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Active substance: CIMETIDINE

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Zollinger-Ellison syndrome:
• 400mg with each of the three meals and 400mg at bedtime (total 1600mg daily)

CIMETIDINE 200mg, 400mg AND 800mg TABLETS
Read all of this leaflet carefully before you start taking this medicine.
• Keep this leaflet. You may need to read it again.
• If you have further questions, please ask your doctor or your pharmacist.
• This medicine has been prescribed for you. Do not pass it on to others. It may harm them,
even if their symptoms are the same as yours.
• If any side effects gets serious, or if you notice any side effect not listed in this leaflet,
please tell your doctor or pharmacist.
1. What Cimetidine is and what it is used for
2. Before you take Cimetidine
3. How to take Cimetidine
4. Possible side effects
5. How to store Cimetidine
6. Further information

The maximum recommended dose of Cimetidine is 2400mg a day.
Children over 1 year of age
The dose should be taken as instructed by your doctor. A dose of 25-30mg per kg bodyweight per day
may be given in divided doses.
Cimetidine 800mg Tablets are not usually prescribed for children.
People with severe kidney problems:
The dose may be lowered if you have severe kidney problems as you may be more sensitive to the
Overdose: if you take more of your medicine than you should
If you take an unintentional dose, it is unlikely to be harmful. If a large number of tablets are taken at
the one time, drink plenty of water and contact your doctor or nearest hospital casualty department

The name of your medicine is Cimetidine Tablets. Cimetidine belongs to a group of medicines known
as histamine H2 receptor agonists. They work by reducing the amount of acid produced by your
stomach (gastric acid). Acid plays a part in ulcer disease and the uncomfortable condition known as
heartburn. Reducing the amount of acid produced can help ulcers to heal and give relief where gastric
acid is causing discomfort.
Cimetidine Tablets are used to:
• Treat and relieve the symptoms of stomach/duodenal ulcers
• Treat and relieve Zollinger-Ellison syndrome (excessive secretion of acid by the stomach)
• Treat and relieve ulceration of the oesophagus (gullet) caused by reflux of gastric juices
• Prevent the recurrence of stomach/duodenal ulcers.
• Treat or prevent ulcers caused by medicines such as non-steroidal anti-inflammatory drugs
(NSAIDs), which are used to treat conditions such as arthritis.If you are taking this type of medicine,
your doctor may prescribe Cimetidine Tablets for you to try to keep you free of ulcers.
• Improve absorption of food and reduce fluid loss in short bowel syndrome
• Prevent acid coming up the oesophagus (gullet) before an anaesthetic
DO NOT take Cimetidine if you:
• Are pregnant or may be planning to become pregnant
• Are breast-feeding
• Have ever had an allergic reaction (for example, wheezing, runny nose, rash) after taking
Cimetidine or any of the ingredients of Cimetidine Tablets, see list of ingredients in section 6, further
Take special care with cimetidine
Before you take cimetidine tablets tell your doctor if:
• You have a kidney or liver complaint
• You have a low blood cell count
• You have lost weight recently and also have stomach ache or pain or indigestion at the same time,
particularly if you are over 40 years
• Have had a stomach/duodenal ulcer in the past, particularly if you are regularly taking
anti-inflammatories (NSAIDs) to treat arthritis. You should see your doctor regularly if this is the
If the answer is yes to any of the above, please tell your doctor.
Taking other medicines
Cimetidine Tablets may interfere with other medicines that you may be taking. If you are taking any of
the following medicines, make sure that your doctor is aware of this:
• Medicines to thin the blood (anticoagulants) e.g. warfarin
• Medicines to prevent fits (anticonvulsants) e.g. phenytoin
• Theophylline, a medicine to help breathing
• Lidocaine (to slow heart rate) by intravenous injection
• Procainamide, to treat irregular heart beats
• Medicines that cause a fall in blood cell count
• Non-steroidal anti-inflammatories (NSAIDs) e.g. Aspirin, indometacin
• Medicines to help treat anxiety, e.g. Diazepam
• Medicines to treat high blood pressure - e.g. Propranolol, Metoprolol, Diltiazem & Nifedipine
• Antidepressants such as amitriptyline
• Anti-diabetic medicines such as Glipizide, Metformin
• Medicines used to prevent rejection of an organ following a transplant, e.g. ciclosporin and
• Medicines used to treat fungal infections, e.g. Ketoconazole, itraconazole or posaconazole.
• Atazanavir - used in the treatment of HIV
• Medicines used in the treatment of cancer, e.g. carmustine, flourouracil, epirubicin or radiation
• Morphine - a powerful painkiller used to treat severe pain
You should also mention to your doctor or pharmacist any other medicines that you are taking,
including any that you can buy without prescription.
If you go into hospital or to see a doctor or dentist, tell them you are taking Cimetidine Tablets.
Pregnancy and breast-feeding
Unless you have recently discussed this with your doctor, please tell him or her if you are pregnant (or
think you may be), planning to become pregnant or are breast-feeding.
Driving and using machines
Cimetidine tablets are unlikely to affect your ability to operate machinery or to drive. When you first
start taking cimetidine, make sure your abilities are not affected before you drive or operate machinery
Important information about some of the ingredients of Cimetidine
The sodium content per tablet is:
• 200mg tablet - 500micrograms
• 400mg tablet - 1mg
• 800mg tablet - 1.5mg
This is to be taken into consideration by patients on a controlled sodium diet.
Follow your doctor’s instructions. The pharmacist’s label on your medicine should tell you how much to
take and how often. If it does not or you are not sure ask your doctor or pharmacist.
The dose of your medicine you need to take and length of treatment will depend on the type and
severity of your illness. Treatment is usually for a period of 4 to 8 weeks.
Swallow your tablets with a drink of water.
Adults and older people
Stomach/intestinal ulcer:
• 800mg daily taken as a single dose at bedtime or
• 400mg at breakfast and at bedtime or
• 200mg with each of the three meals and 400mg at bedtime (total 1000mg daily) or
• 400mg with each of the three meals and 400mg at bedtime (total 1600mg daily)
Prevention of stomach/intestinal ulcer:
• 400mg once daily at bedtime or
• 400mg at breakfast and at bedtime

Oesophageal Reflux disease:
• 400mg with each of the three meals and 400mg at bedtime (total 1600mg daily)

If you forget to take your medicine
If you forget to take a dose of your medicine at the correct time, leave out that dose completely and
take the next dose when it is due.
If you stop taking your medicine
Keep taking this medicine until your doctor tells you to stop. Do not stop taking it just because you feel
better. If you stop taking the medicine, your condition may re-occur or get worse.
Like all medicines, Cimetidine can have side effects although not everybody gets them.
Some side effects are more likely to occur than others. The possible side effects of Cimetidine are
listed below and can be divided as follows;
Very common
Very rare

affects more than 1 user in 10
affects 1 to 10 users in 100
affects 1 to 10 users in 1,000
affects 1 to 10 users in 10,000
affects less than 1 user in 10,000

STOP taking your medicine and tell your doctor immediately, or go to accident and emergency
if you experience any of the following side effects:
• An allergic reaction; signs of an allergic reaction are swelling of the lips, face and tongue; difficulty
breathing; skin rash, itching, feeling faint
• Inflammation of the pancreas (symptoms may include severe stomach pain or a change in type of
stomach pain)
• Skin and / or whites of the eyes start turning yellow, this may suggest a liver problem (Hepatitis)
• Kidney disorders (symptoms may include a change in the volume of urine passed and its colour)
• Unusual bleeding or bruising; or fever, sore throat, mouth ulcers, repeated infections or infections
that will not go away. This may be due to changes in your blood
The following are side effects you may wish to discuss with your doctor or pharmacist if they
become troublesome or they worry you.
• Dizziness
• Tiredness
• Muscle pain
• Headaches
• Diarrhoea
• Fast heart beats, palpitations
• Mild skin rash
• Depression, confusional states and hallucinations.
• Impotence in men
• Breast enlargement in men.
• Slowing of heart beat.
Very Rare
• Fever
• Hair loss
• Production of breast milk, in people not breast feeding or pregnant
• Joint pains
If any of the side effects gets serious, or if you notice any side effects not mentioned in this leaflet,
please tell your doctor or pharmacist.
NOTE: Patients taking this medicine on a long-term basis should be under regular supervision by their
Do not use your medicine after the expiry date shown on the pack.
Do not store your medicine above 25°C (room temperature). Store in a dry place and protect from
light. Store in the original package. If your tablets are supplied in a plastic pot keep the lid tightly
closed. If your doctor tells you to stop treatment, return any left over to the pharmacist. Only keep it if
the doctor tells you to.
What your medicine looks like
Cimetidine 200 mg Tablets are pale green, circular, biconvex, film-coated tablets, plain on one side
and embossed with “CIM 200”on the reverse.
Cimetidine 400mg Tablets are pale green, oblong, film-coated tablets, plain on one side and
embossed with “CIM400” on the reverse.
Cimetidine 800mg Tablets are pale green, oval film-coated tablets, plain on one side and embossed
with “CIM 800” on the reverse.
Cimetidine 200mg Tablets are available in pack sizes of 120 tablets.
Cimetidine 400mg Tablets are available in pack sizes of 60 tablets.
Cimetidine 800mg Tablets are available in pack sizes of 30 tablets.
What your medicine contains
Each 200mg Cimetidine Tablet contains 200mg of the active ingredient cimetidine.
Each 400mg Cimetidine Tablet contains 400mg of the active ingredient cimetidine.
Each 800mg Cimetidine Tablet contains 800mg of the active ingredient cimetidine.
The other ingredients are microcrystalline cellulose, polyvidone, sodium starch glycollate, sodium
lauryl sulphate, colloidal anhydrous silica, magnesium stearate, macrogol 400, hypromellose and the
colours, titanium dioxide (E171), quinoline yellow aluminium lake (E104), indigo carmine aluminium
lake (E132) and iron oxide yellow (E172).
This leaflet is a summary. It does not contain the complete information about your medicine. If you
have any further questions or are not sure about anything, ask your doctor or pharmacist who have
access to additional information.
Marketing Authorisation Holder and company responsible for release of this medicine:
Athlone Pharmaceuticals Limited, Ballymurray, Co.Roscommon, Ireland.
Distributor: Kent Pharmaceuticals Limited, Wotton Road, Ashford, Kent, TN23 6LL, U.K.
PL Numbers:
Cimetidine 200mg Tablets: PL30464/0021
Cimetidine 400mg Tablets: PL30464/0022
Cimetidine 800mg Tablets: PL30464/0023.
This leaflet was revised in January 2011.



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Source: Medicines and Healthcare Products Regulatory Agency

Disclaimer: Every effort has been made to ensure that the information provided here is accurate, up-to-date and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. This information has been compiled for use by healthcare practitioners and consumers in the United States. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate that the drug or combination is safe, effective or appropriate for any given patient. If you have questions about the substances you are taking, check with your doctor, nurse or pharmacist.