Metformin 500mg Tablets
PACKAGE LEAFLET: INFORMATION FOR THE USER METFORMIN 500 mg TABLETS and METFORMIN 850 mg TABLETS
Metformin Hydrochloride
Read all of this leaflet carefully before you start taking this
medicine because it contains important information for you.
• Keep this leaflet. You may need to read it again
• This medicine has been prescribed for you only. Do not pass it on to others. It may harm them, even if their signs of illness are the same as yours
• If you have any further questions, please ask your doctor or pharmacist
• If any of the side effects gets serious, or if you notice any side effects not listed in this leaflet, please tell your doctor or pharmacist
What is in this leaflet
1. What Metformin Tablet is and what it is used for
2. What you need to know before you take Metformin Tablets
3. How to take Metformin Tablets
4. Possible side effects
5. How to store Metformin Tablets
6. Contents of the pack and other information
These tablets are available in two different strengths and your doctor will have decided which is the most suitable for you. Each tablet contains either 500 mg or 850 mg of the active ingredient, metformin hydrochloride.
Metformin is one of a group of medicines called oral hypoglycaemics, which work by reducing the level of sugar in the blood.
Metformin Tablets are used for the treatment of a type of diabetes which usually only occurs in adults, and is not severe enough to need insulin, but which does not respond to dietary measures alone. In some patients metformin may be used in combination with other anti-diabetic medicines called sulphonylureas.
Do not take Metformin tablets:
• If you know you are allergic to metformin, or to any of the other ingredients (these are listed in section 6)
• If you have failed to respond to treatment with other antidiabetic medicines called sulphonylureas
• If you have ever fainted or even suffered a coma from having diabetes
• If you have uncontrolled diabetes, with e.g. severe hyperglycaemia (high blood glucose), nausea, vomiting, dehydration, rapid weight loss or ketoacidosis. Ketoacidosis is a condition in which substances called ‘ketone bodies’ accumulate in the blood and which can lead to diabetic pre-coma. Symptoms include stomach pain, fast and deep breathing, sleepiness or unusual fruity odour of the breath.
• If you have problems with your liver or kidneys (glomerular filtration rate below 45 ml/min)
• If you have an acute or chronic disease which could cause decreased oxygen supply (hypoxia), like heart failure, respiratory failure or a recent heart attack or you have breathing problems.
This may lead to a lack in oxygen supply to tissue which can put you at risk for lactic acidosis (see 'Warnings and precautions')
• If you are pregnant or think you may be pregnant
• If you suffer from alcoholism or acute alcohol intoxication
• If you have any problems with your circulation, causing for example, frequent cramp in your calves or leg ulcers that do not heal
• If you have an infection, a fever, are suffering from shock or trauma or are unwell in any other way. Severe infections may lead to kidney problems, which can put you at risk for lactic acidosis (see 'Warnings and precautions')
• If you suffer from an inflamed pancreas (pancreatitis)
• If you are on a special low calorie diet (less than 1000 calories per day or 4200 KJ per day)
• If you are dehydrated (feeling extremely thirsty) or severe diarrhoea or you have vomited several times in a row. Dehydration may lead to kidney problems, which can put you at risk for lactic acidosis
You must check with your doctor before taking these tablets If
you are breast-feeding.
Other special warnings
• If you are going to have an operation requiring an anaesthetic or you are to undergo a scan requiring injection of a dye, you must ensure the doctor in charge is aware you are taking Metformin Tablets (as they will need to be stopped up to 48 hours before the procedures)
• You should not drink alcohol while taking Metformin Tablets
• Patients who are already on insulin should only be started on a course of treatment with metformin in hospital
• If you are taking these tablets continuously, your doctor will perform regular blood tests to check your Vitamin B12 levels and your kidney function
• If you are an elderly patient (approximately over the age of 65 years) your doctor will perform blood and urine tests to check your kidney function before starting metformin
If any of the conditions above apply to you, please discuss your treatment with your doctor before taking this medicine.
Warnings and precautions
Talk to your doctor or pharmacist before taking Metformin Tablets.
Please note the following particular risk of lactic acidosis.
Metformin may cause a very rare, but very serious complication called lactic acidosis, particularly if your kidneys are not working properly. The risk of developing lactic acidosis is also increased with uncontrolled diabetes, prolonged fasting or alcohol intake, body fluid deficit (dehydration) due to severe diarrhoea or vomiting, liver problems and any medical conditions in which a region of the body is deprived with a lack of oxygen supply (such as acute severe heart diseases).
It is important to you to comply with your medication intake, dietary instructions and regular exercise program because this can reduce the risk of lactic acidosis.
The onset of lactic acidosis can be subtle and the symptoms can be non-specific such as vomiting, bellyache (abdominal pain) with muscle cramps, a general feeling of not being well with severe tiredness, and difficulty in breathing. Further symptoms are reduced body temperature and heart beat. If you experience some of these symptoms, you should seek immediately medical attention, as lactic acidosis may lead to coma. Stop taking Metformin immediately and contact a doctor or the nearest hospital straight away.
Metformin on its own does not cause hypoglycaemia (a blood glucose level which is too low). However, if you take metformin together with other medicines to treat diabetes that can cause hypoglycaemia (such as sulphonylureas, insulin, meglitinides), there is a risk of hypoglycaemia. If you experience symptoms of hypoglycaemia such as weakness, dizziness, increased sweating, fast heart beating, visions disorders or difficulty in concentration, it usually helps to eat or drink something containing sugar.
Other medicines and Metformin Tablets
Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines.
Metformin Tablets and other medicines you may be taking may affect how each other work. Make sure your doctor knows if you are taking any of the following:
• Insulin, other diabetic drugs and guar
• Monoamine-oxidase inhibitors (MAOls) or other medicines to treat depression or psychoses such as chlorpromazine
• Aspirin or any other non-steroidal medicines for pain and inflammation
• ACE inhibitors and beta-blockers for high blood pressure
• Other medicines for high blood pressure eg. clonidine, reserpine, guanethidine or diazoxide
• Thiazides and loop diuretics (water tablets)
• Beta-2 agonists such as salbutamol or terbutaline (used to treat asthma)
• Medicines for lowering cholesterol in the blood such as clofibrate or nicotinic acid derivatives
• Cyclophosphamide (to control inflammation)
• Cimetidine (to treat stomach ulcers)
• Hormone drugs such as the contraceptive pill or hormone replacement therapy (HRT)
• Steroids such as prednisolone or hydrocortisone
• Oxytetracyciine (an antibiotic to treat infections)
• Phenprocoumone (an anticoagulant to thin the blood)
• Adrenaline and other sympathomimetics (used to treat allergic conditions and heart attacks)
• Glucagon (used to control low blood sugar levels)
• Thyroid hormones such as thyroxine
Continued, please turn over
Always tell your doctor or pharmacist about all the medicines you are taking. This means medicines you have bought yourself as well as those you have on prescription from your doctor.
Metformin tablet with food and drink
Do not drink alcohol when you take this medicine. Alcohol may increase the risk of lactic acidosis especially if you have liver problems or if you are undernourished. This also applies to medicines that contain alcohol.
Pregnancy and breast-feeding
During pregnancy, you need insulin to treat your diabetes. Tell your doctor if you are, you think you might be or are planning to become pregnant, so that he or she may change your treatment. This medicine is not recommended if you are breast-feeding or if you are planning to breast-feed your baby.
Driving and using machinery
Metformin Tablets taken on their own should not affect your ability to drive or operate machinery, but if you are also taking them with another medicine (sulphonylureas or insulin) to lower blood sugar levels, it is possible the combined effect of these medicines may make some patients feel faint or dizzy. If this happens do not drive or operate machinery until you feel better.
Always take this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure. The tablets should be swallowed whole with a glass of water during or after meals.
The doctor will decide what dose you need to take. Always take the tablets exactly as the doctor has told you. The dose will be on the pharmacist's label. if you are not sure, ask your doctor or pharmacist. Carry on taking them for as long as you have been told unless you have any problems. In that case, check with your doctor.
The recommended dose for adults is: One or two 500 mg tablets, or one 850 mg tablet each day. The dose will be gradually increased by your doctor until the right dose to control your symptoms is found. In most cases symptoms can be eventually controlled with three 500 mg tablets or two 850 mg tablets each day in divided doses. The maximum daily doses are six 500 mg tablets or three 850 mg tablets.
Use in children 10 years and over and adolescents usually start with 500 mg or 850 mg Metformin tablet once a day. The maximum daily dose is 2000 mg taken as 2 or 3 divided doses. Treatment of children between 10 and 12 years of age is only recommended on specific advice from your doctor, as experience in this age group is limited.
In renal impaired patients with a GFR between 45 and 60 ml/min, the starting dose is 500 mg or 850 mg metformin, once daily. The maximum dose is 1000 mg daily, given as 2 divided doses. The renal function should be closely monitored (every 3 - 6 months). If you take insulin too, your doctor will tell you how to start metformin.
Monitoring
• Your doctor will perform regular blood glucose tests and will adapt your dose of metformin to your blood glucose levels. Make sure that you talk to your doctor regularly. This is particularly important for children and adolescents or if you are an older person.
• Your doctor will also check at least once a year how well your kidneys work. You may need more frequent checks if you are an older person or if your kidneys are not working normally.
If you take more Metformin Tablets than you should
If you have taken more metformin that you should have, you may experience lactic acidosis. Symptoms of lactic acidosis are non-specific such as vomiting, bellyache (abdominal pain) with muscle cramps, a general feeling of not being well with severe tiredness, and difficulty in breathing. Further symptoms are reduced body temperature and heart beat. If you experience some of these symptoms, you should seek immediately medical attention, as lactic acidosis may lead to coma. Stop taking Metformin immediately and contact a doctor or the nearest hospital straight away.
If you forget to take Metformin Tablets
If you miss a dose, take the missed dose as soon as you remember unless it is nearly time for your next dose. Do not take a double dose to make up for the forgotten dose.
If you suddenly experience any of the following effects:
• Muscle pains or spasms, hyperventilation (over breathing), tiredness, clouding of consciousness, severe abdominal pain or severe indigestion.
You must IMMEDIATELY go to the nearest hospital casualty department, as these may be symptoms of the very rare but serious condition of lactic acidosis.
The most common side effects (usually when you first start taking metformin) are:
• Nausea, vomiting, abdominal pain, diarrhoea, loss of appetite or a metallic taste.
If these side-effects occur they usually get better spontaneously so you should continue to take the tablets unless your stomach upset is severe or shows no signs of getting better after a few days - in this case contact your doctor.
Very rarely liver disorders such as inflammation of the liver may occur or blood tests to check your liver may have abnormal results, this may cause tiredness, loss of appetite, weight loss, with or without yellowing of the skin or whites of the eyes. If this happens to you, stop taking metformin and talk to your doctor.
Very rarely skin reactions such as redness, itching or hives or allergic reactions may occur. If you notice a rash ask your doctor for advice about continuing to take the tablets.
Prolonged treatment with Metformin Tablets can result in a lack of Vitamin B12 and this may cause anaemia. Your doctor will carry out regular blood tests to check for this. If you notice any unwanted effects, even one not mentioned here, please go and see your doctor.
Additional side effects in children and adolescents
Limited data in children and adolescents showed that adverse events
were similar in nature and severity to those reported in adults.
Reporting of side effects
If you get any side effects, talk to your doctor or pharmacist.
This includes any possible side effects not listed in this leaflet.
You can also report side effects directly via Yellow Card Scheme, Website: www.mhra.gov.uk/yellowcard. By reporting side effects you can help provide more information on the safety ofthis medicine.
Keep out of the sight and reach of children - preferably in a locked cupboard or cabinet.
Do not store above 25°C. Store the tablets in the original blister pack.
Do not take the tablets after the expiry date shown on the carton.
The expiry date refers to the last day of that month. If your doctor tells you to stop taking the tablets, please take any unused medicine back to your pharmacist to be destroyed. Do not throw away any medicines via wastewater. Ask your pharmacist how to throw away medicines you no longer use. These measures will help to protect the environment.
Like all medicines, this medicine can cause side effects, although not everybody gets them.
What Metformin Tablet contains
Each tablet contains either 500 mg or 850 mg of the active ingredient, metformin hydrochloride. The tablets also contain sodium starch glycollate, maize starch, povidone, colloidal anhydrous silica, magnesium stearate, hypromellose, titanium dioxide (E171), propylene glycol, macrogol 6000 and purified talc.
What Metformin Tablets look like and contents of the pack.
Metformin Tablets are round, white, film-coated tablets.
The 500 mg strength tablets are marked with "500" on one side and the 850 mg strength tablets are marked with "850" on one side.
They are available in blister packs containing 28, 56 or 84 tablets (500 mg) and 28,42, 56 or 84 tablets (850 mg).
Not all pack sizes are marketed.
Marketing Authorisation Holder and Manufacturer
The marketing authorisation holder is Special Concept Development (UK)
Ltd, Colonial Way, Watford, Hertfordshire, WD24 4YR, UK.
Manufactured by RX Farma Ltd, Unit 3 Colonial Way, Watford, WD24 4YR
Product licence numbers
Metformin 500mg Tablets - PL 36722/0030
Metformin 850mg Tablets - PL 36722/0031
For any information about this medicine, please contact the g
Marketing Authorisation Holder.
The Leaflet was last reviewed in September 2015
If you would like this leaflet in a different format, please contact
the licence holder at the above address.