Antacids (Monograph)
Brand names: Alamag, Alamag Plus, Alka-Mints, Alka-Seltzer Gold Effervescent Antacid, Almacone,
... show all 56 brands
Drug class: Antacids and Adsorbents
- Antiulcer Agents
ATC class: A02A
VA class: GA209
CAS number: 53547-27-6
Introduction
Inorganic salts that partially neutralize gastric hydrochloric acid.
Uses for Antacids
Peptic Ulcers
Adjunct to other drugs (e.g., anti-infectives, histamine H2-receptor antagonists, proton-pump inhibitors) for the relief of peptic ulcer pain and to promote the healing of peptic ulcers.
Because of the inconvenience of the regimens needed to promote ulcer healing, high recurrence rate, ineffectiveness in eradicating Helicobacter pylori, palatability issues, and adverse effects, antacids rarely are used alone any longer for the treatment of peptic ulcer disease. Instead, antacids currently are used principally as an adjunct to other antiulcer regimens for as-needed (prn) relief of peptic ulcer pain.
Acid Indigestion
Self-medication for the relief of acid indigestion (dyspepsia), heartburn, and sour stomach and/or bloating (commonly referred as gas).
Gastroesophageal Reflux Disease (GERD)
Self-medication for the relief of mild forms of GERD (e.g., symptoms induced by a heartburn-inducing meal).
Antacids generally provide more rapid but less prolonged relief of GERD symptoms compared with histamine H2-receptor antagonists, and combined therapy generally is more effective than either class of drugs alone.
Consult a clinician if symptoms persist or warning signs of more severe GERD develop (e.g., dysphagia, bleeding, weight loss, choking [acid-induced cough, shortness of breath, and/or hoarseness], chest pain).
Other agents (e.g., histamine H2-receptor antagonists, proton-pump inhibitors) preferred by American College of Gastroenterology (ACG) and American Gastroenterological Association (AGA) for management of more severe forms of GERD.
Have been used for self-medication for the relief of breakthrough symptoms in patients receiving proton-pump inhibitors.
Hyperphosphatemia
Aluminum-containing antacids (except aluminum phosphate): Management of hyperphosphatemia or prevention of recurrent phosphatic renal calculi (in conjunction with a low phosphate diet).
Aluminum carbonate generally preferred to aluminum hydroxide for this use.
Calcium Replacement
Calcium carbonate is used for calcium supplementation.
Stress Ulceration and GI Bleeding
Has been used for prevention of stress ulceration† [off-label] and GI bleeding† [off-label].
Gastric Acid Aspiration
Has been used for prevention of gastric acid aspiration† [off-label] in patients undergoing cesarean section or emergency surgery; generally has been replaced by histamine H2-receptor antagonist or citrate solution.
Antacids Dosage and Administration
Administration
Oral Administration
Administer orally.
Oral suspensions more rapidly and effectively solubilized than powders or tablets; reserve oral tablets for chronic use in patients who refuse oral suspensions because of inconvenience or unpalatable taste. Rapidly disintegrating tablets may be a suitable alternative in some patients.
Chew tablets, including rapidly dissolving tablets, thoroughly before swallowing.
Dosage
Available as various inorganic salts (e.g., aluminum carbonate, aluminum hydroxide, calcium carbonate, magnesium hydroxide, magnesium oxide, sodium bicarbonate); dosage is expressed in terms of mEq of acid neutralizing capacity.
Dose and frequency of administration depend on the acid secretory rate of the stomach, gastric emptying time, and the disorder being treated.
Adults
Peptic Ulcers
For peptic ulcer disease, dosages of antacids are empirical and various antacid dosages have been used.
Adjunctive Therapy
OralFor supplemental ulcer pain relief, 40–80 mEq acid neutralizing capacity on an as-needed (prn) basis.
Treatment
OralOther therapies currently are preferred for treatment of active peptic ulcers. (See Peptic Ulcers under Uses.)
If antacids are used for the treatment of peptic ulcers, usual high-dose regimens for ulcer healing employ 80–160 mEq acid neutralizing capacity, given 1 and 3 hours after meals and at bedtime.
Additional doses of antacids may be administered to relieve ulcer pain that occurs between regularly scheduled doses.
In patients with duodenal ulcers, antacids usually are given for 4–6 weeks. If symptoms of duodenal ulcer recur, antacids can be administered 1 and 3 hours after meals and at bedtime for 1 week and, if pain is relieved, less frequently for an additional 1–2 weeks.
In patients with gastric ulcers, antacids are administered until healing is complete.
Gastroesophageal Reflux Disease (GERD)
For GERD, dosages of antacids are empirical and various antacid dosages have been used.
Oral
For relief of heartburn, one recommended regimen employs 40–80 mEq acid neutralizing capacity on an as-needed (prn) basis intially. If necessary, dosage can be titrated to a regularly scheduled basis such as 40–80 mEq acid neutralizing capacity given after meals and at bedtime.
Hyperphosphatemia
Oral
In conjunction with dietary phosphate restriction in the management of hyperphosphatemia, 30–40 mL of aluminum hydroxide or aluminum carbonate suspension is administered 3 or 4 times daily.
Stress Ulceration and GI Bleeding
Oral
In the management of stress ulceration† [off-label] and GI bleeding† [off-label], antacids are usually administered every hour, and the antacid dosage should be titrated to maintain the nasogastric aspirate above pH 3.5.
For severe symptoms, antacid suspensions may be diluted with water or milk and given by continuous intragastric infusion.
Gastric Acid Aspiration
Oral
To reduce the risk of anesthesia-induced gastric acid aspiration, an antacid suspension has been given 30 minutes before anesthesia.
Prescribing Limits
Adults
GERD
Oral
Do not exceed 500–600 mEq acid neutralizing capacity daily or regularly scheduled (versus as-needed; prn) therapy for longer than 2 weeks continuously.
Sodium Bicarbonate
Maximum daily dosage of sodium or bicarbonate is 200 mEq in patients <60 years of age and 100 mEq in patients >60 years of age. Contraindicated for prolonged therapy because it may cause metabolic alkalosis or sodium overload.
Cautions for Antacids
Contraindications
-
Sodium bicarbonate is contraindicated and use of other sodium-containing antacids should be restricted in patients on low-sodium diets and in those with CHF, renal failure, edema, or cirrhosis.
Warnings/Precautions
Warnings
Phenylketonuria
Some antacids may contain aspartame (e.g., NutraSweet), which is metabolized in the GI tract to phenylalanine following oral administration.
Sensitivity Reactions
Tartrazine Sensitivity
Some antacid formulations contain the dye tartrazine (FD&C yellow No. 5), which may cause allergic-type reactions (bronchial asthma in susceptible individuals) in certain susceptible individuals (e.g., patients who are sensitive to aspirin).
General Precautions
Aluminum Antacids
Risk of hypophosphatemia with prolonged administration or large doses, particularly in patients with inadequate dietary intake of phosphorus.
Monitor serum phosphate concentrations at monthly or bimonthly intervals in patients on maintenance hemodialysis who are receiving chronic aluminum antacid therapy.
Calcium Carbonate
May cause gastric hypersecretion and acid rebound.
May cause the milk-alkali syndrome (characterized by hypercalcemia, metabolic alkalosis and, rarely, renal insufficiency).
Monitor serum calcium concentrations weekly and whenever manifestations of hypercalcemia occur in patients receiving large doses of calcium carbonate.
Magnesium Antacids
Commonly cause a laxative effect, and frequent administration of these antacids alone often cannot be tolerated; repeated doses cause diarrhea which may cause fluid and electrolyte imbalances.
Sodium Bicarbonate
May cause metabolic alkalosis when given in large doses.
Medication Errors
Serious medication errors have been reported to FDA in which consumers used Maalox Total Relief (bismuth subsalicylate) when they intended to use traditional Maalox liquid antacid products containing aluminum hydroxide, magnesium hydroxide, and simethicone (e.g., Maalox Advanced Regular Strength, Maalox Advanced Maximum Strength). Because of the potential for serious adverse effects associated with accidental use of bismuth subsalicylate (which is chemically related to aspirin), the manufacturer of Maalox Total Relief initially agreed to change the trade name of the product to one that did not include “Maalox”; however, the manufacturer instead discontinued the bismuth subsalicylate preparation in the summer of 2010.
Specific Populations
Renal Impairment
Aluminum Antacids: Long-term administration in patients with renal failure or chronic renal failure may result in hyperaluminemia since small amounts of aluminum are absorbed from the GI tract and excretion of aluminum is decreased in patients with renal failure. Aluminum accumulation in the CNS may be the cause of dialysis encephalopathy, while aluminum accumulation in the bones may result in or worsen dialysis osteomalacia.
Calcium Carbonate: Patients with renal impairment or dehydration and electrolyte imbalance are predisposed to developing the milk-alkali syndrome. Hypercalcemia risk in chronic hemodialysis patients.
Magnesium Antacids: In patients with severe renal impairment, hypermagnesemia characterized by hypotension, nausea, vomiting, ECG changes, respiratory or mental depression, and coma. Do not administer in patients with renal failure, and antacids containing more than 50 mEq of magnesium in the recommended daily dosage should be used cautiously and only under the supervision of a clinician who should monitor electrolytes in patients with renal disease.
Sodium Bicarbonate: May cause metabolic alkalosis in patients with renal insufficiency.
Common Adverse Effects
With prolonged administration, constipation (e.g., aluminum salts, calcium carbonate), diarrhea (e.g., magnesium salts), gastric distension/flatulence (e.g., sodium bicarbonate), and gastric hypersecretion/acid rebound (e.g., calcium carbonate).
Drug Interactions
All antacids potentially may increase or decrease the rate and/or extent of absorption of concomitantly administered oral drugs by changing GI transit time or by binding or chelating the drug. In vitro studies indicate that magnesium hydroxide or trisilicate has the greatest potential for drug binding and aluminum hydroxide and calcium carbonate are intermediate.
Specific Drugs and Food
Drug |
Interaction |
Comments |
---|---|---|
Aspirin |
Pharmacokinetic (increased absorption of buffered or enteric-coated aspirin or decreased blood salicylate concentrations) interactions |
|
Chlordiazepoxide |
Possible decreased chlordiazepoxide absorption with aluminum hydroxide and magnesium preparations |
|
Diazepam |
Possible increased diazepam absorption with aluminum hydroxide |
|
Digoxin |
Possible decreased digoxin absorption |
Space doses of the drugs as far apart as possible |
Indomethacin |
Possible decreased indomethacin absorption |
Space doses of the drugs as far apart as possible |
Iron salts |
Possible decreased absorption of iron salts |
Space doses of the drugs as far apart as possible |
Isoniazid |
Possible decreased isoniazid absorption with aluminum hydroxide |
Administer isoniazid at least 1 hour before aluminum-containing antacids |
Milk or other calcium-containing foods |
Possible milk-alkali syndrome with chronic administration of bicarbonate and milk or calcium |
|
Naproxen |
Possible increased naproxen absorption with sodium bicarbonate Possible decreased naproxen absorption with magnesium oxide or aluminum hydroxide |
|
Pseudoephedrine |
Possible increased pseudoephedrine absorption with aluminum hydroxide |
|
Tetracyclines |
Possible decreased tetracycline absorption |
Allow 1–2 hours to elapse between doses of antacids and tetracyclines |
Actions
-
Mechanism of action in the treatment of peptic ulcers is based on ability of antacids to react with hydrochloric acid and thus increase gastric pH.
-
With usual doses, antacids generally do not increase and maintain gastric pH above 4–5.
-
Antacids, in decreasing order of their ability to neutralize a given amount of acid, are calcium carbonate, sodium bicarbonate, magnesium salts, and aluminum salts.
-
Aluminum-containing antacids (except aluminum phosphate) combine with dietary phosphate in the intestine forming insoluble, nonabsorbable aluminum phosphate which is excreted in the feces. If phosphate intake is limited and renal function is normal, aluminum antacids (except aluminum phosphate) decrease phosphate absorption and hypophosphatemia and hypophosphaturia occur.
-
Magnesium-containing antacids have a laxative action.
Advice to Patients
-
Advise patients to consult a clinician if ulcer pain worsens or is not relieved after the first week of therapy.
-
Importance of consulting a clinician if GERD symptoms persist or warning signs of more severe GERD develop (e.g., dysphagia, bleeding, weight loss, choking [acid-induced cough, shortness of breath, and/or hoarseness], chest pain).
-
Importance of women informing their clinician if they are or plan to become pregnant or plan to breast-feed.
-
Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as concomitant illnesses.
-
Importance of informing patients of other important precautionary information. (See Cautions.)
Preparations
Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.
Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Oral |
Capsules |
equivalent to dried aluminum hydroxide gel 608 mg or aluminum hydroxide 500 mg |
Basaljel |
Wyeth |
Tablets |
equivalent to dried aluminum hydroxide gel 608 mg or aluminum hydroxide 500 mg |
Basaljel (scored) |
Wyeth |
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Oral |
Capsules |
475 mg |
Alu-Cap |
3M |
Suspension |
320 mg/5 mL* |
Aluminum Hydroxide Suspension |
||
Amphojel |
Wyeth |
|||
600 mg/5 mL |
ALternaGEL |
J&J-Merck |
||
Tablets |
300 mg |
Amphojel |
Wyeth |
|
Tablets, film-coated |
600 mg |
Alu-Tab |
3M |
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Bulk |
Powder* |
|||
Oral |
Pieces, chewing gum |
500 mg |
Chooz |
Insight |
Suspension |
400 mg/5 mL |
Mylanta Children’s Upset Stomach Relief |
J&J-Merck |
|
1.25 g/5 mL* |
Calcium Carbonate Suspension |
|||
Tablets |
1.25 g* |
Calcium Carbonate Tablets (scored) |
||
Tablets, chewable |
400 mg |
Mylanta Children’s Upset Stomach Relief |
J&J-Merck |
|
420 mg |
Titralac Regular |
3M |
||
500 mg |
Tums Antacid/Calcium Supplement |
GlaxoSmithKline |
||
650 mg* |
Calcium Carbonate Chewable Tablets |
|||
750 mg |
Titralac Extra Strength |
3M |
||
Tums E-X Antacid/Calcium Supplement |
GlaxoSmithKline |
|||
850 mg |
Alka-Mints |
Bayer |
||
1 g |
Tums Ultra Antacid/Calcium Supplement |
GlaxoSmithKline |
||
Tablets, chewable, rapidly disintegrating |
600 mg |
Maalox Quick Dissolve Chewables |
Novartis |
|
1 g |
Maalox Quick Dissolve Chewables Maximum Strength |
Novartis |
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Bulk |
Powder* |
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Oral |
Suspension |
540 mg/5 mL |
Lowsium |
Rugby |
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Oral |
Suspension |
540 mg/5 mL with Simethicone 40 mg/5 mL |
Lowsium Plus |
Rugby |
Riopan Plus |
Wyeth |
|||
1080 mg/5 mL with Simethicone 40 mg/5mL |
Riopan Plus Double Strength |
Wyeth |
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Bulk |
Powder* |
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Bulk |
Powder* |
|||
Oral |
Suspension |
400 mg/5 mL* |
Milk of Magnesia |
|
Phillips’ Milk of Magnesia |
Bayer |
|||
800 mg/5 mL |
Phillips’ Milk of Magnesia Concentrate |
Bayer |
||
1.2 g/5 mL* |
Milk of Magnesia Concentrate |
Roxane |
||
Tablets |
300 mg* |
Phillips’ Milk of Magnesia |
Bayer |
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Bulk |
Powder* |
|||
Oral |
Capsules |
140 mg |
Uro-Mag |
Blaine |
Tablets |
400 mg* |
Magnesium Oxide Tablets |
||
Mag-Ox 400 |
Blaine |
|||
420 mg* |
Magnesium Oxide Tablets |
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Bulk |
Powder* |
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Bulk |
Powder* |
|||
Oral |
For solution |
0.78 g/3.9 g |
Citrocarbonate Granules |
Lee |
Tablets |
325 mg* |
Sodium Bicarbonate Tablets |
||
650 mg* |
Sodium Bicarbonate Tablets |
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Oral |
Suspension |
Aluminum Hydroxide 31.7 mg/5 mL and Magnesium Carbonate 119.3 mg/5 mL |
Gaviscon Liquid |
GlaxoSmithKline |
Genaton Liquid |
Teva |
|||
Aluminum Hydroxide 254 mg/5 mL and Magnesium Carbonate 237.5 mg/5 mL |
Gaviscon Extra Strength |
GlaxoSmithKline |
||
Tablets, chewable |
Aluminum Hydroxide 160 mg and Magnesium Carbonate 105 mg |
Gaviscon Extra Strength |
GlaxoSmithKline |
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Oral |
Suspension |
Aluminum Hydroxide 200 mg/5 mL and Magnesium Hydroxide 200 mg/5 mL |
Mag-Al |
Pharmaceutical Associates |
Aluminum Hydroxide 225 mg/5 mL and Magnesium Hydroxide 200 mg/5 mL |
Alamag |
Teva |
||
Maalox |
Novartis |
|||
Rulox |
Rugby |
|||
Aluminum Hydroxide 600 mg/5 mL and Magnesium Hydroxide 300 mg/5 mL |
Maalox TC |
Novartis |
||
Tablets, chewable |
Aluminum Hydroxide 200 mg and Magnesium Hydroxide 200 mg |
Rulox #1 |
Rugby |
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Oral |
Suspension |
Aluminum Hydroxide 200 mg/5 mL, Magnesium Hydroxide 200 mg/5 mL, and Simethicone 20 mg/5 mL |
Almacone |
Rugby |
Di-Gel |
Schering-Plough |
|||
Maalox Advanced Regular Strength |
Novartis |
|||
Mag-Al Plus |
Pharmaceutical Associates |
|||
Mygel |
Sandoz |
|||
Mylanta Fast-Acting |
J&J-Merck |
|||
Aluminum Hydroxide 225 mg/5 mL, Magnesium Hydroxide 200 mg/5 mL, and Simethicone 25 mg/5 mL |
Alamag Plus |
Teva |
||
Aluminum Hydroxide 400 mg/5 mL, Magnesium Hydroxide 400 mg/5 mL, and Simethicone 40 mg/5 mL |
Almacone II Hi-Potency |
Rugby |
||
Antacid Double Strength |
Teva |
|||
Maalox Advanced Maximum Strength |
Novartis |
|||
Mag-Al XS |
Pharmaceutical Associates |
|||
Mygel II |
Sandoz |
|||
Mylanta Fast-Acting Double Strength |
J&J-Merck |
|||
Aluminum Hydroxide 500 mg/5 mL, Magnesium Hydroxide 450 mg/5 mL, and Simethicone 40 mg/5 mL |
Kudrox |
Schwarz |
||
Maalox Antacid/Anti-Gas Maximum Strength |
Novartis |
|||
Tablets, chewable |
Aluminum Hydroxide 200 mg, Magnesium Hydroxide 200 mg, and Simethicone 20 mg |
Almacone |
Rugby |
|
Aluminum Hydroxide 200 mg, Magnesium Hydroxide 200 mg, and Simethicone 25 mg |
Tempo |
Blairex |
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Oral |
Tablets, chewable |
Aluminum Hydroxide 80 mg and Magnesium Trisilicate 20 mg |
Gaviscon |
GlaxoSmithKline |
Genaton |
Teva |
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Oral |
Suspension |
Calcium Carbonate 520 mg/5 mL and Magnesium Carbonate 400 mg/5 mL |
Marblen |
Fleming |
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Oral |
Suspension |
Calcium Carbonate 400 mg/5 mL and Magnesium Hydroxide 135 mg/5 mL |
Mylanta Supreme Fast Acting |
J&J-Merck |
Tablets |
Calcium Carbonate 550 mg and Magnesium Hydroxide 125 mg |
Mylanta Gelcaps |
J&J-Merck |
|
Tablets, chewable |
Calcium Carbonate 350 mg and Magnesium Hydroxide 150 mg |
Mylanta Fast-Acting |
J&J-Merck |
|
Calcium Carbonate 500 mg and Magnesium Hydroxide 110 mg |
Rolaids Antacid |
Pfizer |
||
Calcium Carbonate 700 mg and Magnesium Hydroxide 300 mg |
Mylanta Fast-Acting Maximum Strength |
J&J-Merck |
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Oral |
Tablets |
Calcium Carbonate 280 mg, Magnesium Hydroxide 128 mg, and Simethicone 20 mg |
Di-Gel |
Schering-Plough |
Tablets, chewable |
Calicum Carbonate 800 mg, Magnesium Hydroxide 165 mg, and Famotidine 10 mg |
Pepcid Complete |
J&J-Merck |
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Oral |
Tablets |
420 mg with Simethicone 21 mg |
Titralac Plus |
3M |
Tablets, chewable, rapidly disintegrating |
1 g with Simethicone 60 mg |
Maalox Max Quick Dissolve Chewables Antacid/Antigas Maximum Strength |
Novartis |
Routes |
Dosage Forms |
Strengths |
Brand Names |
Manufacturer |
---|---|---|---|---|
Oral |
Tablets, for solution |
Potassium Bicarbonate 312 mg and Sodium Bicarbonate 958 mg |
Alka-Seltzer Gold Effervescent Antacid |
Bayer |
AHFS DI Essentials™. © Copyright 2024, Selected Revisions February 1, 2011. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.
† Off-label: Use is not currently included in the labeling approved by the US Food and Drug Administration.