Esomeprazole — NZ Medication Guide
📋 Reviewed by a Registered Pharmacist NZ — This information is for general educational purposes only and does not replace professional medical advice. Always consult your doctor or pharmacist before starting, stopping, or changing any medication.
What is Esomeprazole?
Esomeprazole is a proton pump inhibitor (PPI) used to reduce stomach acid production for gastric and oesophageal conditions. This medication is funded by Pharmac for GERD and peptic ulcer disease.
What is Esomeprazole Used For?
Esomeprazole is used for gastro-oesophageal reflux disease (GERD), peptic ulcer disease, Helicobacter pylori eradication (in combination), erosive oesophagitis, Zollinger-Ellison syndrome, and prevention of NSAID-induced gastric ulcers.
How Does Esomeprazole Work?
Esomeprazole is the S-enantiomer of omeprazole. It irreversibly inhibits the H+/K+-ATPase (proton pump) enzyme system in the parietal cells of the gastric mucosa, blocking the final step of acid production. This reduces gastric acid secretion by up to 90%, raising gastric pH substantially.
How to Take Esomeprazole
Taken orally once daily (20–40 mg), ideally 30–60 minutes before breakfast for optimal efficacy (proton pumps are most active when stimulated by food). Swallow capsules whole. If the capsule is difficult to swallow, open it and sprinkle the granules on apple sauce — do not crush granules.
Common Side Effects of Esomeprazole
- Headache
- Diarrhoea or constipation
- Nausea and flatulence
- Abdominal pain
Serious Side Effects — Seek Medical Attention
Contact your doctor or call 111 immediately if you experience any of the following:
- Hypomagnesaemia (low magnesium — with prolonged use — risk of tetany, seizures, cardiac arrhythmias)
- Hyponatraemia (low sodium — rare)
- Clostridium difficile infection (increased risk with PPIs)
- Fractures (possible modest increase in hip, wrist, and spine fractures with long-term high-dose use)
- Vitamin B12 deficiency (with long-term use — impaired absorption)
- Possible increased kidney disease risk (with prolonged use)
- Fundic gland polyps (benign — with long-term use)
Drug Interactions
Esomeprazole may interact with other medicines. Always inform your doctor and pharmacist of all medications you are taking. Key interactions include:
- Clopidogrel (esomeprazole, like omeprazole, may reduce antiplatelet effect by CYP2C19 inhibition — choose pantoprazole or rabeprazole if a PPI is needed with clopidogrel)
- Methotrexate (PPIs increase methotrexate toxicity)
- Atazanavir (reduced absorption — avoid)
- Mycophenolate (reduced levels)
New Zealand Prescribing Information
Esomeprazole (20 mg and 40 mg gastro-resistant capsules — Nexium® and generics) is funded by Pharmac. PPIs should be used at the lowest effective dose and for the shortest appropriate duration — long-term PPI use is associated with hypomagnesaemia, B12 deficiency, and increased infection risk. If taking clopidogrel, pantoprazole is the preferred PPI in NZ to avoid CYP2C19 interaction.
Frequently Asked Questions
Should I take my PPI with food or before food?
Proton pump inhibitors like esomeprazole work best when taken 30–60 minutes before your main meal — ideally breakfast. This timing ensures the PPIs are absorbed and active when the proton pumps are maximally stimulated by food, providing the greatest acid suppression.
How long should I take a PPI?
PPIs should be used at the lowest effective dose for the shortest necessary time. For acute reflux or ulcer treatment: 4–8 weeks. For maintenance in chronic GERD: regular review is needed. Indefinite PPIs should be reviewed regularly — many patients can step down to a lower dose or stop with lifestyle modifications.
⚠️ Disclaimer: This page is for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor or a qualified health provider. In New Zealand, medication availability and funding may vary — check with Pharmac or your pharmacist for current information.
Reviewed by a Registered Pharmacist NZ
References & Further Information
The following New Zealand and international resources were used to inform this page: