Contains the active ingredient metformin hydrochloride
Consumer Medicine Information
What is in this leaflet
Read this leaflet carefully before taking your medicine.
This leaflet answers some common questions about metformin. It does not contain all the available information. It does not
take the place of talking to your doctor or pharmacist.
The information in this leaflet was last updated on the date listed on the last page. More recent information on this medicine
may be available.
Ask your doctor or pharmacist:
if there is anything you do not understand in this leaflet,
if you are worried about taking your medicine, or
to obtain the most up-to-date information.
All medicines have risks and benefits. Your doctor has weighed the risks of you using this medicine against the benefits they
expect it will have for you.
Pharmaceutical companies cannot give you medical advice or an individual diagnosis.
Keep this leaflet with your medicine. You may want to read it again.
What this medicine is used for
The name of your medicine is Chemmart Metformin XR 500 or Metformin XR 1000. It contains the active ingredient metformin hydrochloride.
Metformin is used control blood glucose (sugar) in people with Type 2 diabetes mellitus, especially in those who are overweight.
It is used when diet and exercise are not enough to control high levels of blood glucose.
Metformin XR can be used alone, or in combination with other medicines for treating diabetes.
Type 2 Diabetes Mellitus
Type 2 diabetes mellitus is also called Non-Insulin Dependent Diabetes Mellitus (NIDDM) or Maturity Onset Diabetes.
Insulin is a hormone that enables body tissues to take up glucose from the blood and to use it for energy or fat storage for
People with Type 2 diabetes are unable to make enough insulin or their body does not respond properly to the insulin it does
make. This causes a build-up of glucose in the blood (hyperglycaemia), which can lead to serious medical problems.
Long-term hyperglycaemia can lead to heart disease, blindness, kidney damage, poor blood circulation and gangrene.
Signs of hyperglycaemia may include:
tiredness or lack of energy
passing large amounts of urine
Ask your doctor if you have any questions about why this medicine has been prescribed for you. Your doctor may have prescribed
this medicine for another reason.
This medicine is available only with a doctor's prescription.
How it works
Metformin belongs to a group of medicines called biguanides. It lowers high blood glucose levels by:
improving your body's sensitivity to insulin and restoring the way it normally uses glucose
reducing the amount of glucose your liver makes
delaying the amount of glucose your intestine absorbs.
There is no evidence that this medicine is addictive.
Use in children
This medicine should not be used in children since safety and effectiveness in this age group has not been established.
Before you take this medicine
When you must not take it
Do not take this medicine if:
You have any of the following:
Type 1 diabetes mellitus that is well controlled by insulin alone
Type 2 diabetes that is already well controlled by diet alone
serious complications with your diabetes or diabetic ketoacidosis (a symptom of uncontrolled diabetes, in which substances
called ketone bodies accumulate in the blood - you may notice this as an unusual fruity odour on your breath)
kidney failure or severe kidney disease
dehydration (for instance due to persistent or severe vomiting or diarrhoea)
shock from severe injury or blood loss
severe liver disease
acute alcohol intoxication, chronic alcohol dependence
certain heart or blood circulation problems, including a recent heart attack or heart failure (when the heart fails to pump
blood clots in the lungs (symptoms include coughing, shortness of breath, chest pain and a fast heart rate), severe breathing
inflammation of the pancreas (symptoms include severe upper stomach pain, often with nausea and vomiting) if associated with
severe infection or hypoxia (lack of oxygen)
a severe infection or gangrene.
You need to have major surgery or an examination such as an X-ray or a scan requiring an injection of iodinated contrast (dye).
You must stop taking metformin for a certain period of time before and after the examination or the surgery. Your doctor will
decide whether you need any other treatment for this time. It is important that you follow your doctor's instructions precisely.
You are pregnant.
Insulin is more suitable for controlling blood glucose during pregnancy. Your doctor will replace metformin with insulin while
you are pregnant.
You are breast-feeding.
Your doctor will discuss with you the options of either breast-feeding or using metformin
You have had an allergic reaction to metformin or any of the ingredients listed at the end of this leaflet.
Symptoms of an allergic reaction may include cough, shortness of breath, wheezing or difficulty breathing; swelling of the
face, lips, tongue, throat or other parts of the body, rash, itching or hives on the skin; fainting or hayfever-like symptoms
If you think you are having an allergic reaction, do not take any more of the medicine and contact your doctor immediately
or go to the Accident and Emergency department at the nearest hospital.
The expiry date (EXP) printed on the pack has passed.
The packaging is torn, shows signs of tampering or it does not look quite right.
Before you start to take it
Before you start taking this medicine, tell your doctor if:
You have allergies to:
any other medicines
any other substances, such as foods, preservatives or dyes.
You have or have had any medical conditions, especially the following:
pancreatitis (inflammation of the pancreas)
heart or blood vessel problems, including heart failure.
Before starting metformin, your doctor will ask you to have a blood test to check your kidney function.
Alcohol can affect the control of your diabetes. Drinking excessive amounts of alcohol while you are being treated with metformin
may also lead to serious side effects.
Your doctor may suggest you stop drinking or reduce the amount of alcohol you drink. You should also avoid taking other medicines
that contain alcohol.
You are planning to have any operations or radiographic procedures
Taking other medicines
Tell your doctor or pharmacist if you are taking any other medicines, including any that you get without a prescription from
a pharmacy, supermarket or health food shop.
Some medicines may interact with metformin. These include:
other medicines used to treat diabetes such as insulin, glitinides (repaglinide) and sulfonylureas (e.g. gliclazide, glibenclamide,)
iodinated contrast agents (dyes)
medicines that contain alcohol, such as cough and cold syrups
corticosteroids such as prednisolone, prednisone and cortisone
tetracosactrin, a medicine used in people with multiple sclerosis, and also in young children to treat some types of seizures
danazol, a medicine used to treat endometriosis
medicines used to treat high blood pressure and some heart conditions, such as beta-blockers (metoprolol), calcium channel
blockers (nifedipine, amlodipine) and ACE inhibitors (captopril, enalapril, fosinopril, lisinopril, perindopril, ramipril,
quinapril and trandolapril).
some medicines used to treat asthma such as salbutamol and terbutaline
diuretics, also called fluid, or water tablets, such as amiloride , bumetanide, frusemide, hydrochlorothiazide and spironolactone
chlorpromazine, a medicine used to treat schizophrenia and other mental illnesses
NSAIDs (non-steroidal anti- inflammatory drugs), medicines used to relieve pain, swelling and other symptoms of inflammation,
including arthritis such as aspirin, diclofenac, meloxicam, naproxen and piroxicam
medicines used to treat ulcers and reflux, such as cimetidine
medicines used to prevent blood clots such as warfarin
thyroid hormones, such as thyroxine.
Your doctor and pharmacist have more information on medicines to be careful with or avoid while taking metformin.
If you are taking any of these you may need a different dose or you may need to take different medicines.
Other medicines not listed above may also interact with metformin.
How to take this medicine
Follow carefully all directions given to you by your doctor or pharmacist. Their instructions may be different to the information
in this leaflet.
How much to take
Your doctor or pharmacist will tell you how much of this medicine you should take. This will depend on your condition and
whether you are taking any other medicines.
Do not stop taking your medicine or change your dosage without first checking with your doctor.
The usual starting dose is 500 mg once daily with the evening meal. Your doctor may increase the dose slowly, depending on
your blood glucose levels.
The maximum recommended dose is 2 grams once per day.
The elderly and people with kidney problems may need smaller doses.
How to take it
Swallow the tablets whole with a glass of water.
Do not break, crush or chew the tablets.
If you break, crush or chew the tablets, they will not work as well. Metformin XR are modified release tablets. This means
they have a special coating which allows the active ingredient, metformin, to be released slowly over time.
When to take it
Take your medicine everyday with the evening meal.
Taking the tablets during or with your evening meal will reduce the chance of a stomach upset.
Taking it at the same time each day will have the best effect. It will also help you remember when to take it.
How long to take it for
Continue taking your medicine for as long as your doctor tells you.
Metformin will help control diabetes but will not cure it. Most people will need to take metformin for long periods of time.
When you start treatment with metformin, it can take up to some weeks for your blood glucose levels to be properly controlled.
Make sure you have enough to last over weekends and holidays.
If you forget to take it
If it is almost time to take your next dose, skip the missed dose and take your next dose at the usual time. Otherwise take
it as soon as you remember and then go back to taking your medicine as you would normally.
Do not take a double dose to make up for missed doses.
This may increase the chance of you experiencing side effects.
If you have trouble remembering to take your medicine, ask your pharmacist for some hints to help you remember.
If you take too much (overdose)
If you think that you or anyone else may have taken too much of this medicine, immediately telephone your doctor or the Poisons
Information Centre (Tel: 13 11 26 in Australia) for advice. Alternatively go to the Accident and Emergency Department at your
Do this even if there are no signs of discomfort or poisoning. You may need urgent medical attention.
If you take too much metformin, you may feel very tired, sick, vomit, have trouble breathing and have unusual muscle pain,
stomach pain or diarrhoea. These may be early signs of a serious condition called lactic acidosis (build-up of lactic acid
in the blood).
You may also experience symptoms of hypoglycaemia (low blood glucose). This usually only happens if you take too much metformin
together with other medicines for diabetes or with alcohol.
If you do experience any signs of hypoglycaemia, raise your blood glucose quickly by eating jelly beans, sugar or honey, drinking
a non-diet soft drink or taking glucose tablets.
While you are taking this medicine
Things you must do
Tell your doctor that you are taking this medicine if:
you are about to be started on any new medicine
you are pregnant or are planning to become pregnant
you are breast-feeding or are planning to breast-feed
you are about to have any blood tests
you experience any of the following signs which may indicate a life-threatening condition called lactic acidosis:
you are going to have surgery or an anaesthetic or are going into hospital
you are going to have any radiographic procedures requiring an injection of an iodinated contrast agent (dye)
Your doctor will advise you when to stop taking metformin before you have these procedures and when to start again.
Your doctor may also do tests to make sure the medicine is working and to prevent side effects.
Go to your doctor regularly for a check-up.
Tell any other doctors, dentists and pharmacists who are treating you that you take this medicine.
Metformin does not normally cause hypoglycaemia (low blood sugar), although you may experience it while taking other medicines
for diabetes such as insulin, sulfonylureas or glitinides. Make sure that you, your friends, family and work colleagues can
recognise the symptoms of hypoglycaemia (low blood sugar) and know how to treat them.
Hypoglycaemia can occur suddenly. Initial signs may include:
weakness, trembling or shaking
lightheadedness, dizziness, headache or lack of concentration
irritability, tearfulness or crying
numbness around the lips and tongue.
If not treated promptly, these may progress to:
loss of co-ordination
fits or loss of consciousness.
If you experience any of the symptoms of hypoglycaemia, you need to raise your blood glucose immediately.
You can do this by doing one of the following:
eating 5 to 7 jelly beans
eating 3 teaspoons of sugar or honey
drinking half a can of non-diet soft drink
taking 2 to 3 concentrated glucose tablets.
Unless you are within 10 to 15 minutes of your next meal or snack, follow up with extra carbohydrates such as plain biscuits,
fruit or milk.
Taking this extra carbohydrate will prevent a second drop in your blood glucose level.
If you experience any of the signs of hyperglycaemia (high blood sugar), contact your doctor immediately.
The risk of hyperglycaemia is increased in the following situations:
illness, infection or stress
taking less Metformin XR than prescribed
taking certain other medicines
too little exercise
eating more carbohydrates than normal.
Tell your doctor if any of the following happen:
you become ill
you become dehydrated (for instance due to persistent or severe diarrhoea or recurrent vomiting)
you are injured
you have a fever
you have a serious infection such an influenza, respiratory tract infection or urinary tract infection
you are having major surgery
you are having an examination such as an X-ray or a scan requiring an injection of an iodinated contrast agent (dye).
you become pregnant.
Your blood glucose may become difficult to control at these times. You may also be more at risk of developing a serious condition
called lactic acidosis. At these times, your doctor may replace metformin with insulin.
Visit your doctor regularly for check-ups.
Your doctor may want to check your kidneys, liver, heart and blood levels while you are taking metformin.
Make sure you check your blood glucose levels regularly.
This is the best way to tell if your diabetes is being controlled properly. Your doctor or diabetes educator will show you
how and when to do this.
Carefully follow the advice of your doctor and dietician on diet, drinking alcohol and exercise.
Things you must not do
Take your medicine to treat any other condition unless your doctor or pharmacist tells you to
Give this medicine to anyone else, even if their symptoms seem similar to yours
Skip meals while taking metformin
Stop taking your medicine, or change the dosage, without first checking with your doctor.
Things to be careful of
If you have to be alert, for example when driving, be especially careful not to let your blood glucose levels fall too low.
Low blood glucose levels may slow your reaction time and affect your ability to drive or operate machinery. Drinking alcohol
can make this worse. However, metformin by itself is unlikely to affect how you drive or operate machinery.
Things to be aware of
After metformin is absorbed into your body, you may see the empty tablet shell in your faeces (bowel motions). This is normal
and does not affect the way metformin works.
Possible side effects
Tell your doctor or pharmacist as soon as possible if you do not feel well while you are taking this medicine or if you have
any questions or concerns.
Do not be alarmed by the following lists of side effects. You may not experience any of them. All medicines can have side
effects. Sometimes they are serious but most of the time they are not.
Tell your doctor or pharmacist if you notice any of the following and they worry you.
This list includes the more common side effects:
Feeling sick (nausea), being sick (vomiting)
taste disturbance, loss of appetite
skin reactions such as redness of the skin, itching or an itchy rash (urticaria).
These are generally mild side effects which disappear after the first few weeks. Taking metformin with meals can help reduce
nausea and diarrhoea.
Tell your doctor as soon as possible if you notice any of the following.
These may be serious side effects. You may need medical attention. Most of these side effects are rare.
Symptoms of liver disease such as nausea, vomiting, loss of appetite, feeling generally unwell, fever, yellowing of the skin
and eyes (jaundice) and dark coloured urine.
If you experience any of the following, stop taking your medicine and contact your doctor immediately or go to the Accident
and Emergency department at your nearest hospital.
These are very serious side effects and are usually very rare. You may need urgent medical attention or hospitalisation.
Symptoms of lactic acidosis (build-up of lactic acid in the blood):
nausea, vomiting, stomach pain
feeling weak, tired or generally unwell
unusual muscle pain
dizziness or lightheadedness
shivering, feeling extremely cold
slow heart beat.
LACTIC ACIDOSIS IS A VERY RARE BUT SERIOUS SIDE EFFECT REQUIRING URGENT MEDICAL ATTENTION OR HOSPITALISATION. ALTHOUGH RARE,
IF IT DOES OCCUR, LACTIC ACIDOSIS CAN BE FATAL. THE RISK OF LACTIC ACIDOSIS IS HIGHER IN THE ELDERLY, OR PEOPLE WITH POORLY
CONTROLLED DIABETES, PROLONGED FASTING, CERTAIN HEART CONDITIONS, SEVERE LIVER OR KIDNEY PROBLEMS OR PEOPLE WHO DRINK ALCOHOL.
Tell your doctor or pharmacist if you notice anything that is making you feel unwell. It is very important that you speak
to your doctor immediately if a side effect is severe, occurred suddenly or gets worse rapidly.
Other side effects not listed above may occur in some people.
Some side effects (e.g. reduced vitamin B12 level) can only be found when your doctor does tests from time to time to check
If you think you are having an allergic reaction to Metformin XR, do not take any more of this medicine and tell your doctor
immediately or go to the Accident and Emergency department at your nearest hospital.
Symptoms of an allergic reaction may include some or all of the following:
cough, shortness of breath, wheezing or difficulty breathing.
swelling of the face, lips, tongue, throat or other parts of the body
rash, itching or hives on the skin
Storage and disposal
Keep your medicine in its original packaging until it is time to take it.
If you take your medicine out of its original packaging it may not keep well.
Keep your medicine in a cool dry place where the temperature will stay below 25°C.
Do not store your medicine, or any other medicine, in the bathroom or near a sink. Do not leave it on a window sill or in
the car. Heat and dampness can destroy some medicines.
Keep this medicine where children cannot reach it.
A locked cupboard at least one-and-a-half metres above the ground is a good place to store medicines.
If your doctor or pharmacist tells you to stop taking this medicine or it has passed its expiry date, your pharmacist can
dispose of the remaining medicine safely.
What Chemmart Metformin XR looks like
Metformin XR 500 contains 500 mg metformin hydrochloride as modified release tablets: white to off-white capsule-shaped, unscored
tablet; engraved "APO" on one side and "XR500" on the other side.
It is available in blister packs of 120 tablets.
It is also available in bottles of 120 tablets.
Metformin XR 1000 contains 1000 mg metformin hydrochloride as modified release tablets: white to off-white capsule-shaped
biconvex tablet; engraved "MXR 1000" on one side and plain on the other side.
It is available in blister packs of 60 tablets.
It is also available in bottles of 60 tablets.
* Not all strengths, pack types and/or pack sizes may be available.
Each modified release tablet contains either 500 mg or 1000mg metformin hydrochloride as the active ingredient.
It also contains the following inactive ingredients:
colloidal anhydrous silica
This medicine is gluten-free, lactose-free, sucrose-free, tartrazine-free and free of other azo dyes.
Australian Registration Numbers
Chemmart Metformin XR 500: AUST R 197405.
Chemmart Metformin XR 1000: AUST R 218275.
Apotex Pty Ltd
16 Giffnock Avenue
Macquarie Park NSW 2113
Chemmart is a registered trademark of Symbion Pharmacy Services Pty Ltd.
This leaflet was last updated in February 2015.