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Drug Information
Pharmacokinetics
| Indication
& Dosage | Action
| Interacations
Precautions
|
Brands available in Market
Pharmacokinetics.
It is well absorbed orally, but its bioavailablity is
reduced when given with antacids. Theraupetic effect lasts for about 4-7
hours. It is excreted mainly in the urine, within 24 hours mainly as
unchanged drug. It can cross the placental barrier and is secreted in
milk.
Indication
& Dosage
Oral
DUODENAL ULCER: 150mg b.i.d or 300mg once daily. After 4-8 wks 150mg at
bedtime.
BENIGN GASTRIC ULCER: As for duodenal ulcer.
REFLUX OESOPHAGITIS: 150mg b.i.d for upto 8 weeks.
ZOLLINGER-ELLISON SYNDROME: 150mg 2 or 3 times daily increasing upto max
of 6g/day.
PREVENTION OF RECURRENT BLEEDING IN STRESS ULCERS: 150mg b.i.d.
PREVENTION OF ACID ASPIRATION DURING GENERAL ANAESTHESIA: 150mg orally 2
hrs before induction. May be repeated every 6 hrs as required Children:
50-150mg daily have been given.
IV, IM
PATHOLOGICAL HYPERSECRETORY CONDITIONS AND INTRACTABLE ULCERS IN
HOSPITALISED PATIENTS: 50-100mg every 6hrs.
Note: renal impairment: when creatinine clearance is less than 50ml/min
150mg every 24hrs.
Action
Block histamine H2 receptors in the stomach and prevents
histamine-mediated gastric acid secretion. It has no anticholinergic
action. Acid secretion in response to petagastrin, bethanechol and food
is also inhibited.
Aminophylline, Anticoagulants, Caffeine, Metoprolol,
Oxtriphylline, Phenytoin, Propranolol, Theophylline, Tricyclic
antidepressants (amitriptyline, amoxapine, clomipramine, desipramine,
doxepin, imipramine, nortriptyline, protriptyline ) : these drugs when
used with ranitidine have been shown to potentiate the effects of
ranitidine. Itraconazole, Ketoconazole : H2-blockers may decrease the
effects of itraconazole or ketoconazole, hence H2-blockers should be
taken at least 2 hours after these drugs.
Adverse Effect & Precautions
Dizziness, confusion, constipation,
skin rash, headache, leucopenia and thrombocytopenia.
Allergies : Allergies to Ranitidine may occur.
Pregnancy : H2-blockers have not yet been fully studied in pregnant
women. Breast-feeding : Ranitidine passes into the breast milk and may
cause adverse effects, such as decreased amount of stomach acid and
increased excitement, in the nursing baby. . Adults : Confusion and
dizziness may be especially likely to occur in elderly patients, who are
usually more sensitive than younger patients.
Pregnancy: Safety Not established
Breast Feeding: Use with caution
Man: May be used.
