Alginate / Antacid Combination Pregnancy: Compatible — commonly used first-line for heartburn in pregnancy; sodium content noted but systemic absorption negligible.

Gaviscon Advance (Alginate Preparation)

Brand names: Gaviscon Advance

Adult dose

Dose: 10mL (or 2 chewable tablets) after meals and at bedtime — maximum 4 doses per day.

Route: Oral

Frequency: After meals and at bedtime (maximum QDS)

Max: 40mL liquid or 8 tablets per day

Sodium alginate 500mg + potassium bicarbonate 267mg per 5mL. Forms a viscous raft on gastric contents, reducing acid reflux into oesophagus. Not a systemic drug — acts locally. Contains sodium (400mg/10mL) — caution in heart failure, hypertension, renal impairment.

Paediatric dose

Route: Oral

Frequency: After feeds

Max: 10mL per dose (children ≥2 years)

Infants: Infant Gaviscon sachets (different formulation — sodium alginate only) — 1 sachet per feed (breast or bottle). Children ≥2 years: 5–10mL after meals under medical supervision. Source: BNF for Children 2024.

Dose adjustments

Renal

Use with caution — contains potassium (risk of hyperkalaemia in renal failure).

Hepatic

No dose adjustment required.

Clinical pearls

Raft mechanism: alginate reacts with gastric acid to form a gel raft that floats on gastric contents — physically prevents acid reflux, not acid suppression.
Sodium content: Gaviscon Advance liquid 10mL contains 141mg sodium. Relevant in heart failure, hypertension, sodium-restricted diets.
Better than liquid antacids for post-prandial reflux — alginate raft persists longer than antacid effect.
Gaviscon Advance (adult) and Infant Gaviscon are DIFFERENT formulations — do not substitute one for the other.

Contraindications

Severe renal failure (potassium and sodium content)
Hypercalcaemia (calcium-containing antacid components in some formulations)

Side effects

Flatulence (common — CO₂ from reaction with stomach acid)
Constipation (mild)
Hyperkalaemia (rare — with high doses in renal failure)

Interactions

May impair absorption of other oral drugs if taken simultaneously — separate by 2 hours
Digoxin, tetracyclines, fluoroquinolones: reduced absorption (timing important)

Monitoring

Symptom response
Potassium (if renal impairment and regular use)

Reference: BNFc; BNF 90; NICE CG62 Dyspepsia and GORD; SPC Gaviscon Advance. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways