Ranitidine is a histamine H2-receptor antagonist that effectively reduces stomach acid production. It is widely prescribed for the management of acid-related gastrointestinal conditions, offering symptomatic relief and promoting mucosal healing. This medication works by competitively inhibiting histamine at H2 receptors of gastric parietal cells, leading to a marked decrease in both basal and stimulated acid secretion. Its well-established efficacy and favorable safety profile have made it a cornerstone in gastroenterological therapy for decades.

Features

• Active ingredient: Ranitidine hydrochloride
• Available in oral tablet, effervescent tablet, capsule, and syrup formulations
• Standard strengths: 75 mg (over-the-counter), 150 mg, and 300 mg (prescription)
• Rapid onset of action, typically within 1–3 hours
• Duration of acid suppression: 4–12 hours depending on dosage
• Demonstrated efficacy in reducing both daytime and nocturnal acid secretion
• Compatible with most common pharmaceutical excipients

Benefits

• Provides rapid relief from heartburn, acid indigestion, and sour stomach
• Effectively treats and prevents recurrence of gastric and duodenal ulcers
• Reduces symptoms of gastroesophageal reflux disease (GERD)
• Helps manage pathological hypersecretory conditions like Zollinger-Ellison syndrome
• Prevents stress ulcers and acid aspiration syndrome in critical care settings
• Supports esophageal healing in erosive esophagitis

Common use

Ranitidine is primarily indicated for the short-term treatment of active duodenal ulcers and benign gastric ulcers. It is commonly prescribed for maintenance therapy to prevent ulcer recurrence after healing has been achieved. In gastroenterological practice, it is frequently used to manage GERD, including erosive esophagitis and symptomatic relief of heartburn. The medication is also employed in critical care medicine for stress ulcer prophylaxis in hospitalized patients. Additionally, it is used to treat pathological hypersecretory conditions and to prevent acid aspiration syndrome before anesthesia.

Dosage and direction

For active duodenal ulcer: 150 mg twice daily or 300 mg once daily at bedtime for 4–8 weeks. For maintenance of healed duodenal ulcers: 150 mg at bedtime. For GERD: 150 mg twice daily. For erosive esophagitis: 150 mg four times daily. For hypersecretory conditions: 150 mg twice daily, adjustable up to 6 g daily in divided doses. Tablets should be swallowed whole with water, with or without food. The effervescent formulations must be completely dissolved in water before consumption. Dosage adjustments are necessary in patients with renal impairment (creatinine clearance <50 mL/min).

Precautions

Patients should inform their healthcare provider of any kidney or liver disease before initiation. Regular monitoring of renal function is advised during prolonged therapy. Use with caution in patients with porphyria, as ranitidine may precipitate acute attacks. Elderly patients may require dosage adjustments due to age-related decreases in renal function. Long-term therapy may lead to vitamin B12 deficiency due to impaired absorption; periodic monitoring is recommended. Patients should avoid abrupt discontinuation after long-term use as rebound acid hypersecretion may occur.

Contraindications

Ranitidine is contraindicated in patients with known hypersensitivity to ranitidine or any component of the formulation. It should not be used in patients with acute porphyria or a history of acute porphyric attacks. The medication is contraindicated in patients with demonstrated cross-sensitivity to other H2-receptor antagonists. Use is not recommended in patients with phenylketonuria when considering effervescent formulations containing phenylalanine.

Possible side effect

Common adverse effects (≥1%) include headache, constipation, diarrhea, nausea, and abdominal discomfort. Less frequent side effects (<1%) may include dizziness, somnolence, insomnia, vertigo, and reversible mental confusion particularly in elderly or severely ill patients. Rare but serious adverse reactions include hepatotoxicity (elevated liver enzymes, hepatitis), blood dyscrasias (thrombocytopenia, leukopenia, agranulocytosis), and cardiovascular effects (bradycardia, AV block). Hypersensitivity reactions including bronchospasm, fever, rash, and eosinophilia have been reported.

Drug interaction

Ranitidine may alter the absorption of drugs requiring acidic gastric pH, including ketoconazole, itraconazole, and atazanavir—separate administration by at least 2 hours. It may increase the bioavailability of midazolam and triazolam. Ranitidine can potentiate warfarin effects through uncertain mechanisms; monitor INR regularly. Concurrent use with high-dose aspirin may increase salicylate levels. The medication may reduce the renal clearance of procainamide and n-acetylprocainamide. Antacids may decrease ranitidine absorption; administer simultaneously only if specifically indicated.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next scheduled dose. In that case, skip the missed dose and resume the regular dosing schedule. Patients should not double the dose to make up for a missed administration. For twice-daily regimens, if remembered within 4 hours of the next dose, skip the missed dose. For once-daily regimens, take within 12 hours of missed time or wait until next scheduled dose.

Overdose

Symptoms of overdose may include hypotension, tachycardia, bradycardia, and gastrointestinal disturbances. In cases of massive overdose, mental confusion, agitation, and seizures have been reported. Management is primarily supportive and symptomatic. Gastric lavage may be beneficial if performed soon after ingestion. Hemodialysis removes approximately 50% of circulating ranitidine and may be considered in severe cases. No specific antidote exists; treatment should focus on maintaining adequate renal function and supporting cardiovascular parameters.

Storage

Store at controlled room temperature (20–25°C or 68–77°F) in the original container. Protect from moisture and light. Keep the bottle tightly closed when not in use. Do not store in bathroom cabinets where humidity levels may fluctuate. Keep all medications out of reach of children and pets. Do not use beyond the expiration date printed on the packaging. For effervescent tablets, ensure the container is resealed properly after each use to maintain stability.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or medication. Never disregard professional medical advice or delay in seeking it because of something you have read in this product information. Individual responses to medication may vary based on health status, concomitant medications, and other factors.

Reviews

Clinical studies demonstrate ranitidine’s efficacy with duodenal ulcer healing rates of 70–90% after 4 weeks of therapy. Meta-analyses show superior symptom relief compared to placebo in GERD management. Long-term safety data from decades of use support its favorable risk-benefit profile. Patient-reported outcomes indicate significant improvement in quality of life measures related to acid reduction. Comparative studies position it as an effective alternative to proton pump inhibitors in certain clinical scenarios, particularly for nocturnal acid breakthrough. Post-marketing surveillance continues to confirm its established safety record with appropriate use.