PATIENT INFORMATION LEAFLET

Metformin (also referred to as Metformin Hydrochloride throughout this leaflet) is an antidiabetic drug which belongs to a group of medicines called biguanides. It works by lowering your blood-sugar level.

If your blood sugar levels are not controlled, it can lead to serious problems such as kidney damage, amputations and blindness. Metformin is thought to work by decreasing the amount of sugar absorbed from food through the stomach, by helping the body respond better to the insulin it makes naturally and by decreasing the amount of sugar produced by the liver and kidneys.

Metformin is used to treat non-insulin dependent diabetes (also called type 2 diabetes) when an improvement in diet and exercise has failed to reduce blood sugar levels, particularly if overweight.

It may be used alone as initial therapy or along with other oral antidiabetic drugs or with insulin. Children 10 years and over and adolescents can take Metformin on its own or together with insulin.

Sometimes Metformin Tablets are also used to treat patients suffering from insulin dependent diabetes, who are overweight (obese) and whose symptoms are poorly controlled.

[2 What you need to know before you take Metformin

Do not take Metformin Tablets if:

■    you are allergic to metformin hydrochloride or any of the other ingredients of this medicine (listed in section 6 'Contents of the pack and other information').

■    you have very high blood sugar levels (hyperglycaemia) or ketoacidosis, which can lead to diabetic pre-coma. Diabetic ketoacidosis is a condition in which substances called 'ketone bodies' accumulate in the blood, due to consistently high blood glucose levels. Symptoms include stomach pain, fast and deep breathing, sleepiness or unusual fruity odour of the breath.

■    you have kidney or liver disease.

■    you have 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 in oxygen supply to tissue which can put you at risk for lactic acidosis (see 'Warnings and precautions' below).

■    you suffer from alcoholism.

■    you suffer from a loss or lack of water in the body (dehydration), such as 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' below).

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

Warnings and precautions

Talk to your doctor before taking Metformin:

■    if you have diabetes and kidney problems as you are more at risk of developing a rare but serious side effect known as 'lactic acidosis'. The risk of lactic acidosis is also increased with uncontrolled diabetes, an increased level of ketones in your blood (ketosis), prolonged fasting, drinking an excessive amount of alcohol or liver problems. Symptoms of lactic acidosis are vomiting, bellyache (abdominal pain) with muscle cramps, a general feeling of not being well with severe tiredness, and difficulty in breathing (see section 4 'Possible side effects').

If this happens to you, you may need immediate hospital treatment, as lactic acidosis may lead to coma. Stop taking Metformin immediately and contact a doctor or the nearest hospital straight away.

■    if you have kidney problems, particularly if you are elderly.

■    if you continuously use Metformin. It may

other medicines used to treat diabetes, such as insulin, sulphonylureas or meglitinides.

■    if you are to undergo diagnostic tests (using iodinated contrast media) or you need to have major surgery, you must tell your doctor. You will need to stop taking Metformin Hydrochloride for a certain period of time before and after the diagnostic tests or surgery.

Monitoring kidney function and diabetes

■    Kidney function: As Metformin is excreted by the kidney your doctor will test your kidney function. This should be done before starting treatment and regularly thereafter: once a year for normal kidney function and two to four times a year if you have kidney problems or you are elderly

■    Diabetes: Usual laboratory tests for diabetes monitoring should be performed regularly

Other medicines and Metformin

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

If you are to undergo diagnostic tests (using iodinated contrast media) or you need to have major surgery, you must tell your doctor. You will need to stop taking Metformin Hydrochloride for a certain period of time before and after the diagnostic tests or surgery (see 'Warnings and precautions' above)

Other medicines may interfere with the actions of your Metformin Tablets. You should tell your doctor if you are taking 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:

■    other medicines used to treat diabetes such as glibenclamide (known as sulphonylureas), meglitinides or insulin.

■    medicines called 'diuretics' that are used to treat fluid retention or high blood pressure such as furosemide

■    medicines to thin the blood such as warfarin (anticoagulants).

■    cimetidine, for stomach ulcers and indigestion.

■    medicines for inflammation and allergic reactions, such as betamethasone (glucocortcoids).

Metformin and alcohol

You should not drink alcohol whilst taking Metformin Hydrochloride. Alcohol may increase the risk of lactic acidosis especially if you have liver problems, you are undernourished or you are fasting. This also applies to medicines that contain alcohol.

Pregnancy and breast-feeding

If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor for advice before taking this medicine.

Pregnancy

If you are pregnant or you are planning to become pregnant you should not take Metformin. However, your diabetes needs to be controlled during pregnancy and this should be done by taking insulin.

Breast-feeding

You should not take Metformin whilst breastfeeding unless your doctor thinks the benefits outweigh the risks.

Ask your doctor or pharmacist for advice before taking any medicine.

Driving or operating machines

If you are taking Metformin on its own it should not affect your ability to drive or operate machinery.

However, if you are taking Metformin together with other medicines to treat diabetes (such as sulphonylureas, insulin or meglitinides) it may cause hypoglycaemia (low blood glucose level). Symptoms of hypoglycaemia include weakness, dizziness, increased sweating, fast heart beat,

vision disorders or difficulty in concentrating. If you have any of these symptoms do not drive or use machinery.

\M How to take Metformin

Always take this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure.

■    Metformin Tablets are for oral use only

■    Recommended to be taken with or after meals

The recommended dose is:

Adults

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

The maximum dose is 3000mg a day taken as 3 divided doses.

After taking Metformin for 10 to 15 days the doctor will adjust the dose based on blood sugar measurements.

Older patients and patients with kidney problems

Your doctor will choose the correct dosage depending on the seriousness of your kidney problem, and will need to have regular checkups to monitor your kidney function.

Use in children (10 years and above) and adolescents:

The normal dose is 500mg or 850mg, once a day. The maximum dose is 2000mg a day taken as 2 or 3 divided doses.

After taking Metformin for 10 to 15 days the doctor will adjust the dose based on blood sugar measurements.

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.

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

If you have taken more Metformin than you should

If you accidentally take too many tablets, consult your doctor or the nearest hospital casualty department immediately. Take this leaflet or some tablets with you so that people will know what you have taken.

An overdose of Metformin may lead to lactic acidosis (for symptoms see Section 4 'Possible side effects')

If you forget to take Metformin

Take it as soon as you remember, unless it is time for your next dose. Do not take a double dose to make up for a forgotten dose.

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

Possible side effects

Serious side effect

Although very rare, some people have developed a condition known as lactic acidosis whilst taking Metformin Tablets. Although lactic acidosis is a serious condition, it is not normally a problem with metformin, provided it is correctly treated.

Lactic acidosis is caused by a build up of lactic acid in the blood (produced when glucose is turned into energy without oxygen).

Possible symptoms of lactic acidosis:

■    unexplained weight loss

■    feeling sick (nausea)

■    being sick (vomiting)

■    general feeling of being unwell

■    pain in the belly region

■    difficulty breathing

■    muscle cramp

■    severe weakness or loss of strength

■    feeling cold

If you have or think you may have    lactic

acidosis, you should go to the hospital immediately as it is a medical emergency.

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

■    feeling sick (nausea)

■    being sick (vomiting)

■    diarrhoea

■    abdominal pain

■    loss of appetite

These side effects usually occur at the start of treatment. You should continue to take your medicine as they normally disappear after a short time. They may be avoided by taking your medicine with or after food and in 2 or 3 divided doses.

Common side effects (may affect up to 1 in 10 people)

■    change in taste

Very rare side effects (may affect up to 1 in

10,000 people)

■    skin reactions such as flushing of the skin, itching or itchy rash

■    decreased vitamin B12 absorption

■    abnormal liver function test (detected through blood test) or inflammation of the liver (hepatitis), which may cause tiredness, loss of appetite, weight loss or yellowing of the skin or whites of the eyes

There are only isolated reports of abnormal liver function or hepatitis and these have been resolved when treatment was stopped. If this happens to you, stop taking Metformin and talk to your doctor

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 internet at (www.mhra.gov.uk/yellowcard). By reporting side effects you can help provide more information on the safety of this medicine.

How to store Metformin

Keep this medicine out of the sight and reach of children.

Store below 25°C, store in the original package in order to protect from light.

Do not use this medicine after the expiry date which is stated on the carton/blister after EXP. The expiry date refers to the last day of that month.

Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.

Contents of the pack and other information

What Metformin Tablets contain:

■    The active substance is Metformin Hydrochloride.

Each tablet contains 500mg of Metformin Hydrochloride.

■    The other ingredients are: povidone K30, microcrystalline cellulose, colloidal anhydrous silica, magnesium stearate, sodium starch glycollate, ethyl cellulose 7 cps, hypromellose, propylene glycol and titanium dioxide (E171).

What Metformin Tablets look like and the contents of the pack:

Metformin Tablets approximately 12mm, white, round, convex, film-coated tablets marked 17 LG on the one side.

They are available in pack sizes of 28, 50, 56,

84, 100 and 500 tablets.

Not all pack sizes may be marketed.

REMEMBER

This medicine is only for YOU. Only a doctor can prescribe it, so never offer it to anybody else. It may harm them, even if their symptoms seem to be the same as yours.

Marketing Authorisation Holder & Manufacturer

Tillomed Laboratories Ltd 3 Howard Road,

Eaton Socon, St Neots Cambridgeshire PE19 8ET, UK

Product Licence Number:

PL 11311/0196: Metformin Hydrochloride 500mg Tablets

Date of approval May 2014

Hard to Read? Phone 0800 970 6115 for help

Till-Ipc-V.1s