Magnesium carbonate

How it works

It neutralises gastric acid through an acid-base reaction, raising intragastric pH and relieving acid-related symptoms.

Prescribing in practice

• Magnesium salts can accumulate and cause toxicity in renal impairment, so use with caution and avoid in significant renal failure.
• Magnesium-based antacids tend to have a laxative effect, which is why they are often combined with constipating aluminium-containing salts.
• Antacids can reduce the absorption of various other medicines, so separate administration from interacting drugs.

Monitoring

Routine monitoring is not required for occasional use, but consider renal function in patients with impairment or those taking magnesium-containing products regularly.

Counselling the patient

• Take it for symptom relief and leave a gap between this and your other medicines.
• Tell your clinician if you have kidney problems or if indigestion is persistent or severe.

Evidence & guidelines

Antacids such as magnesium carbonate provide symptomatic relief in dyspepsia and are an established self-care option consistent with NICE guidance.