Antacid medication
โ ๏ธ Important: Metal ions (Caยฒโบ, Feยณโบ) form complexes with tetracyclines, reducing absorption and bioavailability.
๐ Always check the BNF or product datasheet for the most up-to-date advice.
๐ About
- Antacids and alginates are widely used for symptom relief in acid reflux and dyspepsia.
- Always check the BNF or equivalent before prescribing or advising patients.
โ๏ธ Mode of Action
- Antacids neutralise gastric acid to reduce irritation and improve symptoms.
- Alginates form a viscous "raft" that floats on stomach contents, protecting the oesophageal mucosa from reflux.
๐ Indications & Typical Doses
- ๐ก๏ธ Acid reflux / GORD: symptomatic relief.
- Examples:
- ๐ข Aluminium hydroxide โ 1 capsule PO, QDS
- ๐ข Magnesium carbonate โ 10 mL in water PO, TDS
- ๐ข Magnesium trisilicate โ 10 mL in water PO, TDS
- ๐ข Alginate raft-forming suspensions โ 10โ20 mL PO, after meals + bedtime
- ๐ข Gastrocote โ 5โ10 mL PO, QDS
- ๐ Always check the BNF for dose ranges and prescribing updates.
๐ Interactions
- Reduced absorption of certain drugs (e.g., tetracyclines, fluoroquinolones, bisphosphonates).
โก๏ธ Separate administration by at least 2โ3 hours.
โ ๏ธ Cautions
- High sodium load can worsen hypertension, heart failure, or renal disease.
- Alginates โ viscosity of stomach contents, protecting mucosa but may cause bloating.
- โRaftโ formation reduces reflux symptoms but does not treat underlying pathology.
๐ซ Contraindications
- Severe renal impairment (risk of aluminium/magnesium accumulation).
- Hypophosphataemia (worsened by aluminium hydroxide).
๐ฅ Side Effects
- Aluminium hydroxide โ constipation, hypophosphataemia.
- Magnesium salts โ diarrhoea, belching (due to COโ release).
- General โ bloating, altered bowel habits, sodium overload.
๐ References
- BNF โ NICE
- NHS England: Dyspepsia & GORD management guidance