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Metformin Tablets 500mg and 850mg


What you should know about Metformin
Please read this leaflet carefully before you start to take your medicine. This leaflet provides a summary of
the information available on your medicine. If you have any questions or are not sure about anything, ask
your doctor or pharmacist.
The name of your medicine is Metformin Tablets 500mg or 850mg.
What is in your Medicine?
Each film-coated tablet contains 500mg or 850mg of the active ingredient, metformin hydrochloride. They
also contain: sodium starch glycollate, maize starch, povidone, colloidal anhydrous silica, magnesium
stearate, methylhydroxypropylcellulose, propylene glycol, polyethylene glycol, purified talc, and titanium
dioxide (E171).
Metformin Tablets are supplied in packs of 28 and 56. However, the quantity dispensed by the pharmacist
will be according to your prescription.
Metformin belongs to a group of medicines called biguanide antihyperglycaemics which help to bring down
the blood sugar levels when you have diabetes.
The product licence holder and manufacturer is: Sandoz Ltd, 37 Woolmer Way, Bordon, Hampshire,
GU35 9QE.
Metformin Tablets are commonly prescribed for patients with maturity onset-type of diabetes mellitus
(non-insulin dependent/Type II diabetes) when dietary measures are inadequate to control the diabetes,
especially if the patient is overweight, or if attempts to achieve control with sulphonylureas (an alternative
group of medicines used for diabetes) and exercise have been unsuccessful.
Metformin may also be used with sulphonylureas, in which case your doctor will closely monitor your
Before taking your medicine
DO NOT take this medicine before telling your doctor if:
• you are, or might be pregnant, or you are breast-feeding,
• you have previously experienced sensitivity to metformin, or any of the other ingredients in this medicine,
• you have had diabetic coma, ketosis, or lactic acidosis,
• you have recently had a serious infection, injury or operation,
• you are dehydrated, or you have been vomiting or have had diarrhoea recently,
• you suffer from heart disease, e.g. heart failure, or you have had a recent heart attack,
• you have chronic breathing problems, or have poor circulation,
• you have liver or kidney problems.
It is very important that you tell your doctor about any other medicines you may be taking whether they are
prescribed for you or you buy them from the pharmacy, as if taken with metformin, they may affect the
control of your diabetes. In particular let the doctor know if you are taking insulin or sulphonylurea drugs
such as glibenclamide (for your diabetes); anticoagulants such as warfarin (to prevent blood clots);
cimetidine (to treat stomach ulcers); ketotifen (for allergic conjunctivitis); ACE Inhibitors (for heart failure and
hypertension), MAOIs (antidepressants) and Octreotide (for cancer and tumour).
Avoid drinking alcohol while being treated with Metformin Tablets.
If you have to see the dentist, go to the hospital for an operation or treatment or are seen by a different
doctor for any reason, make sure that they know you have diabetes and that you are taking metformin. This
is very important if you are to be given an anaesthetic or have to stop eating and drinking for a while before
any medical tests are carried out. You will be told to stop taking Metformin Tablets 2-3 days before you are
due to have special X-ray examinations on your circulation or your kidneys. Your doctor will tell you when to
resume treatment with metformin.
The control of your blood sugar levels must be regularly monitored while taking metformin, as usual.
Your doctor may need to carry out regular blood tests whilst you are taking this medicine in order to monitor
the control of your diabetes, vitamin B 12 levels and kidney function.
Patients taking metformin alone do not usually become hypoglycaemic. However if you are also taking a
sulphonylurea, hypoglycaemia may occur; in which case the normal caution with driving or operating
machines should be observed.

Taking your medicine
Recommended doses follow. Doctors sometimes prescribe different doses to these: if this applies to you,
discuss it with your doctor, if you have not already done so. You should always follow your doctorʼs
instructions as to how and when to take your medicine. Your pharmacist may be able to advise if you are not
sure. Exactly how many tablets to take and when to take them will be written on the label. Please read it
Metformin Tablets should be swallowed whole with a drink of water, with meals.
Adults and elderly patients without kidney problems: The usual initial dose of metformin is one 500mg tablet
3 times daily, or one 850mg tablet twice daily. Control of your diabetes may occur in a few days, but can
often take up to 2 weeks. The dose may be slowly increased by your doctor, if necessary, to a maximum
dose of 3,000mg (3g) daily. Once control is obtained your doctor may decide to reduce your dosage.
Children: Metformin Tablets are not recommended for children.
You should finish all the tablets your doctor has prescribed. DO NOT stop taking your medicine, even if you
feel better, as it may be dangerous to stop taking the medicine without your doctorʼs advice.
If you forget to take a dose, take the missed dose as soon as you remember. If your next dose is due within
2 hours take a single dose now and miss the next dose. Never take two doses together. Continue with your
treatment at the correct times.
If you take one extra dose, this may unbalance the control of your diabetes especially if you are also taking
other medicines. Contact your doctor if you are worried about this. If you, or anyone else has taken an
overdose, contact your nearest hospital accident and emergency department straight away.
As with all medicines, Metformin Tablets may have unwanted effects in some patients, particularly when they
first start to take them. Stomach upsets such as nausea, diarrhoea, abdominal pain, vomiting or loss of
appetite may occur but taking your tablets with or after meals may reduce this. The effects may wear off as
treatment continues and the diabetes becomes controlled. Another common side effect is a metallic taste in
the mouth. If you suffer badly from these effects, contact your doctor who might lower your dose temporarily.
You may absorb less vitamin B12 from your diet which, if not recognised early, could result in anaemia. If
there is a tendency to bruise easily, you bleed from the gums or elsewhere, you become less resistant to
infections, or you feel very tired and look pale, see your doctor.
Your blood glucose level may become too low (hypoglycaemia) though this is less likely than with
sulphonylurea drugs for diabetes. Symptoms are sweating, weakness, hunger, dizziness, trembling,
headache, palpitations and confusion. Take sugar lumps or glucose at the first sign of these symptoms, as
you normally would for hypoglycaemia.
Occasionally, high levels of lactic acid may build up in the blood (known as lactic acidosis), which is more
likely if you have existing kidney problems. Early indicators of this may be nausea, vomiting, diarrhoea, and
lower abdominal pain which can come on suddenly or become worse. Other signs are tiredness, abnormally
fast or deep breathing, or unexplained weight loss. This is a serious condition, therefore contact your doctor
immediately if you have some or all of these symptoms.
Other unwanted effects that you may experience include anorexia (eating disorder), hepatitis (liver disease)
and skin reactions (such as itching, nettle rash, flushes and redness).
If you have any of these effects and they become worse, inconvenient or upsetting, see your doctor or
If you experience any other unpleasant effects which you think could be caused by this medicine you should
contact your doctor or pharmacist for advice.
Storing your medicine
Do not take any of the tablets after the expiry date printed on the container. Any out of date medicines
should be returned to your pharmacist for disposal.
Metformin Tablets should be stored below 25˚C in a dry place.
If you notice any defects in the tablets, such as broken or chipped tablets, take them to your pharmacist for
Date of preparation: 05/2007
Keep all medicines out of the reach and sight of children. Your medicines can harm them.
REMEMBER, this medicine is for you. Only a doctor can prescribe it for you. Never give it to others. It may
harm them even if their symptoms are the same as yours.
This leaflet applies to Metformin Tablets 500mg and 850mg only.

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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.