Shintamet, the brand of
Cimetidine, is a histamine H2-receptor antagonist.
Each tablet contains: Cimetidine ..... 400mg
1. Cimetidine competitively inhibits the action of histamine at the
histamine H2-receptor of the parietal cells and thus represents a new class
of pharmacological agents, the histamine H2-receptor antagonist.
2. Studies have shown that Cimetidine inhibits both daytime and nocturnal
basal gastric acid secretion. It also inhibits gastric acid secretion
stimulated by food, histamine, pentagastrin, caffeine and insulin.
3. Cimetidine is used in condition where inhibition of gastric acid
secretion may be beneficial; such conditions include duodenal and gastric
ulcers, esophageal reflux, selected cases of persistent dyspepsia, and
pathological hypersecretory states, such as Zollinger-Ellison Syndrome.
4. Cimetidine's ability to inhibit acid secretion also means that Cimetidine
may be used for the prophylaxis of gastrointestinal hemorrhage as a
consequence of stress ulceration and in patients at risk of acid aspiration
( Mendelson's Syndrome ) during general anesthesia.
5. Cimetidine may also be used to reduce malabsorption and fluid loss in
patients with the short bowel syndrome and to reduce the degradation of
enzyme supplements given to patients with pancreatic insufficiency.
6. Cimetidine is not an anticholinergic agent.
Treatment of duodenal and gastric ulcer, esophageal reflux disease
( including heartburn and peptic esophagitis ), selected cases of persistent
dyspepsia, and pathological hypersecretory states, such as the Zollinger-Ellison
Dosage and Administration
The total daily dose by any route should not normally exceed 2.4g. The usual
dose by mouth is 400mg twice daily ( in the morning and at bedtime ). Day-time
doses should generally be taken with meals. Other regimens are 200mg, or if
necessary 400mg, three times daily with 400mg at bedtime. In the management
of duodenal and gastric ulcer, a single daily dose of 800mg by mouth at
bedtime is recommended which should be given initially for at least 4 weeks
in the case of duodenal and for at least 6 weeks in the case of gastric
In reflux esophagitis the recommended dose is 400mg four times daily ( with
meals and at bedtime ) for 4 to 8 weeks, and in pathological hypersecretory
conditions, such as Zollinger-Ellison Syndrome, a dose of 400mg four times
daily may also be required, occasionally increased to a total of 2.4g daily.
The dosage of Cimetidine should be reduced in patients with impaired renal
function; suggested doses according to creatinine clearance are: creatinine
clearance of 0 to 15mL per minute, 200mg twice daily; creatinine clearance
of 15 to 30mL per minute, 200mg three times daily, creatinine clearance of
over 50mL per minute, normal dosage. A suggested dose of Cimetidine for
children over one year of age is 25 to 30mg per kg body weight daily by
mouth or parenterally.
Precaution(s) / Warning(s)
Before giving Cimetidine to patients with gastric ulcers, the possibility of
malignancy should be excluded since Cimetidine may mask symptoms and delay
Cimetidine should be given in
reduced dosage to patients with impaired renal function. Cimetidine has been
reported to interact with many other drugs but the full clinical
significance of some of these interactions has yet to be established since
many of the studies have involved healthy subjects given single or
subtherapeutic doses. Those interactions which are generally considered to
be of clinical importance are with Lignocaine, Phenytoin, Theophylline and
Warfarin where the blood concentrations of these drugs may be increased to
such a degree that a reduction in their dosage may be necessary. Increased
blood concentrations of some antiarrhythmics, some benzodiazepines, some
betablockers, and some vasodilators have also been reported.
Use in Pregnancy and Lactation:
Pregnancy: Although studies in humans have not been done,
risk-benefit must be considered since animal studies have shown that
Cimetidine crosses the placenta. Also, a study in rats exposed to Cimetidine
during intrauterine life and the immediate neonatal period showed a
hypoandrogenization in adult life with decreased weights of
androgen-dependent tissues and decreased concentrations of testosterone.
Lactation: Problems in humans have not been documented; however,
Cimetidine is excreted in breast milk and could possibly suppress gastric
acidity, inhibit drug metabolism, and cause central nervous system (CNS)
stimulation in the nursing infant. It has been found that very high acute
and chronic milk/plasma ratios occur with the use of Cimetidine; therefore,
the Committee on Drugs of the American Academy of Pediatrics has recommended
that Cimetidine not be taken by mothers while they are breast-feeding.
Side Effect(s) / Adverse Reaction(s)
Adverse reactions of Cimetidine are generally infrequent and are usually
reversible following a reduction of dosage or withdrawal of therapy. The
most common side effects reported are diarrhea, dizziness, tiredness, and
Contraindicated in patients known to have hypersensitivity to the product.
Symptoms and Treatment for Overdosage, and Antidote(s)
In view of apparent lack of toxicity of Cimetidine in overdosage, it is
recommended that treatment should consist of gastric lavage or
administration of syrup of ipecacuanha, provided that not more than 4 hours
have elapsed since ingestion of the drug, followed by supportive measures
and symptomatic treatment only. Forced diuresis is not recommended and,
moreover, there appears to be no evidence that it enhances the excretion of
Cimetidine from the body.
Keep in a tight container. Store at temperature below 30°C. Protect from
light and moisture.
4 years from the date of manufacture.
Plastic bottle of 500's, 1000's and 1500's(for export only).
Plastic bottle of 100's.
Blister packing of 10's x 10, 10's x 50 and 10's x 100.