Ranitidine
Rx
Therapeutic ClassH₂ Receptor Antagonist
Common Dose150 mg / 300 mg
Max / 24h300 mg
PregnancyCategory B
Indications ▼
Duodenal ulcer (acute and maintenance)
Benign gastric ulcer
Gastroesophageal reflux disease (GERD)
Zollinger–Ellison syndrome
Stress ulcer prophylaxis
Mechanism & Pharmacokinetics ▼
Mechanism: Selectively blocks histamine H₂ receptors on gastric parietal cells, reducing basal and stimulated gastric acid secretion.
Pharmacokinetics: Oral bioavailability approximately 50%. Peak plasma concentration occurs within 1–3 hours. Minimal hepatic metabolism. Elimination half-life 2–3 hours. Primarily excreted via kidneys.
Dosage & Administration ▼
| Indication | Recommended Dose | Duration |
|---|---|---|
| Duodenal ulcer | 150 mg twice daily or 300 mg at night | 4–8 weeks |
| GERD | 150 mg twice daily | 8–12 weeks |
| Zollinger–Ellison syndrome | 150 mg three times daily | Specialist guided |
Side Effects ▼
Common: Headache, constipation, diarrhea
CNS: Dizziness, confusion (elderly)
Cardiac: Rare bradycardia (IV use)
Rare: Hepatitis, blood dyscrasias
Contraindications ▼
Hypersensitivity to ranitidine
Acute porphyria
Drug Interaction ▼
May reduce absorption of ketoconazole and itraconazole
Minimal CYP450 inhibition compared to cimetidine
Antacids may reduce absorption if taken together
Pregnancy & Lactation ▼
Pregnancy Category B
Considered relatively safe during pregnancy
Excreted into breast milk; caution advised
Patient Counseling Points ▼
Take regularly for full therapeutic benefit
Avoid smoking, alcohol and NSAIDs
Do not exceed prescribed dose
Seek medical advice if symptoms persist
Storage & Handling ▼
Store below 30°C
Protect from moisture and direct sunlight
Keep away from children
Brand Names (Bangladesh & Global) ▼
Bangladesh (Local Brands):
Global / International Brands:
Medical Disclaimer: This information is intended for educational purposes only and should not replace professional medical advice.
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