Zantac ranitidine or usually used in the treatment of peptic ulcer. Dosage, adverse effects, contraindications, pharmacokinetics and presentation.

Ranitidine inhibits the production of stomach acid, which is commonly used in the treatment of peptic ulcer and gastroesophageal reflux. In general ranitidine is useful is those conditions where there is an overproduction of acid, as also happens with the Zollinger-Ellison syndrome . Its effect healing of the mucous serves to protect the gastrointestinal wall. Its action lasts for 8 to 12 hours, is partially metabolized by the liver and eventually excreted in urine and feces. Ranitidine is available without prescription and presentation can be found in the form of tablets, effervescent tablets or granules or as syrup. It is recommended to ingest in food or, failing that, along with any medications.

Dose of ranitidine

The doses to be administered ranitidine vary depending on what the condition to be treated. The administration of this drug can be orally or intravenously. Dose as the condition to be treated:

Duodenal ulcer: the doses are 150 mg. that may be taken 2 times daily or as a single dose of 300 mg. before bedtime. Maintenance prophylactic for possible recurrence is 150 mg. night.
Active benign gastric ulcer: the dose is 150 mg 2 doses. or 1 single dose of 300 mg. night.


Gastroesophageal reflux: 2 doses of 150 mg. or 1 shot of 300 mg. night. In severe cases the dose may be 600 mg. divided into 4 daily doses of 150 mg. As regards children weighing over 30 kg. the dose is 5 to 10 mg. per kg. per day divided in 2 doses, with a maximum of 600 mg. daily.
Zollinger-Ellison: be administered doses of 150 mg. 3 or 4 times a day, if necessary, may be increased to 4 doses of 300 mg. per day.
Mendelson’s syndrome : prevention is taken as 150 mg. 2 hours prior to general anesthesia.
Ranitidine may also be administered intravenously. Will be in a slow (2 minutes) at doses of 50 mg. diluted in saline, dextrose, or Hartman . The process may be repeated every 6 to 8 hours. Will resume oral administration of ranitidine as soon as the patient’s condition allows.

Alternatively continuous infusion. In this case be administered in doses of 25 mg. per hour for 2 hours, repeating the process every 6 to 8 hours. In the case of Mendelson’s syndrome, as regards the prevention and in the case of elective surgery (no emergency), were administered 50 mg. the night before and another 50 mg. with the anesthetic solution. In the case of emergency surgery should be administered 50 mg. as soon as possible.

Side effects and contraindications ranitidine

The most common adverse reactions that can result in taking ranitidine include dizziness, drowsiness, insomnia, constipation, diarrhea, vomiting, stomach pain or headache. These symptoms usually last a short time and not be serious. In the event that this does not happen we must inform your doctor immediately. In some cases you may receive mental confusion, depression, hallucinations or agitation. More rarely other symptoms may also occur, such as pancreatitis , hepatitis or elevated liver transaminases. Other reactions that disappear when stopping the medication may include arthralgia and myalgia, erythema multiforme or skin rash. Exceptionally hair loss may occur. Ranitidine is contraindicated in those patients with hypersensitivity to this drug or any of its ingredients.

Ranitidine during pregnancy and lactation

Although studies in relation to pregnancy have shown that defects in humans may arise, if known to cross the placental barrier and that in the absence of further information, we recommend its use only if deemed essential. Should be avoided especially during the first quarter. It is also known that ranitidine is excreted in breast milk so it should not be taken during breastfeeding if not essential.