Metformin 500mg Tablets

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PACKAGE LEAFLET: INFORMATION FOR THE USER

METFORMIN 500MG AND 850MG TABLETS

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.

• If you have further questions, ask your doctor or pharmacist

• 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 get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet (see section 4.)

What is in this leaflet

1. What metformin is and what it is used for

2. What you need to know before you take metformin

3. How to take metformin

4. Possible side effects

5. How to store metformin

6. Contents of the pack and other information

. WHAT METFORMIN IS AND WHAT IT IS USED FOR

The name of this medicine is Metformin 500mg or 850mg Tablets (called metformin in this leaflet). It belongs to a group of medicines called biguanides (a type of oral hypoglycaemic).

Insulin is a hormone produced by the pancreas that makes your body take in glucose (sugar) from the blood. Your body uses glucose to produce energy or stores it for future use.

If you have diabetes, your pancreas does not make enough insulin or your body is not able to properly use the insulin it produces. This leads to a high level of glucose in your blood.

Metformin works by improving the sensitivity of your body to insulin. It helps to lower your blood glucose to as normal a level as possible.

If you are an overweight adult, taking metformin over a long period of time also helps to lower the risk of complications associated with diabetes. Metformin is associated with either a stable body weight or modest weight loss.

Metformin is used to treat patients with type 2 diabetes (also called ‘non-insulin-dependent diabetes’) when diet and exercise alone have not been enough to control your blood glucose levels. It is used particularly in overweight patients.

• Adults can take metformin on its own or together with other medicines to treat diabetes (medicines taken by mouth or insulin).

• Children 10 years and over and adolescents can take metformin on its own or together with insulin.

2. WHAT YOU NEED TO KNOW BEFORE YOU TAKE METFORMIN

Do not take Metformin

• if you are allergic to metformin or any of the other ingredients in this medicine (see section ⁶⁾.

• if you have liver or kidney problems (glomerular filtration rate below 45 ml/min).

• 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 recently had a severe injury (shock), which may lead to kidney problems and put you at risk of lactic acidosis (see ‘Warnings and precautions’).

• if you lost too much water from your body (dehydration), e.g. due to long-lasting or severe diarrhoea, or if you have vomited several times in a row. Dehydration may lead to kidney problems, which can put you at risk for lactic acidosis (see ‘Warnings and precautions’).

• if you have a severe infection, such as an infection affecting your lung or bronchial system or kidney. Severe infections may lead to kidney problems, which can put you at risk for lactic acidosis (see ‘Warnings and precautions’).

• if you are treated for acute heart failure or have recently had a heart attack, have severe problems with your circulation (such as shock) or have breathing difficulties. This may lead to a lack of oxygen supply to tissue which can put you at risk for lactic acidosis (see ‘Warnings and precautions’).

• if you drink a lot of alcohol.

If any of the above applies to you, talk to your doctor before you start taking this medicine.

Warnings and precautions_

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 other medical conditions in which a region of the body is deprived with a lack of oxygen supply (such as acute heart disease).

It is important for 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 breathing. Further symptoms are reduced body temperature and heartbeat. If you experience some of these symptoms, you should seek immediate 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 heartbeat, vision disorders or difficulty in concentration, it usually helps to eat or drink something containing sugar.

Make sure you ask your doctor for advice if:

• you need to have an examination such as an X-ray or scan involving the injection of contrast medicines that contain iodine into your bloodstream.

• you need to have major surgery.

You need to 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.

Other medicines and metformin

If you need to have an injection of contrast medicines that contain iodine into your bloodstream, for example for examinations such as X-ray or scan, you must stop taking metformin for a certain period of time before and after (at least 48h) the examination (see ‘Make sure you ask your doctor for advise’ above).

Tell your doctor if you take any of the following medicines and metformin at the same time. You may need more frequent blood glucose tests or your doctor may adjust the dosage of metformin:

• diuretics (used to remove water from the body by making more urine)

• ACE inhibitors such as enalapril (used to treat high blood pressure)

• beta-2-agonists such as salbutamol or terbutaline (used to treat asthma)

• corticosteroids (used to treat a variety of conditions, such as severe inflammation of the skin or in asthma)

• other medicines used to treat diabetes

Tell your doctor or pharmacist if you are taking or have recently taken any other medicine, including medicines obtained without a prescription.

Metformin 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 machines

Metformin on its own does not cause hypoglycaemia (a blood glucose level which is too low). This means that it will not affect your ability to drive or use machines.

However, take special care if you take metformin together with other medicines to treat diabetes that can cause hypoglycaemia (such as sulphonylureas, insulin, meglitinides). Symptoms of hypoglycaemia include weakness, dizziness, increased sweating, fast heartbeat, vision disorders or difficulty in concentration. Do not drive or use machine if you start to feel these symptoms.

3. HOW TO TAKE METFORMIN

Always take metformin exactly as your doctor has told you. You should check with your doctor or pharmacist if you are not sure.

Metformin cannot replace the benefits of a healthy lifestyle. Continue to follow any advice about diet that your doctor has given you and get some regular exercise.

How much to take Adults

• The usual starting dose is 500mg or 850mg metformin 2 or 3 times a day.

• The maximum daily dose is 3000mg taken as 3 divided doses.

Patients with renal impairment

• In renally impaired patients with a GFR between 45 and 60ml/min, the starting dose is 500mg or 850mg metformin, once daily.

• The maximum dose is 1000mg daily, given as 2 divided doses.

• The renal function should be closely monitored (every 3-6 months)

Children 10 years and over and adolescents

• The usual starting dose is 500mg or 850mg metformin once a day.

• The maximum daily dose is 2000mg 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.

Children aged under 10 years

Metformin is not recommended for use in children under 10 years old.

Taking metformin with insulin

If you take insulin too, your doctor will tell you how to start metformin.

Monitoring

• You 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.

How to take metformin

Take metformin with or after a meal. This will avoid you having side effects affecting your digestion.

Do not crush or chew the tablets. Swallow each tablet with a glass of water.

• If you take one dose a day, take it in the morning (breakfast)

• If you take 2 divided doses a day, take them in the morning (breakfast) and evening (dinner)

• If you take 3 divided doses a day, then take them in the morning (breakfast), at noon (lunch) and evening (dinner)

If, after some time, you think that the effect of metformin is too strong or too weak, talk to your doctor or pharmacist.

If you take more metformin than you should

If you have taken more metformin than 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 heartbeat.

If you experience some of these symptoms, you should seek immediate 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

If you forget to take a dose, take it as soon as you remember, with your next meal. However, if it is time for your next dose, do not take the missed dose. Take only a single dose as usual.

Do not take a double dose to make up for a forgotten dose.

If you stop taking metformin

Keep taking this medicine until your doctor tells you to stop.

If you have any further questions on the use of this medicine, ask your doctor or pharmacist.

. POSSIBLE SIDE EFFECTS

Like all medicines metformin can cause side effects, although not everybody gets them.

Other side effects:

Very common (may affect more than 1 in 10 people):

• digestive problems such as feeling sick (nausea), being sick (vomiting), diarrhoea, stomach ache (abdominal pain) and loss of appetite. These side effects are most likely to happen at the start of treatment. It helps if you spread the doses over the day and if you take metformin with or straight after a meal. If symptoms continue, stop taking metformin and talk to your doctor.

Common (may affect up to 1 in 10 people):

• changes in taste.

Very rare (may affect up to 1 in 10,000 people):

• lactic acidosis. This is a very rare but serious complication particularly if your kidneys are not working properly.

Symptoms of lactic acidosis are non-specific such as vomiting, stomach ache (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 heartbeat.

• abnormalities in liver function tests or hepatitis (inflammation of the liver; 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.

• skin reactions such as redness of the skin (erythema), itching or itchy rash (hives).

• low vitamin B12 levels in the blood. Over time this may lead to anaemia, a sore mouth or tongue or possibly numbness or tingling in the limbs.

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 the Yellow card

Scheme at: www.mhra.gov.uk/yellowcard.

By reporting side effects you can help provide more information on the safety of this medicine.

5. HOW TO STORE METFORMIN

• Keep out of the sight and reach of children. If a child is treated with metformin, parents and caregivers are advised to oversee how this medicine is used.

• Do not store above 25°C. Store in the original package.

• Do not take this medicine after the expiry date which is stated on the carton after ‘EXP’. The expiry date refers to the last day of that month.

• Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines you no longer use. These measures will help protect the environment.

6. CONTENTS OF THE PACK AND OTHER INFORMATION

What Metformin 500mg or 850mg Tablets contains:

The active substance is metformin hydrochloride. Each tablet contains 500mg or 850mg of metformin hydrochloride.

The other ingredients are sodium starch glycollate, maize starch, providone, colloidal anhydrous silica, magnesium stearate, methylhydropropylcellulose, titanium dioxide (E171), propylene glycol, Macrogol 6000 and purified talc.

What Metformin 500mg or 850mg Tablets look like and contents of the pack

Metformin 500mg Tablets are white, biconvex, round, film-coated tablets. They are marked S137 on one side.

Metformin 850mg Tablets are white biconvex, round, film-coated tablets. They are marked S138 on one side.

Metformin 500mg Tablets are available in blister packs of 28, 84, 300 and 500 tablets.

Metformin 850mg Tablets are available in blister packs of 28, 84, 300 and 500 tablets.

(Not all pack sizes may be marketed.)

Marketing Authorisation Holder and Manufacturer

Marketing Authorisation Holder

Winthrop Pharmaceuticals, PO Box 611, Guildford, Surrey, GU1 4YS, UK.

Zentiva, One Onslow Street, Guildford, Surrey, GU1 4YS, UK Manufacturer

Zentiva, One Onslow Street, Guildford, Surrey, GU1 4YS, UK This leaflet was prepared in September 2015