Glucophage (metformin hydrochloride)
What Glucophage is used for
Glucophage is used to control blood glucose (the amount of sugar in the blood) in people with diabetes mellitus.
Glucophage can be used in:
- type 1 diabetes, also called insulin dependent diabetes or juvenile onset diabetes, when insulin alone is not enough to control blood glucose levels
- type 2 diabetes, also called non-insulin dependent diabetes mellitus (NIDDM) or maturity onset diabetes. It is especially useful in those who are overweight, when diet and exercise are not enough to lower high blood glucose levels (hyperglycaemia).
Glucophage can be used alone, or in combination with other medicines for treating diabetes. Ask your doctor if you have any questions about why Glucophage has been prescribed for you. Your doctor may have prescribed Glucophage for another reason.
How Glucophage works
Glucophage belongs to a group of medicines called biguanides. Glucophage lowers high blood glucose (hyperglycaemia) by helping your body make better use of the insulin produced by your pancreas. 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, which can lead to serious medical problems.
Before you take Glucophage
Do not take Glucophage if you are allergic to medicines containing metformin (e.g. Diabex, Diaformin) or any other biguanide. Some of the symptoms of an allergic reaction may include skin rash, itching or hives; swelling of the face, lips or tongue which may cause difficulty in swallowing or breathing; wheezing or shortness of breath.
Do not take Glucophage if you have any of the following conditions:
Before you start to take it
- type 1 diabetes mellitus that is well controlled by insulin alone
- type 2 diabetes that is already well controlled by diet alone
- diabetic ketoacidosis (a symptom of uncontrolled diabetes, in which substances called ketone bodies build up in the blood - you may notice this as an unusual fruity odour on your breath, difficulty breathing, confusion and frequent urination)
- severe liver disease
- excessive alcohol intake
- kidney failure or severe kidney disease
- dehydration, severe blood loss
- a severe infection
- certain heart or blood vessel problems, including a recent heart attack or severe heart failure
- severe breathing difficulties
- blood clots in the lungs (symptoms include coughing, shortness of breath, chest pain and a fast heart rate)
- inflammation of the pancreas (pancreatitis)
- if you plan to have any X-ray procedures requiring an injection of iodinated contrast (dye)
- if you are pregnant or plan to become pregnant or you are breastfeeding
Tell your doctor if you have any medical conditions, especially the following:
Taking other medicines
- heart failure
- kidney problems
Tell your doctor if you are taking any other medicines, including any that you buy without a prescription from a pharmacy, supermarket or health food shop. Some medicines may be affected by Glucophage or may affect how well it works. These include:
How much to take
- sulfonylureas, a group of medicines used to treat diabetes, such as gliclazide (e.g. Diamicron, Glyade), glipizide (Minidiab, Melizide), glimepiride (Amaryl, Dimirel)
- repaglinide (Novonorm), another type of medicine used to treat diabetes
- some medicines used to treat high blood pressure and some heart conditions, including beta-blockers, calcium channel blockers and ACE inhibitors
- medicines used to prevent blood clots, such as warfarin
- thiazide diuretics, also called fluid tablets, such as hydrochlorothiazide (Dithiazide)
- thyroid preparations such as thyroxine (e.g. Oroxine)
- cimetidine (e.g. Magicul, Tagamet), a medicine used to treat reflux and ulcers
- corticosteroids such as prednisone (Panafcort, Sone), cortisone (Cortate)
The dose varies from person to person. Your doctor will decide the right dose for you.
The usual starting dose for adults is 500 mg one to two times a day. Your doctor may increase or decrease the dose, depending on your blood glucose levels. The maximum recommended dose is 1000 mg three times a day.
The elderly and people with kidney problems may need smaller doses. If your child has diabetes that is resistant to insulin and is being treated in hospital, your child's doctor will decide the dose.
How to take Glucophage
Swallow the tablets with a glass of water.
When to take Glucophage
Take Glucophage during or immediately after food. This will reduce the chance of a stomach upset. Take your medicine at about the same time each day. 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 Glucophage for
Keep taking Glucophage for as long as your doctor recommends. Glucophage will help control diabetes but will not cure it. Most people will need to take Glucophage on a long-term basis.
If you forget to take Glucophage
If it is almost time for your next dose, skip the dose you missed and take your next dose when you are meant to. Otherwise, take the missed dose as soon as you remember (with food), and then go back to taking your tablets as you would normally. Do not take a double dose to make up for the dose you missed. If you are not sure what to do, ask your doctor or pharmacist.
If you take too much Glucophage (overdose)
Immediately telephone your doctor, or the Poisons Information Centre, or go to Accident and Emergency at the nearest hospital, if you think you or anyone else may have taken too much Glucophage. Do this even if there are no signs of discomfort or poisoning. If you take too much Glucophage, you may feel sleepy, 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).
Glucophage helps most people with diabetes but it may have unwanted side effects in some people. All medicines can have side effects. Tell your doctor if you notice any of the following and they worry you:
- stomach upset such as feeling sick (nausea), vomiting
- taste disturbance, loss of appetite
- red skin rash
The side effects listed above are generally mild. Stomach upset and diarrhoea are common but usually short-lived. Taking Glucophage with meals can help reduce nausea and diarrhoea. Skin rash has been reported rarely.
After taking Glucophage
Storage: Keep Glucophage where children cannot reach it. Keep your tablets in a cool dry place where the temperature stays below 25 degrees C. Do not store Glucophage or any other medicine in the bathroom or near a sink.
Disposal: If your doctor tells you to stop taking Glucophage, or your tablets have passed their expiry date, ask your pharmacist what to do with any that are left over.