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Proton Pump Inhibitor Pregnancy: C

Omeprazole (Elderly)

Brand names: Losec, Prilosec

Adult dose

Dose: 20–40 mg once daily (treatment); 10–20 mg once daily (maintenance); 20 mg once daily (prevention of NSAID ulcers)
Route: oral or IV
Frequency: once daily
Max: 40 mg/day (oral); 40 mg/day (IV) for Zollinger-Ellison up to 120 mg/day
Take 30–60 min before food for best effect; in elderly: review indication regularly — long-term use without clear indication very common

Paediatric dose

Dose: 0.7 mg/kg
Route: oral
Frequency: once daily
Max: 40 mg/day
Concentration: 10 mg/mL suspension mg/ml
GORD: ≥1 year: 0.7–1.4 mg/kg/day; 1–2 years: 5–10 mg/day; >20 kg: 20 mg/day; H. pylori eradication: 1–2 mg/kg/day

Dose adjustments

Renal

No dose adjustment required

Hepatic

Reduce dose in severe hepatic impairment; max 20 mg/day

Paediatric weight-based calculator

GORD: ≥1 year: 0.7–1.4 mg/kg/day; 1–2 years: 5–10 mg/day; >20 kg: 20 mg/day; H. pylori eradication: 1–2 mg/kg/day

Clinical pearls

  • SIGN/NICE: review PPI indication every 6–12 months — >50% of long-term prescriptions in elderly may lack clear indication
  • Step-down therapy: H2 antagonist or on-demand PPI for maintenance after healing — reduces long-term risks
  • Hypomagnesaemia: check magnesium if on long-term PPI + diuretics/digoxin/QT-prolonging drugs

Contraindications

  • Concurrent atazanavir/nelfinavir (pH-dependent absorption)

Side effects

  • Headache
  • Diarrhoea
  • Nausea
  • Hypomagnesaemia (long-term)
  • Hyponatraemia
  • C. difficile (long-term)
  • Osteoporosis/fractures (long-term high-dose)
  • B12 deficiency (long-term)

Interactions

  • Clopidogrel (CYP2C19 — use pantoprazole instead)
  • Methotrexate (increases levels)
  • Warfarin (increased INR — weak)
  • Atazanavir (reduced absorption — CI)

Monitoring

  • Magnesium (long-term use)
  • B12 (if long-term use >3 years)
  • Bone density (if osteoporosis risk)

Reference: BNFc; BNF 86; NICE NG1; SIGN 142. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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