Drug information of Ranitidine


Drug group:

Ranitidine is in a group of drugs called histamine-2 blockers. Ranitidine works by reducing the amount of acid your stomach produces. Ranitidine is used to treat and prevent ulcers in the stomach and intestines. It also treats conditions in which the stomach produces too much acid, such as Zollinger-Ellison syndrome. Ranitidine also treats gastroesophageal reflux disease (GERD) and other conditions in which acid backs up from the stomach into the esophagus, causing heartburn

Mechanism of effect

The H2 antagonists are competitive inhibitors of histamine at the parietal cell H2 receptor. They suppress the normal secretion of acid by parietal cells and the meal-stimulated secretion of acid.


Ranitidine is a histamine H2-receptor antagonist similar to cimetidine and famotidine.


Approximately 50% bioavailability orally. Protein binding:15% Metabolism:Hepatic The principal route of excretion is the urine Half life:2.8-3.1 hours


Usual Adult Dose for Erosive Esophagitis
Initial: 150 mg 4 times a day.
Maintenance: 150 mg twice daily.
Parenteral: 50 mg, IV or IM, every 6 to 8 hours. Alternatively, a continuous IV infusion may be administered at a rate of 6.25 mg/hour over 24 hours.
Usual Adult Dose for Gastroesophageal Reflux Disease
Oral: 150 mg twice daily.
Parenteral: 50 mg, IV or IM, every 6 to 8 hours.
Usual Pediatric Dose for Gastric Ulcer
1 month to 16 years:
IV: 2 to 4 mg/kg/day divided every 6 to 8 hours
Maximum: 200 mg/day IV
Treatment: 4 to 8 mg/kg twice daily, every 12 hours
Maximum: 300 mg/day orally
Maintenance: 2 to 4 mg/kg/day orally once daily
Maximum: 150 mg/day orally

Side effects

nausea , abdominal pain , vomiting


1-Caution should be exercised when administering ranitidine to patients with hepatic dysfunction
2-Elevations in SGPT have been reported with the administration of intravenous H2 antagonists, for 5 days or longer, at doses larger than recommended.

Points of recommendation

Avoid alcohol.
Avoid excessive quantities of coffee or tea (Caffeine).
Avoid milk, calcium containing dairy products, iron, antacids, or aluminum salts 2 hours before or 6 hours after using antacids while on this medication.
Take without regard to meals.

Pregnancy level


Related drugs

Cimetidine , Famotidin , Nizatidine

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