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Cimetidine
Please note: these are basic guidelines, refer to your doctor for a professional medical opinion.
Popular brand names:
Adco-cimetidine, Lenamet
Drug group:
Anti-ulcer drug
Prescription needed?
Yes (some preparations)
What does it do?
Cimetidine promotes the healing of ulcers in the stomach and duodenum
It is used in the treatment of reflux oesophagitis (inflammation of the oesophagus due to regular exposure of the lining to stomach acid)
How does it work?
Cimetidine is an H-2 receptor antagonist
It reduces the secretion of gastric acid and pepsin in the stomach
How should it be used?
Treatment is usually given for 4-8 weeks, with further short courses if symptoms recur
Cimetidine promotes healing of the stomach lining and may mask the symptoms of stomach cancer and delay diagnosis - you may need investigation if symptoms change or persist
What is the typical dosage?
Your doctor will recommend a dosage tailored to your need, but typically:
Tablets/liquid/injection: taken 1–4 x daily (after meals and at bedtime)
Adult dose 800–1,600mg daily (occasionally increased to 2,400mg daily)
How quickly will it start to work?
Within 90 minutes
How long will the effects last?
2–6 hours
When should I stop using it?
If prescribed by your doctor, do not stop without discussing.
Is it safe for prolonged use?
Courses of longer than 8 weeks are not usually necessary.
What are the possible side effects?
Side effects are uncommon and usually disappear when the drug is stopped.
The following have been reported:
Less common:diarrhoea, dizziness, tiredness, muscle/joint pain, breast enlargement and erectile dysfunction in men
Report to your doctor before taking your next dose if you experience:confusion, hallucinations
What other considerations are important?
Dosage may be adjusted by your doctor under certain conditions.
Pregnancy and breast-feeding: Safety in pregnancy not established, side effects on the breastfed baby unlikely at normal doses
Children: Reduced dose necessary
Over 60: higher risk than other age groups of confusion and depression, as well as stomach cancer (important to exclude this before starting treatment)
Driving and hazardous work: Caution, may cause dizziness and confusion
Alcohol: Avoid as alcohol may aggravate the underlying condition