Generic
Ranitidine
160 brands available in the market
At a glance
Ranitidine is an H2 receptor antagonist that reduces stomach acid production. It is used for heartburn, indigestion, peptic ulcers, gastroesophageal reflux disease (GERD), and other acid-related conditions.
Description
Ranitidine competitively blocks histamine at H2-receptors of gastric parietal cells, inhibiting gastric acid secretion. It does not affect pepsin secretion, pentagastrin-stimulated intrinsic factor secretion, or serum gastrin.
Indications
- Benign gastric and duodenal ulcers
- Hypersecretory conditions (Zollinger-Ellison syndrome)
- Gastroesophageal reflux disease (GERD)
- Erosive esophagitis
- Dyspepsia
- Prevention and treatment of NSAID-associated ulceration
Therapeutic class
H2 Receptor Antagonist
Pharmacological class
H2-Receptor Antagonist
Pharmacology
Ranitidine competitively binds to H2-receptors on gastric parietal cells, inhibiting gastric acid secretion. It reduces both basal and food-stimulated acid secretion and increases gastric pH, aiding ulcer healing and relieving acid-related symptoms.
Mechanism of action
Inhibits gastric acid secretion by blocking H2 receptors on parietal cells.
Dosage
Adult Dose (Oral):
- Gastric/duodenal ulcer: 300 mg at bedtime OR 150 mg twice daily (4-8 weeks); maintenance 150 mg at bedtime; max 300 mg twice daily
- GERD: 150 mg twice daily OR 300 mg at bedtime (up to 8 weeks); severe: 150 mg 4 times daily (12 weeks)
- Dyspepsia: 150 mg twice daily (up to 6 weeks); short-term: 75 mg as needed (max 4 doses/day, up to 2 weeks)
- Erosive esophagitis: 150 mg 4 times daily; maintenance 150 mg twice daily
- NSAID-associated ulcer: 150 mg twice daily OR 300 mg at bedtime (8-12 weeks); prevention: 150 mg twice daily
- Hypersecretory conditions: 150 mg 2-3 times daily; increase if needed; max 6 g/day
Pediatric Dose (Oral):
- Ulcer (1 month-16 years): 4-8 mg/kg/day in 2 divided doses, max 300 mg/day; maintenance 2-4 mg/kg/day (max 150 mg/day)
- GERD (1 month-16 years): 5-10 mg/kg/day in 2 divided doses, max 300 mg/day
- Erosive esophagitis: 5-10 mg/kg/day in 2 divided doses, max 600 mg/day
Administration
- May be taken with or without food; take at a fixed time
- Swallow tablet whole; do not chew, crush, or break
- Maintain 2-hour interval with antacids
Missed dose
If you miss a dose, take it as soon as you remember; skip if it's almost time for next dose; do not double the dose.
Side effects
Common Side Effects:
- Sleepiness
- Headache
- Tiredness
- Constipation
- Diarrhea
Precautions & warnings
- Does not usually affect driving ability
- Maintain 2-hour interval with antacids
- Avoid soft drinks, citrus fruits (can irritate stomach and increase acid secretion)
- Inform doctor if no improvement after 2 weeks
- Dose adjustment needed in kidney disease
Contraindications
- Porphyria
Drug interactions
- Propantheline bromide: Delayed absorption and increased peak serum concentration
- Coumarin anticoagulants, theophylline, diazepam, propranolol: Minimal hepatic metabolism inhibition
- pH-dependent drugs (ketoconazole, midazolam, glipizide): Altered absorption
- Antacids: Reduced bioavailability
Food interactions
Alcohol consumption with Ranitidine is unsafe.
Use in pregnancy
Use in Pregnancy: Generally considered safe; animal studies have shown low or no adverse effects; limited human studies.
Pregnancy Category: B — always consult a doctor before taking during pregnancy.
Use in lactation
Use in Lactation: Probably safe; limited human data suggests no significant risk.
Pediatric use
Pediatric dose based on age and weight; consult your doctor.
Geriatric use
Caution required in elderly patients; dose adjustment may be needed.
Renal / hepatic impairment
Renal Impairment: Caution in kidney disease; CrCl <50: 150 mg at bedtime; adjust dose cautiously; consult your doctor.
Hepatic Impairment: Caution in liver disease; dose adjustment may be needed; consult your doctor.
Overdose effects
No overdose information available; consult your doctor if taken in excess.
Storage conditions
Store in a cool and dry place, protected from light; keep out of reach of children.
Chemical structure
Ranitidine