Ranitidine 💊
⚠️ Ranitidine is no longer available in the UK. All ranitidine products were recalled in 2019–2020 because of NDMA contamination. This page is kept for background and exam questions only; use a PPI, or famotidine if an H2-receptor antagonist is needed.
🧪 Always test for and eradicate Helicobacter pylori in suspected peptic ulcer disease (PUD).
Do not use H2 blockers as sole therapy if H. pylori is present.
📖 About
Always check the BNF link here.
- 💊 Ranitidine is a histamine H2-receptor antagonist.
- ✅ Once considered safe and effective for reducing gastric acid secretion, especially nocturnal acid output.
- ⚠️ Note: withdrawn in many countries due to NDMA contamination concerns, but still relevant historically and for pharmacology learning.
⚡ Mechanism of Action
- ⛔ Competitive antagonist of parietal cell H2-receptors.
- ⬇️ Reduces both basal and stimulated gastric acid secretion.
- Particularly effective at suppressing nocturnal acid production.
🩺 Indications
- Peptic ulcer disease (GU/DU).
- Gastro-oesophageal reflux disease (GORD).
- Dyspepsia (episodic or NSAID-associated).
- Prophylaxis against stress ulceration in NBM/critically ill patients (IV route).
💊 Dosing – Ranitidine (verify in BNF/datasheet)
| Indication |
Details |
| 🧪 NBM / IV use |
Ranitidine 50 mg IV TDS (in 20 mL over 2 min, q8h) |
| 🩹 Benign Gastric Ulcer |
Ranitidine 150 mg PO BD or 300 mg nocte × 4–6 weeks |
| 🔥 Episodic Dyspepsia |
Ranitidine 150 mg PO BD or 300 mg nocte × 4–6 weeks |
| 💊 NSAID-associated Gastric Ulcer |
Ranitidine 150 mg PO BD or 300 mg nocte × 8 weeks |
| ⬆️ GORD |
Ranitidine 150 mg PO BD or 300 mg nocte × 8–12 weeks |
🔄 Interactions
- See BNF – may affect absorption of drugs needing acidic pH (e.g. ketoconazole, atazanavir).
⚠️ Cautions
- 🏥 Always exclude gastric cancer before treating a gastric ulcer (ranitidine can mask symptoms/signs).
- 👵 Elderly more prone to CNS side effects (confusion, agitation).
- 💧 Use with caution in renal impairment (dose adjustment required).
🚫 Contraindications
- Known hypersensitivity to ranitidine or other H2-blockers.
- Severe renal/hepatic impairment (relative – dose adjustment required).
- ⚠️ Withdrawn/contraindicated in many countries due to NDMA impurity risk.
💥 Side Effects
- 🤢 GI upset: nausea, vomiting, diarrhoea, constipation.
- 🧠 CNS: dizziness, headache, confusion (esp. elderly/renal impairment).
- ❤️ Rare: arrhythmias (esp. rapid IV administration).
- 🫀 Rare: bradycardia, hypotension (IV use).
- 🩸 Haematological: rare neutropenia, thrombocytopenia.
- 🌡️ Rare hepatitis, elevated LFTs.
- ⚡ Usually well tolerated overall.
📑 References
- BNF: Ranitidine
- MHRA/EMA statements on ranitidine withdrawal (NDMA contamination)
