Drugs in this Class
Aluminum Hydroxide Suspension (Alternagel Suspension)
Magaldrate Oral Suspension (Ron Acid Liquid)
Sodium Bicarbonate Tablets ()
Aluminum and Magnesium Hydroxide Oral Suspension (Alamag Suspension, Alumina and Magnesia Suspension, Mag-Al Suspension, Mylanta Ultimate Strength Suspension, Rulox Suspension)
Calcium Carbonate Tablets (Amitone Tablets, Calcarb Tablets, Caltrate 600 Tablets, Dicarbosil Tablets, Mallamint Tablets, Oyster Shell Calcium Tablets, Titralac Tablets, Tums Tablets)
Magnesium Gluconate Tablets (Mag-G Tablets, Magtrate Tablets)
Magnesium Hydroxide Oral Suspension (Milk of Magnesia, Milk of Magnesia-Concentrated, Phillips Milk of Magnesia)

Summarizing the Evidence

• In clinical studies, when antacids were compared to placebo (sugar pill), improvement of GERD symptoms was not always greater with antacid use versus placebo use. Regardless, antacids can typically be used as a first-line therapy for mild, occasional GERD symptoms.

• Antacids are not as effective for treating more moderate or severe forms of GERD (where symptoms occur more frequently and are more problematic).

• Most antacid products will effectively relieve mild GERD symptoms if taken in the appropriate doses. However, potency differs between antacid products. This means that one teaspoonful of "Antacid A" may not equal one teaspoonful of "Antacid B." The potency of antacids is expressed in terms of milli-equivalents (mEq) of Acid-Neutralizing Capacity (ANC), which means the amount of stomach acid neutralized by the antacid per dose over a specified period of time. The neutralizing capacities (or ANC) of antacid products vary considerably, depending on the product's ingredient(s) amounts, formulation, and manufacturer.

• The goal ANC dose is 40 to 80mEq to provide adequate acid neutralization. Therefore, to obtain an 80mEq ANC, you would have to take 6 teaspoonfuls of Maalox versus 20 teaspoonfuls of Gaviscon. Likewise, it would take 7 tablets of Mylanta versus 10 tablets of Rolaids to get an 80mEq ANC dose (refer to the chart below). The desired product is one that has a high ANC contained in a small dosage volume or number of tablets. Many of these doses will exceed directions printed on the antacid product labeling. Antacids used at higher than recommended doses can cause serious side effects. Therefore, you should seek the advice of your doctor or pharmacist to find an appropriate product and dose for you if label-recommended doses don't adequately control your symptoms.

• Check with your doctor or pharmacist before you choose an over the counter antacid during pregnancy or while breastfeeding. Some antacids, such as sodium bicarobonate and certain magnesium containing antacids may not be safe or only recommended for short periods of time.

• Aluminum containing antacids in the elderly are not recommended in those with bone problems or Alzheimer's disease. Check with your doctor or pharmacist before starting a new over the counter antacid product.

Compare Antacid Dosages Needed to Equal an 80 mEq ANC

**Typically, combination antacid products containing aluminum-magnesium work best and have the least amount of side effects.

Dosing and Administration

• For self-management of occasional heartburn or mild GERD symptoms, you should follow the directions written on the antacid product labeling. If heartburn symptoms become more frequent or last longer than 2 weeks, you may require higher doses (as detailed in the chart above) and/or more frequent dosing (typically four times daily--after meals and at bedtime). Sometimes, these higher doses will exceed package label recommendations. Therefore, you should contact you doctor for specific recommendations.

Tips for Antacid Selection & Usage

• Chewable Tablets: Chew thoroughly before swallowing. Follow with a glass of water.

• Effervescent Tablets: Allow to completely dissolve in water. Allow most of the bubbling to stop before drinking.

• Product Choice: Liquid products work faster, are generally more effective, and are easier to take than other dosage forms. Tablets and gums may be more acceptable and convenient for some patients.

• Refrigeration of liquid antacids may improve the flavor (but avoid freezing). If the taste of one antacid product is not satisfactory, talk to your doctor or pharmacist about switching to another product.

• Antacids reduce acidity in the stomach for about 30 minutes when taken on an empty stomach. Acidity is reduced for about 3 hours when antacids are taken 1 hour after meals. Therefore, it is best to take antacids after meals.

• To help avoid or reduce drug interactions, do not take other medications within 1 to 2 hours of taking an antacid.

• Notify your doctor if you vomit "coffee-ground" like material or experience black, tarry stools. These could be signs of stomach or intestinal bleeding, which warrants further examination by your doctor.

• Aluminum or calcium containing antacid products can sometimes cause constipation. Magnesium containing antacids products can sometimes cause diarrhea. Therefore, antacid products that combine either aluminum or calcium with magnesium may be better tolerated because the side effects cancel eachother out.

• Taking too much antacid can cause the stomach to secrete excess acid. It is important to contact your doctor or pharmacist about the appropriate dose for you.

• Do not take antacids for longer than 2 weeks unless under the advice and supervision of your physician.

Generic Availability

• Most antacids are available without a prescription in less expensive store brand versions.

Drug Interactions

Some interactions between medications can be more severe than others. The best way for you to avoid harmful interactions is to tell your doctor and/or pharmacist what medications you are currently taking, including any over-the-counter products, vitamins, and herbals. For specific information on how the drugs interact and the severity of the interaction, please use our Drug Interactions Checker.

Side Effects

To view specific side effect information, please use our Side Effect Checker.

Additional Information

Referfences:

1. Berardi RR, Kroon L, McDermott JH and Newton GD. Handbook of Nonprescription Drugs. 15th edition. Acid-Peptic Products. American Pharmaceutical Association; Washington DC. 2006.

2. Knodel LC, ed. Nonprescription Products: Formulations and Features '98-99. Acid-Peptic Products. American Pharmaceutical Association; Washington DC. 1998. pg: 162.

3. Berardi RR, Welage LS. Peptic Ulcer Disease. In: Pharmacotherapy A Pathophysiologic Approach. 6th ed. Dipiro JT, Talbert RL, Yee GC et al. (eds). McGraw-Hill. New York. 2005. pg. 629-648.

4. Drugdex Database. In: Thomson-Micromedex. Greenwood Village, CO. 2006.

5. Drug Facts and Comparisons. Wolters Kluwer Health. St. Louis, MO; 2007.

6. Graham DY & Patterson DJ: Double-blind comparison liquid antacid and placebo in the treatment of symptomatic reflux esophagitis. Dig Dis Sci 1983; 28:559-563.

7. Rhodes J: Esophagitis and the role of antacid therapy. Scand J Gastroenterol 1982; 17(suppl 75):74-76.

8. Hasan SS: Treatment of moderate to severe gastro-esophageal reflux with an alginate/antacid combination. Curr Med Res Opin 1980; 6:645-648.

9. 9. Richter JE. Review article: the management of heartburn in pregnancy. Aliment Pharmacol Ther. 2005 Nov 1;22(9):749-57 Available from URL: http://web.ebscohost.com.stlcopisa.stlcop.edu/ehost/pdf?vid=2&hid=117&sid=4ce19333-407b-44dc-98f8-2622aef16f7d%40sessionmgr103. Accessed February 2008.

Last Updated: March 2008

Note: The above information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist, or other healthcare professional. It should not be construed to indicate that the use of the product is safe, appropriate, or effective for you. Consult your healthcare professional before taking any medication.

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