Ranitidine

Ranitidine is a histamine H2-receptor antagonist that effectively reduces stomach acid production, providing relief from a range of acid-related gastrointestinal conditions. As a well-established medication with a robust clinical history, it offers a reliable therapeutic option for both acute symptom management and maintenance therapy. Its mechanism of action selectively blocks histamine receptors on parietal cells, leading to a significant decrease in gastric acid secretion. This makes it a cornerstone in the management of disorders where acid suppression is clinically indicated.

Features

• Active ingredient: Ranitidine hydrochloride
• Available in oral tablet, effervescent tablet, and syrup formulations
• Standard strengths include 75 mg, 150 mg, and 300 mg
• Rapid onset of action, typically within 1–2 hours
• Duration of acid suppression: up to 12 hours per dose
• Compatible with once-daily or twice-daily dosing regimens
• Generally well-tolerated with a favorable safety profile
• Available as both prescription and over-the-counter formulations

Benefits

• Provides rapid relief from heartburn, acid indigestion, and sour stomach
• Effectively reduces nocturnal acid breakthrough
• Promotes healing of erosive esophagitis and duodenal ulcers
• Decreases recurrence rates of gastrointestinal ulcers
• Allows for comfortable consumption of trigger foods when used prophylactically
• Supports maintenance of esophageal mucosal integrity

Common use

Ranitidine is primarily indicated for the short-term treatment and maintenance therapy of active duodenal ulcers. It is also prescribed for the treatment of pathological hypersecretory conditions such as Zollinger-Ellison syndrome. Additionally, it is commonly used for the management of gastroesophageal reflux disease (GERD), including erosive esophagitis. Many patients utilize over-the-counter formulations for the relief of occasional heartburn, acid indigestion, and sour stomach. Medical professionals may also recommend it for stress ulcer prophylaxis in hospitalized patients.

Dosage and direction

For active duodenal ulcer treatment: 150 mg twice daily or 300 mg once daily for 4–8 weeks. For maintenance therapy: 150 mg at bedtime. GERD management: 150 mg twice daily. Pathological hypersecretory conditions: 150 mg twice daily, adjustable up to 6 g daily in divided doses. Over-the-counter use for heartburn: 75 mg 30–60 minutes before eating food or drinking beverages that cause heartburn, not to exceed 150 mg in 24 hours. Tablets should be swallowed whole with water; effervescent tablets must be completely dissolved in water before consumption. Dosage adjustments are necessary for patients with renal impairment.

Precautions

Patients with phenylketonuria should avoid formulations containing aspartame. Use with caution in patients with hepatic impairment, as ranitidine is metabolized in the liver. Elderly patients may require dosage adjustments due to decreased renal function. Long-term therapy may lead to vitamin B12 deficiency due to reduced acid-mediated absorption. Periodic monitoring of gastric pH may be necessary in critically ill patients. Patients should be advised that ranitidine may mask symptoms of gastric malignancy. Discontinuation may cause rebound acid hypersecretion.

Contraindications

Known hypersensitivity to ranitidine or any component of the formulation. History of acute porphyria. Concurrent use with certain HIV medications including atazanavir and delavirdine. Patients with demonstrated cross-sensitivity to other H2-receptor antagonists. Severe renal impairment without appropriate dosage adjustment. History of ranitidine-associated thrombocytopenia. Concomitant use with high-dose aspirin in patients with bleeding disorders.

Possible side effects

Common: headache (approximately 3% of patients), constipation, diarrhea, nausea. Less frequent: dizziness, somnolence, insomnia. Rare but serious: hepatitis, pancreatitis, blood dyscrasias including thrombocytopenia and agranulocytosis. Cardiovascular effects: bradycardia, atrioventricular block. Neuropsychiatric: confusion (particularly in elderly patients), depression, hallucinations. Dermatological: rash, alopecia. Musculoskeletal: arthralgia, myalgia. Endocrine: gynecomastia, impotence (with long-term high-dose therapy).

Drug interaction

Ranitidine may decrease the absorption of drugs requiring acidic gastric environment for absorption, including ketoconazole, itraconazole, and iron salts. It may alter the metabolism of warfarin, phenytoin, and theophylline through weak cytochrome P450 inhibition. Concomitant use with antacids may decrease ranitidine absorption (separate administration by at least 1 hour). May increase bioavailability of triazolam and midazolam. Potentiates effects of alcohol on gastric mucosa. Concurrent use with procainamide may increase procainamide levels. May alter pH-dependent release of enteric-coated medications.

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, the missed dose should be skipped and the regular dosing schedule resumed. 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, if remembered within 8 hours of the next dose, skip the missed dose. Consistency in dosing is important for maintaining therapeutic acid suppression.

Overdose

Symptoms of overdose may include hypotension, tachycardia, blurred vision, and exaggerated side effects. Gastric lavage may be indicated if presented within 1 hour of ingestion. Supportive measures include intravenous fluids for hypotension and symptomatic treatment. Hemodialysis may be effective due to ranitidine’s relatively low molecular weight and moderate protein binding. No specific antidote exists. Case reports indicate survival after ingestion of up to 18 grams with appropriate supportive care. Patients should seek immediate medical attention if overdose is suspected.

Storage

Store at room temperature (15–30°C or 59–86°F) in a dry place protected from light and moisture. Keep blister packs in original packaging until use. Do not transfer effervescent tablets or syrup to other containers. Protect from freezing. Keep out of reach of children and pets. Do not use if the product shows signs of discoloration, deterioration, or if the expiration date has passed. Proper disposal of unused medication through take-back programs is recommended to prevent environmental contamination.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Ranitidine should be used only under the supervision of a qualified healthcare professional. Individual response to medication may vary, and proper diagnosis should precede treatment. Patients should consult their physician before starting, changing, or stopping any medication. The manufacturer’s prescribing information should be consulted for complete details. In 2020, the FDA requested removal of all ranitidine products from the market due to concerns about NDMA impurity, and alternative acid-reducing medications should be considered.

Reviews

Clinical studies demonstrate ranitidine’s efficacy in healing duodenal ulcers in 70–80% of patients 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 generally favorable risk-benefit profile when used appropriately. Patient reports frequently note effective relief of nighttime heartburn symptoms. Some users report decreased effectiveness with prolonged use, possibly due to tachyphylaxis. Medical literature documents rare but serious adverse events including cases of hepatitis and blood dyscrasias. Comparative studies indicate slightly less potent acid suppression than proton pump inhibitors but with faster onset of action.