🧪 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⚠️ Note: withdrawn in many countries due to NDMA contamination concerns, but still relevant historically and for pharmacology learning.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⚠️ Withdrawn/contraindicated in many countries due to NDMA impurity risk.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)

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Ranitidine 💊