Antacids are usually used to treat mild cases of dyspepsia and reflux, also known as gastro-oesophageal reflux disease (GORD). They are not recommended to manage more severe GORD, or in the management of peptic ulcers.
Dyspepsia
Antacids have an acid neutralising effect. The gastric contents of the stomach are acidic, and antacids work by neutralising the acidity or increasing the pH to make the stomach contents less acidic. 5 mL of an antacid mixture is usually effective in reducing the acidity of the gastric contents, which otherwise could cause symptoms such as heartburn.
In general, therapeutic doses of antacids are not associated with severe side effects.
Gastro-oesophageal reflux disease (GORD)
Most patients with GORD will respond well to the following treatment:
- Antacids at the prescribed doses
- Lifestyle changes
- Weight loss
- Postural measures.
Helicobacter pylori (H. pylori)
This bacterium is associated with both gastric and duodenal ulcers. After eradication of H. pylori and avoiding the use of NSAIDs for pain relief, a person should experience long-term healing of ulcers and re-infection is rare.
Reflux, with confirmed diagnosis of oesophagitis
Oesophagitis requires a significant suppression of acid secretion into the stomach. Proton pump inhibitors (PPIs) and H2 -receptor antagonists are both classes of medicines which may be effective in supressing the amount of acid secretion into the stomach and in reducing symptoms of reflux associated with oesophagitis.
There are various molecules available in the class of PPIs. This class is usually the prescription choice of doctors and is mostly recommended by pharmacists.
Proton pump inhibitors (PPIs)
This class of molecules is the most potent suppressors of gastric acid secretion. Their mechanism of action is to block the enzyme in the gastric parietal cell which is responsible for secreting acid into the stomach. It includes molecules such as omeprazole, esomeprazole, lansoprazole, pantoprazole and rabeprazole. In South Africa several products are registered with each of these molecules and they are available in various pack sizes in pharmacies.
These medicines are used for:
- Short-term management of peptic ulcer disease and GORD
- Long-term prevention of relapse of GORD
- Eradication of pylori in combination with antibiotics
- Treatment of Zollinger-Ellison syndrome
- Treatment and prevention of NSAID-associated ulcers or erosion of the gut wall.
There are also intravenous PPI formulations in this class which are used in high-risk patients, such as patients with bleeding peptic ulcers. Increasing the pH to a lesser acidic level stabilises ulcer clots and reduces the risk of bleeding again.
The various PPI molecules have comparable clinical efficacy, although there are differences in price, potential adverse effects, possible medicine interactions as well as patient preference.
Patients must not use PPIs for longer periods than what it is needed for. When using it long term a person may experience lower levels of magnesium and possible fractures. It is recommended that all patients at risk of osteoporosis who are on long-term treatment with a PPI should take vitamin D and calcium supplements.
Antacid therapy
There are various antacid products on the market. They are usually in combination and are sold mainly OTC in pharmacies.
Aluminium hydroxide, as in Neutracid, relieves dyspepsia and treats reflux oesophagitis. It also absorbs bile acids, various proteins, fluoride and phosphorus.
Many antacid preparations contain magnesium trisilicate (e.g. Neutracid) or other magnesium salts and are effective in the relief of dyspepsia and treatment of reflux oesophagitis.
When used alone, aluminium could cause constipation and magnesium tends to be a laxative.
It is found that many antacid products on the market contain a mixture of the antacids aluminium and magnesium compounds, which do not affect normal bowel movements as would their single components.
Antacids with antiflatulents
These mixtures are generally antacids which contain an additional substance with antiflatulent properties. Examples of these include silicones, dimeticone and simeticone.
Dimeticone
- Not systemically absorbed
- It is used to reduce flatulence and dyspepsia
- In infants it may occasionally be of benefit in colic.
Simeticone
It is a mixture of liquid dimeticone together with silicon dioxide.
Antacids with antispasmodics
Dicyclomine is indicated as an antispasmodic, which is a medicine that relieves or prevents bowel spasms. It is not recommended to combine it in one preparation; rather use antacids and antispasmodic medicines separately than in a single-component product. This is based on the precautions, contraindications and adverse effects of dicyclomine.
External References:
- South African Medicines Formulary. 13th 2020. Pages 38 – 41.
