Which antacid is good after meals

AntacidsAntacids are active ingredients that neutralize gastric acid, raise the gastric pH and relieve acid-related symptoms. They are mainly used for stomach burns, acid regurgitation (GERD) and indigestion. Antacids can be given after meals or when needed. In general, two hours should be allowed between taking other drugs because antacids can inhibit their absorption. For self-medication, the duration of therapy is limited to two weeks. Possible adverse effects include a change in the consistency of the stool. Disturbances of the mineral balance occur mainly in the case of renal insufficiency, long-term use or an overdose.

synonymous: antacid


Antacids are available in the form of lozenges, chewable tablets, powder and gel (suspension) for oral use. Well-known brands in Switzerland are, for example, Rennie®, Alucol® and Riopan®. The first medicines were developed as early as the 19th century.

Structure and properties

The drugs contain active ingredients that bind and neutralize stomach acid. These include, for example, carbonates such as calcium carbonate and magnesium carbonate, hydroxides such as magnesium hydroxide and oxides such as aluminum oxide. They are bases.

Example magnesium hydroxide:

Example sodium hydrogen carbonate:

Only with sodium hydrogen carbonate is the gas carbon dioxide formed, which can cause undesirable effects.


Antacid (ATC A02A) neutralize the stomach acid and lead to an increase in the pH of the stomach, which alleviates the symptoms. Some antacids also form a protective film on the stomach lining and neutralize other components of the digestive juice such as pepsin and bile acids.


Antacids are used for the symptomatic treatment of burning stomach, acid regurgitation, and gastroesophageal reflux disease. Indications also include indigestion and a feeling of pressure and fullness in the stomach area.

In some countries, antacids are also released for the symptomatic treatment of gastric and intestinal ulcers. Another area of ​​application is stomach protection while taking NSAIDs. Today, however, proton pump inhibitors are mainly used for this purpose.


According to the specialist information. Antacids are usually taken regularly after meals or as needed. The effect occurs quickly.

The suspensions must be shaken before use. Patients should only take antacids for self-medication for about two weeks. If the symptoms persist, a medical consultation is recommended because there may be a serious cause such as a stomach or intestinal ulcer or cancer.

Active ingredientsContraindications

The contraindications depend on the composition. These include (selection):

  • Hypersensitivity
  • Renal failure
  • Hypercalcemia (calcium salts)
  • Hypermagnesaemia (magnesium salts)
  • Hypophosphataemia (aluminum salts)

The complete precautionary measures can be found in the product information sheet.


Anacids can form complexes with some active ingredients, reducing their absorption, bioavailability, and effectiveness. Typical examples are quinolones, tetracyclines, NSAIDs, salicylates, bisphosphonates and iron supplements. For this reason, there should be an interval of at least two hours between intake. Antacids are not recommended during antibiotic therapy.

Raising the gastric pH can decrease the bioavailability of other drugs, e.g. the weak bases itraconazole and ketoconazole. The time interval is also recommended here.

unwanted effects

Possible undesirable effects include a change in the consistency of the stool (diarrhea or constipation), disruption of the mineral balance and belching of carbonates due to the formation of carbon dioxide.

Disturbances of the mineral content occur mainly with kidney failure and with long-term and high-dose intake. This includes:

  • Hypermagnesaemia (magnesium)
  • Hypophosphataemia (aluminum binds phosphate)
  • Increase in serum aluminum levels, storage of aluminum in nerve and bone tissue (aluminum)
  • Hypercalcaemia (calcium)
Checklist for advising patients

Download: Checklist_Antacids.pdf

see also

Proton pump inhibitors, H2 receptor antagonists, bases

  • Medicinal product information (CH, D)
  • Ching C.K., Lam S.K. Antacids. Indications and limitations. Drugs, 1994, 47 (2), 305-17 Pubmed
  • European Pharmacopoeia PhEur
  • Maton P.N., Burton M.E. Antacids revisited: a review of their clinical pharmacology and recommended therapeutic use. Drugs, 1999, 57 (6), 855-70 Pubmed
  • Ogawa R., Echizen H. Clinically significant drug interactions with antacids: an update. Drugs, 2011, 71 (14), 1839-64 Pubmed
  • Sadowski D.C. Drug interactions with antacids. Mechanisms and clinical significance. Drug Saf, 1994, 11 (6), 395-407 Pubmed

Conflicts of Interest: None / Independent. The author has no relationships with the manufacturers and is not involved in the sale of the products mentioned.

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