Ranitidine (Famotidine) — 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 Ranitidine (Famotidine)?
Famotidine is an H2 receptor antagonist (H2 blocker) used to reduce stomach acid, often as an alternative to proton pump inhibitors. This medication is famotidine is funded by Pharmac; ranitidine was withdrawn from the NZ market due to NDMA contamination concerns.
What is Ranitidine (Famotidine) Used For?
Famotidine is used for gastro-oesophageal reflux disease (GERD), peptic ulcer disease, heartburn, and Zollinger-Ellison syndrome. It is also used to prevent stress ulcers in hospitalised patients.
How Does Ranitidine (Famotidine) Work?
Famotidine competitively blocks H2 receptors on gastric parietal cells, reducing histamine-stimulated acid secretion. H2 blockers reduce acid secretion less completely than PPIs but are often preferred for on-demand relief and short-term management.
How to Take Ranitidine (Famotidine)
For GERD and peptic ulcers: 20–40 mg once or twice daily. Available as tablets and dispersible tablets. Take at bedtime for nocturnal acid suppression. Onset of action is faster than PPIs (within 1–2 hours); best for acute symptom relief.
Common Side Effects of Ranitidine (Famotidine)
- Headache
- Dizziness
- Diarrhoea or constipation
- Fatigue
- Dry mouth
Serious Side Effects — Seek Medical Attention
Contact your doctor or call 111 immediately if you experience any of the following:
- Confusion or mental status changes (particularly in the elderly or in renal impairment)
- QT prolongation (rare — at high doses)
- Thrombocytopenia (rare)
- Severe skin reactions (rare)
Drug Interactions
Ranitidine (Famotidine) may interact with other medicines. Always inform your doctor and pharmacist of all medications you are taking. Key interactions include:
- Ketoconazole and itraconazole (reduced absorption — separate by at least 2 hours)
- Warfarin (possible modest enhancement)
- Probenecid (increases famotidine levels)
New Zealand Prescribing Information
Famotidine (20 mg, 40 mg tablets) is funded by Pharmac as the preferred H2 receptor antagonist following the global withdrawal of ranitidine due to NDMA (N-nitrosodimethylamine) contamination concerns in 2019. Famotidine does not have the NDMA issue. It is a useful alternative to PPIs in patients who require mild to moderate acid suppression or who experience PPI side effects.
Frequently Asked Questions
Why was ranitidine (Zantac) withdrawn?
Ranitidine was withdrawn globally in 2019–2020 after detection of NDMA (N-nitrosodimethylamine), a probable carcinogen, in some ranitidine products — at levels above acceptable thresholds, particularly when stored at higher temperatures. Famotidine does not have this issue and is the recommended H2 blocker replacement in NZ.
Is famotidine as effective as a PPI for reflux?
H2 blockers like famotidine are generally less potent acid suppressors than PPIs. For mild to moderate GERD, famotidine is often sufficient. For erosive oesophagitis or severe GERD, a PPI is usually more effective. Your doctor will recommend the appropriate treatment based on your symptoms.
⚠️ 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: