The main active ingredient of the gastrointestinal medication is Ranitidine, it competitively inhibits the binding of histamine to gastric parietal cell receptors (called H2 receptors) by reducing basal and food-stimulated acid secretion, caffeine, insulin, or pentagastrin. Ranitidine reduces the volume of acid excreted in response to stimuli thereby indirectly reducing pepsin secretion. Ranitidine has no effect on gastrin, nor does it affect emptying, gastric motility, intraesophageal pressure, peristalsis, or bile and pancreatic secretions. It also has no anticholinergic properties. Ranitidine shows a healing effect on the gastrointestinal mucosa, protecting it from the irritating action of acetylsalicylic acid and other non-steroidal anti-inflammatory drugs.
Follow the exact instructions for the administration of this medicine indicated by your doctor. If in doubt, consult your doctor again.
Active duodenal ulcer
The recommended dose is one Zantac 150 mg tablet twice a day (one in the morning and one in the evening) without the need to adjust the intake of the tablets to meals. You can also take two Zantac 150 mg tablets in the evening.
These guidelines will generally be maintained for 4 to 6 weeks, even if symptom relief has been achieved in less time.
In patients with recurrent ulcers, maintenance treatment with one Zantac 150 mg tablet at night is recommended.
Benign active gastric ulcer
The recommended dose is one Zantac 150 mg tablet twice a day (one in the morning and one in the evening) without the need to adjust the intake of the tablets to meals. You can also take two Zantac 150 mg tablets in the evening.
These guidelines will generally be maintained for 6 weeks.
Reflux esophagitis
The recommended dose is one Zantac 150 mg tablet twice a day (one in the morning and one in the evening) without the need to adjust the intake of the tablets to meals. You can also take two Zantac 150 mg tablets in the evening.
These guidelines will generally be maintained for 6-8 weeks, and if necessary for up to 12 weeks.
If you have moderate to severe esophagitis, you can take up to four Zantac 150 mg tablets for up to 12 weeks.
To treat associated symptoms, take one Zantac 150 mg tablet twice daily for 2 weeks. If the initial response is not as expected, you can continue taking this same regimen for another 2 weeks.
Zollinger-Ellison syndrome.
The initial dose is one Zantac 150 mg tablet, three times a day, increasing it if necessary. Patients with this syndrome have received doses up to a maximum of 6 grams/day.
Prevention of Mendelson's syndrome (acid aspiration syndrome).
An oral dose of one Zantac 150 mg tablet will be administered two hours before general anesthesia, and preferably another 150 mg dose the previous evening.
Prevention of gastrointestinal bleeding due to stress ulcers in seriously ill patients and recurrent bleeding in patients with bleeding ulcers.
Intravenous administration should be replaced by oral administration as soon as the patient's conditions allow. The oral dose is 150 mg, twice a day.
The recommended dose is the same dose used in adults.
Children from 3 to 11 years old and weighing more than 30 kg.
This medicine is not suitable for administration in children between 3 and 11 years old because the tablets cannot be divided to adapt the dose to their weight.
Like all medicines, this medicine can cause side effects, although not everybody gets them.
Uncommon (may affect less than 1 in 100 people):
- stomach pain, constipation, feeling sick (nausea). These symptoms generally improve with continued treatment.
Rare (may affect up to 1 in 1,000 people):
Hypersensitivity reactions that have been reported after administration of a single dose of ranitidine:
- difficulty breathing, wheezing, and chest pain or tightness
- swelling of the eyelids, face, lips, mouth, or tongue (angioedema)
- skin rash or "hives" (lumps) anywhere on the body
- unexplained fever
- drop in blood pressure (hypotension)
Other rare side effects:
- transient and reversible changes in liver function tests may occur
- Rash on the skin
Very Rare (may affect up to 1 in 10,000 people):
- transient mental confusion, depression, and hallucinations, especially in seriously ill patients, the elderly, and patients with kidney problems
- inflammation of the liver (hepatitis), which can cause one or more of the following symptoms: nausea (feeling dizzy), vomiting, loss of appetite, malaise, fever, itching, yellowing of the skin or whites of the eyes usually reversible (jaundice) and dark-coloured urine
- inflammation of the blood vessels (vasculitis)
- dizziness
- reversible blurred vision
- occasionally severe skin rash (red/purple spots)
- loss of hair
- reversible impotence
- inflammation of the pancreas (pancreatitis)
- diarrhea
- headache (sometimes severe)
- low levels of white cells (leukopenia) and platelets that are cells that promote blood clotting (thrombocytopenia). These are normally reversible
- agranulocytosis (decreased number of granulocytes) and pancytopenia (decreased white blood cells, red blood cells, and platelets), sometimes accompanied by incomplete or defective bone marrow development (hypoplasia or bone marrow aplasia), which may manifest as gasping and fatigue, recurrent infections, and/or cardinals
- muscle or joint pain
- kidney problems (symptoms may include changes in the amount and color of urine, nausea, vomiting, confusion, fever, and a skin rash)
- abnormal body muscle movements or tremors
- swelling, discharge and/or discomfort in the breasts
- sudden and severe allergic reaction (reaction reported after administration of a single dose of ranitidine)
- slowed heart rate (bradycardia), accelerated heart rate (tachycardia, and heart block.
