Co-magaldrox (Aluminium and Magnesium Hydroxide)

How it works

The constituent hydroxides neutralise gastric acid, raising intragastric pH; pairing aluminium and magnesium salts balances their opposing effects on bowel transit.

Prescribing in practice

• Use with caution in renal impairment, where aluminium and magnesium can accumulate and cause toxicity, and avoid in hypophosphataemia.
• Separate dosing from other oral medicines because antacids reduce the absorption of many drugs, including certain antibiotics, bisphosphonates and iron.
• Be aware the preparation contains sodium and may cause altered bowel habit, with magnesium tending to loosen and aluminium to constipate.

Monitoring

Routine monitoring is not generally required for short-term use, but consider renal function and electrolytes in patients with renal impairment or prolonged use.

Counselling the patient

• Take after meals and at bedtime, or when symptoms occur.
• Leave a gap between this and your other medicines.
• See a doctor if symptoms persist or worsen.

Evidence & guidelines

Antacid efficacy for symptomatic acid-related dyspepsia is well established and reflected in current prescribing references and the SPC.