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1.1 Antacids

Aluminium hydroxide mixture

Co-magaldrox tablets, suspension ("Maalox"/"Mucogel")


Alginic Acid antacid powder (Infant Gaviscon sachets)

Simeticone liquid, sugar-free ("Infacol") - Endoscopy use only - see note.                        

Magnesium trisilicate mixture


1. Regular dosing with antacids can relieve dyspepsia, the pain of gastric ulcer, gastritis and reflux oesophagitis.

2. Liquid preparations act more rapidly than tablets. Antacids have a more prolonged action (up to 2-3 hours) if given about an hour after meals.

3. Aluminium hydroxide and magnesium trisilicate are the most cost-effective antacids, but at high dosage may produce constipation or diarrhoea respectively.

4. Co-magaldrox (e.g. "Maalox") has a low sodium content and is suitable for the majority of patients including those with cardiac or hepatic failure.

5. Alginic acid preparations (e.g. Peptac) are specifically indicated for the alleviation of symptoms arising from gastric reflux.  Gaviscon Advance contains less sodium but is twice the strength, so the dose is half that of Peptac: i.e. 5-10ml after meals and at bedtime. It is available for patients with severe reflux e.g. laryngopharyngeal reflux.

6. Magnesium trisilicate is cheaper than Maalox and is especially useful in the elderly who have reduced bowel frequency.

7. Simeticone is used to improve endoscopic visibility and diagnostic accuracy during colonoscopy by reducing air bubbles in the intestinal lumen.

Link to BNF section: 1.1.1 Antacids and simeticone