Antacids and alginates
ANTACIDS AND ALGINATES
Antacids and alginates can be used to manage symptoms of infrequent indigestion and short-term reflux.
Antacids usually contain aluminium, sodium, calcium or magnesium salts, such as magnesium or calcium carbonate. They react with the acid in the stomach, reducing acidity. They act quickly, but their effect is not long-lasting. They are most effective taken when symptoms occur or are expected (commonly after food and at bedtime), although additional doses may be required. Liquid preparations are more effective than tablets, but patients may prefer the convenience of a tablet format.12
Alginates (mucopolysaccharide) include sodium alginate and alginic acid. They form a viscous gel (a 'raft') that floats on the surface, reducing reflux symptoms.12 The strength of the raft can also vary between products. Having calcium in the alginate makes the raft stronger.13
Other alginates, in combination with antacids, work by forming a reflux barrier. This increases the viscosity of the stomach contents, helping to protect the oesophageal mucosa from reflux and neutralise stomach acid.12
NOTE: Heartburn and reflux may be experienced in pregnancy. Not all products are suitable for use in pregnancy, so check the packaging first before making recommendations. Different products contain different levels of sodium, so this should be checked for patients who are on a low-sodium diet.
DID YOU KNOW? There are 3 chemical reactions that occur when alginates are used to form a raft - transformation to alginic acid, sodium carbonate reacting to release carbon dioxide, and calcium releasing calcium ions to bind with alginic acid, strengthening the raft formation.14