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Applies to oral form of calcium. Separate by 2 hr.

            • tiludronate

              calcium carbonate decreases levels of tiludronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 30 minutes.

            • timolol

              calcium carbonate decreases effects of timolol by unspecified interaction mechanism. Use Caution/Monitor.

              calcium carbonate decreases levels of timolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

            • tolbutamide

              calcium carbonate will increase the level or effect of tolbutamide by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

            • trandolapril

              calcium carbonate decreases effects of trandolapril by unspecified interaction mechanism. Use Caution/Monitor.

            • ursodiol

              calcium carbonate decreases effects of ursodiol by pharmacodynamic antagonism. Use Caution/Monitor.

            • verapamil

              calcium carbonate decreases effects of verapamil by pharmacodynamic antagonism. Use Caution/Monitor.

            • vismodegib

              calcium carbonate will decrease the level or effect of vismodegib by Other (see comment). Use Caution/Monitor. Drugs that increase gastric pH alter vismodegib solubility and therefore reduce bioavailability; effect on efficacy unknown

            • vitamin D

              vitamin D, calcium carbonate. Other (see comment). Use Caution/Monitor. Comment: The concurrent use of vitamin D with calcium salts is generally beneficial; in some patients this combination may result in hypercalcemia.

              vitamin D increases levels of magnesium hydroxide by Other (see comment). Use Caution/Monitor. Comment: Vitamin D can increase serum magnesium concentrations, particularly in the presence of renal impairment. The combined use of vitamin D and magnesium-containing products should be avoided, if possible, in patients with chronic renal failure.

            • zoledronic acid

              calcium carbonate decreases levels of zoledronic acid by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 30 minutes.

            Minor (87)

            • amikacin

              amikacin decreases levels of calcium carbonate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

              amikacin decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • amiloride

              amiloride decreases levels of calcium carbonate by increasing renal clearance. Minor/Significance Unknown.

              amiloride increases levels of magnesium hydroxide by decreasing renal clearance. Minor/Significance Unknown.

            • amphotericin B deoxycholate

              amphotericin B deoxycholate decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • aspirin

              calcium carbonate, aspirin. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

            • aspirin rectal

              calcium carbonate, aspirin rectal. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

            • aspirin/citric acid/sodium bicarbonate

              calcium carbonate, aspirin/citric acid/sodium bicarbonate. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

            • balsalazide

              calcium carbonate, balsalazide. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

            • bazedoxifene/conjugated estrogens

              bazedoxifene/conjugated estrogens decreases levels of magnesium hydroxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.

            • bendroflumethiazide

              bendroflumethiazide increases levels of calcium carbonate by decreasing renal clearance. Minor/Significance Unknown. Risk of alkalosis, hypercalcemia.

              bendroflumethiazide decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • blessed thistle

              blessed thistle decreases effects of calcium carbonate by pharmacodynamic antagonism. Minor/Significance Unknown. Theoretical interaction.

            • bumetanide

              bumetanide decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • budesonide

              budesonide decreases levels of calcium carbonate by increasing elimination. Minor/Significance Unknown.

            • bumetanide

              bumetanide decreases levels of calcium carbonate by increasing renal clearance. Minor/Significance Unknown.

            • caffeine

              caffeine decreases levels of calcium carbonate by increasing renal clearance. Minor/Significance Unknown.

            • calcitonin salmon

              calcitonin salmon increases levels of magnesium hydroxide by decreasing renal clearance. Minor/Significance Unknown.

            • calcitriol topical

              calcitriol topical increases levels of calcium carbonate by pharmacodynamic synergism. Minor/Significance Unknown. Topical calcitriol may lead to hypercalcemia.

            • carbonyl iron

              calcium carbonate decreases levels of carbonyl iron by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

              carbonyl iron increases levels of calcium carbonate by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • chlorothiazide

              chlorothiazide decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

              chlorothiazide increases levels of calcium carbonate by decreasing renal clearance. Minor/Significance Unknown. Risk of alkalosis, hypercalcemia.

            • chlorthalidone

              chlorthalidone increases levels of calcium carbonate by decreasing renal clearance. Minor/Significance Unknown. Risk of alkalosis, hypercalcemia.

              chlorthalidone decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • choline magnesium trisalicylate

              calcium carbonate, choline magnesium trisalicylate. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

            • conjugated estrogens

              conjugated estrogens decreases levels of magnesium hydroxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.

            • chromium

              calcium carbonate decreases levels of chromium by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown. Separate by 2 hours.

            • conjugated estrogens, vaginal

              conjugated estrogens, vaginal decreases levels of magnesium hydroxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.

            • cortisone

              cortisone decreases levels of calcium carbonate by increasing elimination. Minor/Significance Unknown.

            • cyclopenthiazide

              cyclopenthiazide decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

              cyclopenthiazide increases levels of calcium carbonate by decreasing renal clearance. Minor/Significance Unknown. Risk of alkalosis, hypercalcemia.

            • deflazacort

              deflazacort decreases levels of calcium carbonate by increasing elimination. Minor/Significance Unknown.

            • dextrose

              dextrose decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • devil's claw

              devil's claw decreases effects of calcium carbonate by pharmacodynamic antagonism. Minor/Significance Unknown.

            • dexamethasone

              dexamethasone decreases levels of calcium carbonate by increasing elimination. Minor/Significance Unknown.

            • dextrose (Antidote)

              dextrose (Antidote) decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • diflunisal

              calcium carbonate, diflunisal. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

            • digoxin

              digoxin decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • doxercalciferol

              doxercalciferol increases levels of magnesium hydroxide by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • drospirenone

              drospirenone increases levels of magnesium hydroxide by decreasing renal clearance. Minor/Significance Unknown.

              drospirenone decreases levels of calcium carbonate by increasing renal clearance. Minor/Significance Unknown.

            • estradiol

              estradiol decreases levels of magnesium hydroxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.

            • ethacrynic acid

              ethacrynic acid decreases levels of calcium carbonate by increasing renal clearance. Minor/Significance Unknown.

            • estrogens conjugated synthetic

              estrogens conjugated synthetic decreases levels of magnesium hydroxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.

            • estrogens esterified

              estrogens esterified decreases levels of magnesium hydroxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.

            • estropipate

              estropipate decreases levels of magnesium hydroxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.

            • ethacrynic acid

              ethacrynic acid decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • ferric maltol

              ferric maltol increases levels of calcium carbonate by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

              calcium carbonate decreases levels of ferric maltol by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • ferrous fumarate

              calcium carbonate decreases levels of ferrous fumarate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

              ferrous fumarate increases levels of calcium carbonate by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • ferrous gluconate

              ferrous gluconate increases levels of calcium carbonate by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

              calcium carbonate decreases levels of ferrous gluconate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • ferrous sulfate

              ferrous sulfate increases levels of calcium carbonate by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • fludrocortisone

              fludrocortisone decreases levels of calcium carbonate by increasing elimination. Minor/Significance Unknown.

            • furosemide

              furosemide decreases levels of calcium carbonate by increasing renal clearance. Minor/Significance Unknown.

              furosemide decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • gentamicin

              gentamicin decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

              gentamicin decreases levels of calcium carbonate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • glucagon intranasal

              glucagon intranasal increases levels of magnesium hydroxide by decreasing renal clearance. Minor/Significance Unknown.

            • hydrochlorothiazide

              hydrochlorothiazide increases levels of calcium carbonate by decreasing renal clearance. Minor/Significance Unknown. Risk of alkalosis, hypercalcemia.

            • hydrochlorothiazide

              hydrochlorothiazide decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • hydrocortisone

              hydrocortisone decreases levels of calcium carbonate by increasing elimination. Minor/Significance Unknown.

            • ibandronate

              magnesium hydroxide decreases levels of ibandronate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • indapamide

              indapamide increases levels of calcium carbonate by decreasing renal clearance. Minor/Significance Unknown. Risk of alkalosis, hypercalcemia.

              indapamide decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • iron dextran complex

              calcium carbonate decreases levels of iron dextran complex by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

              iron dextran complex increases levels of calcium carbonate by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • mannitol

              mannitol decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • iron sucrose

              calcium carbonate decreases levels of iron sucrose by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

              iron sucrose increases levels of calcium carbonate by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • isoniazid

              isoniazid decreases levels of calcium carbonate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • isotretinoin

              isotretinoin increases levels of calcium carbonate by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • lily of the valley

              calcium carbonate increases effects of lily of the valley by unspecified interaction mechanism. Minor/Significance Unknown.

            • manganese

              calcium carbonate, manganese. Either decreases levels of the other by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown. Separate by 2 hours.

            • mesalamine

              calcium carbonate, mesalamine. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

            • mestranol

              mestranol decreases levels of magnesium hydroxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.

            • methyclothiazide

              methyclothiazide increases levels of calcium carbonate by decreasing renal clearance. Minor/Significance Unknown. Risk of alkalosis, hypercalcemia.

              methyclothiazide decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • methylprednisolone

              methylprednisolone decreases levels of calcium carbonate by increasing elimination. Minor/Significance Unknown.

            • metolazone

              metolazone decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • metolazone

              metolazone increases levels of calcium carbonate by decreasing renal clearance. Minor/Significance Unknown. Risk of alkalosis, hypercalcemia.

            • neomycin PO

              neomycin PO decreases levels of calcium carbonate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

              neomycin PO decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • nitrofurantoin

              magnesium hydroxide decreases levels of nitrofurantoin by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • paromomycin

              paromomycin decreases levels of calcium carbonate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • paromomycin

              paromomycin decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • polysaccharide iron

              calcium carbonate decreases levels of polysaccharide iron by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

              polysaccharide iron increases levels of calcium carbonate by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • prednisolone

              prednisolone decreases levels of calcium carbonate by increasing elimination. Minor/Significance Unknown.

            • prednisone

              prednisone decreases levels of calcium carbonate by increasing elimination. Minor/Significance Unknown.

            • rose hips

              calcium carbonate decreases levels of rose hips by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

              rose hips increases levels of calcium carbonate by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • salicylates (non-asa)

              calcium carbonate, salicylates (non-asa). Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

            • salsalate

              calcium carbonate, salsalate. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

            • shark cartilage

              calcium carbonate, shark cartilage. pharmacodynamic synergism. Minor/Significance Unknown. May lead to hypercalcemia (theoretical).

            • sodium polystyrene sulfonate

              sodium polystyrene sulfonate increases levels of magnesium hydroxide by decreasing renal clearance. Minor/Significance Unknown. Risk of alkalosis.

              sodium polystyrene sulfonate increases levels of calcium carbonate by decreasing renal clearance. Minor/Significance Unknown. Risk of alkalosis.

            • spironolactone

              spironolactone decreases levels of calcium carbonate by increasing renal clearance. Minor/Significance Unknown.

              spironolactone increases levels of magnesium hydroxide by decreasing renal clearance. Minor/Significance Unknown.

            • streptomycin

              streptomycin decreases levels of calcium carbonate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

              streptomycin decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • sulfasalazine

              calcium carbonate, sulfasalazine. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

            • tobramycin

              tobramycin decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

            • teriparatide

              teriparatide increases levels of calcium carbonate by pharmacodynamic synergism. Minor/Significance Unknown.

            • tobramycin

              tobramycin decreases levels of calcium carbonate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

            • torsemide

              torsemide decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

              torsemide decreases levels of calcium carbonate by increasing renal clearance. Minor/Significance Unknown.

            • triamcinolone acetonide injectable suspension

              triamcinolone acetonide injectable suspension decreases levels of calcium carbonate by increasing elimination. Minor/Significance Unknown.

            • triamterene

              triamterene increases levels of magnesium hydroxide by decreasing renal clearance. Minor/Significance Unknown.

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            Adverse Effects

            Frequency Not Defined

            Calcium carbonate

            • Anorexia
            • Constipation
            • Flatulence
            • Nausea
            • Vomiting
            • Hypercalcemia
            • Hypophosphatemia
            • Xerostomia
            • Acid rebound
            • Milk-alkali syndrome

            Magnesium hydroxide

            • Nausea
            • Constipation
            • Vomiting
            • Hypotension
            • Respiratory depression
            • Diarrhea
            • Abdominal crampin
            • Electrolyte imbalance
            • Muscle weakness
            • Parageusia
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            Warnings

            Contraindications

            Calcium carbonate

            • Hypersensitivity
            • Hypercalciuria
            • Renal calculi
            • Hypophosphatemia
            • Hypercalcemia
            • Suspected digoxin toxicity

            Magnesium hydroxide

            • Hypersensitivity
            • Renal failure
            • Existing electrolyte imbalance
            • Appendicitis symptoms
            • Acute surgical abdomen
            • Myocardial damage
            • Heart block
            • Fecal impaction
            • Rectal fissures
            • Intestinal obstruction or perforation

            Cautions

            OTC use: Do not use the maximum dosage for >2 weeks; if symptoms persist, discontinue and contact a health care provider

            Magnesium hydroxide: Caution with neuromuscular disease (eg, myasthenia gravis) and renal insufficiency

            Calcium carbonate: Caution with a history of kidney stones; Ca oxalate formation may increase risk

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            Pregnancy & Lactation

            Pregnancy Category: C (calcium carbonate); B (magnesium hydroxide)

            Calcium and magnesium both cross the placenta; antacids containing calcium or magnesium are considered to be low risk during pregnancy, however avoid excessive use

            Supplement calcium and magnesium during pregnancy and lactation according to recommended daily allowance

            Lactation: Calcium and magnesium both appear in breast milk, use in nursing mothers appears to be safe

            Pregnant or breastfeeding patients should seek advice of health professional before using OTC drugs

            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.

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            Pharmacology

            Mechanism of Action

            Antacid: Neutralizes gastric secretions resulting in increased gastric pH

            Absorption

            Onset of antacid action dependent on gastric emptying time

            Bioavailability: 25-35% (calcium carbonate); 15-30% (magnesium hydroxide)

            Distribution

            Protein bound: 45% (calcium carbonate)

            Elimination

            Excretion

            • Calcium carbonate: 80% as unabsorbed calcium in feces, 20% via urine
            • Magnesium hydroxide: Primarily via urine
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            Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.