Proton Pump Inhibitor — Aspiration Prophylaxis Pregnancy: Compatible — substantial evidence of safety

Omeprazole (Perioperative — Aspiration Prophylaxis)

Brand names: Losec

Adult dose

Dose: Rapid sequence induction aspiration prophylaxis: 40 mg oral the night before and 40 mg morning of surgery (or IV 40 mg if unable to take orally). Ongoing: 40 mg OD.

Route: Oral or IV

Frequency: BD (aspiration prophylaxis); OD (standard use)

Max: 40 mg OD

Aims to reduce gastric acidity and volume in high-risk patients (obesity, GORD, hiatus hernia, full stomach, emergency surgery). Raising gastric pH >2.5 reduces risk of severe aspiration pneumonitis (Mendelson's syndrome).

Paediatric dose

Dose: 0.5 mg/kg

Route: Oral or IV

Frequency: OD

Max: 40 mg OD

Concentration: MUPS 10 mg dispersible; 40 mg IV vial mg/ml

Same paediatric doses as for GORD (see paediatric section)

Dose adjustments

Renal

No dose adjustment required

Hepatic

Maximum 20 mg OD in severe hepatic impairment

Paediatric weight-based calculator

Patient weight (kg)

Same paediatric doses as for GORD (see paediatric section)

Clinical pearls

RSI is the definitive protection against aspiration — omeprazole is adjunctive not a replacement
NICE NG180: omeprazole/ranitidine as premedication for patients at high risk of aspiration
Sodium citrate 0.3M 30 mL oral immediately before RSI: additional aspiration prophylaxis for obstetric RSI
IV omeprazole if patient is starved (cannot take oral)

Contraindications

Concomitant atazanavir

Side effects

Headache
GI disturbance
Hypomagnesaemia (long-term)

Interactions

Clopidogrel — pantoprazole preferred (less CYP2C19 inhibition)

Monitoring

Gastric pH (rarely directly measured)
Symptom response
Magnesium (long-term)

Reference: BNFc; BNF; NICE NG180; OAA Obstetric Anaesthesia; ASA Aspiration Guidelines. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways