Antacids

What are they

Antacids are a category of drugs that includes all those used to counteract gastric acidity and its negative effects.

The internal environment of the stomach is physiologically characterized by a certain degree of acidity, because this condition is necessary for the performance of digestion.

Some specialized cells of the gastric mucosa (parietal cells) continuously secrete hydrochloric acid, increasing their activity during meals until they reach the level of acidity (whose measure is the pH) essential for the functioning of digestive enzymes (equal to a very low pH: between 1 and 3).

In order to preserve the mucosa from this strong acidity other cells (mucipar cells) produce protective substances, which create a kind of barrier on its surface.

The activity of the various cells is regulated by a complex system of hormones and neurotransmitters: gastrin, acetylcholine and histamine stimulate parietal cells; prostaglandins E and I stimulate muciparous cells.

What are they?

Drugs active against gastric acidity are divided into three groups on the basis of their mechanism of action:

Antacids

They represent the remedy of the most immediate effect against the symptoms of gastric hyperacidity, because thanks to their chemical characteristics they neutralize acidic compounds directly in the stomach.

Antisecretories

In this group there are two types of drugs:

• proton pump inhibitors, which modify the functioning of parietal cells (e.g. omeprazole);
• H2 receptor antagonists, which prevent histamine from stimulating acid secretion (e.g. ranitidine).

Cytoprotectors

Also among these drugs there are different compounds. The most common are:

• sucralfate (complex of aluminum hydroxide and sucrose sulfate), which increases the resistance of the protective layer produced by muciparous cells and stimulates their activity;
• colloidal bismuth, which forms a protective film on the gastric mucosa;
• misoprostol (chemically similar to a prostaglandin E), which stimulates muciparous cells;
• alginates (compounds of natural origin), used in particular to block gastro-esophageal reflux because they form a gel above the contents of the stomach that prevents it from rising.

When using

Drugs against gastric acidity are indicated both to alleviate symptoms due to excess acidity (pain, burning) and to treat diseases resulting from the direct effects of acidity (gastritis, peptic ulcer, reflux esophagitis).

For the first purpose, antacids taken as needed can be useful. The other two groups of drugs have a more properly therapeutic application, if used in the presence of gastritis and ulcer, or even prophylactic, if used, for example, to prevent gastric side effects of non-steroidal anti-inflammatories (NSAIDs).

Effects

Gastric acid medications rarely have major side effects.

Keep in mind, however, is the fact that by altering the chemical environment of the stomach they are able to significantly influence the absorption of many other drugs (thus modifying their effects).