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.

• Certain health problems: liver/kidney problems
• Other medicines: Benzodiazepines, theophylline/aminophylline, sildenafil, beta blockers, antiarrhythmic drugs, anticonvulsants, anticoagulant drugs, ciclosporin, tacrolimus
• 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