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Metformin Flamingo SR 750 mg prolonged release tablets

Active Ingredient:
ATC code: 
A10BA02
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About Medicine
The Patient Information Leaflet (PIL) is the leaflet included in the pack with a medicine.
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Last updated on emc: 12 Sep 2025

Below is a text only representation of the Patient Information Leaflet (ePIL).

The text only version may be available in large print, Braille or audio CD. For further information call emc accessibility on {phone} 0800 198 5000. The product code(s) for this leaflet is: PL 43461/0171.

Metformin Flamingo SR 500 mg, 750 mg and 1000 mg Prolonged Release Tablets

Package Leaflet: Information for the user

Metformin Flamingo SR 500mg, 750mg and 1000mg prolonged release 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.
  • If you have any further questions, ask your doctor or pharmacist.
  • This medicine has been prescribed for you only. Do not pass it onto 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.
  • Metformin Flamingo SR 500mg, 750mg and 1000mg prolonged release tablets are referred as Metformin Flamingo SR in this leaflet.

What is in this leaflet:

1. What Metformin Flamingo SR are and what they are used for
2. What you need to know before you take Metformin Flamingo SR
3. How to take Metformin Flamingo SR
4. Possible side effects
5. How to store Metformin Flamingo SR
6. Contents of the pack and other information

1. What Metformin Flamingo SR are and what they are used for

Metformin Flamingo SR prolonged release tablets contain the active ingredient metformin hydrochloride and belong to a group of medicines called biguanides, used in the treatment of Type 2 (non-insulin dependent) diabetes mellitus.

Metformin Flamingo SR is used together with diet and exercise to lower the risk of developing Type 2 diabetes in overweight adults, when diet and exercise alone for 3 to 6 months have not been enough to control blood glucose (sugar). You are at high risk of developing Type 2 diabetes if you have additional conditions like high blood pressure, age above 40 years, and an abnormal amount of lipids (fat) in the blood or a history of diabetes during pregnancy.

The medicine is particularly effective if you are aged below 45 years, are very overweight, have high blood glucose levels after a meal or developed diabetes during pregnancy.

Metformin Flamingo SR is used for the treatment of Type 2 diabetes when diet and exercise changes alone have not been enough to control blood glucose (sugar). Insulin is a hormone that enables body tissues to take glucose from the blood and to use it for energy or for storage for future use. People with Type 2 diabetes do not make enough insulin in their pancreas 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 cause a number of serious long-term problems so it is important that you continue to take your medicine, even though you may not have any obvious symptoms. Metformin Flamingo SR makes the body more sensitive to insulin and helps return to normal the way your body uses glucose. Metformin Flamingo SR is associated with either a stable body weight or modest weight loss.

Metformin Flamingo SR Prolonged Release Tablets are specially made to release the drug slowly in your body and therefore are different to many other types of tablet containing metformin.

Polycystic ovary syndrome (PCOS) is a health condition that affects a woman's hormone levels, menstrual cycle, and ability to have children. Metformin Flamingo SR is used in women with PCOS to stimulate ovulation (release of an egg from the ovaries), and subsequently the chance of getting pregnant, alone or together with other treatment options

2. What you need to know before you take Metformin Flamingo SR
Do not take this medicine if :
  • you are allergic to metformin or to any of the other ingredients of this medicine (listed in section 6). An allergic reaction may cause a rash, itching or shortness of breath.
  • you have liver problems
  • you have severely reduced kidney function
  • you have uncontrolled diabetes, with, for example, severe hyperglycaemia (high blood gIucose), nausea, vomiting, diarrhoea, rapid weight loss, lactic acidosis (see 'Risk of lactic acidosis' below) 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 your breath developing an unusual, fruity smell.
  • you have lost too much water from your body (dehydration). which may happen in cases of prolonged or severe diarrhoea or repeated vomiting' Dehydration or shock may lead to kidney problems, which can put you at risk for lactic acidosis (see 'Warnings and precautions').
  • 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').
  • you have been treated for acute heart problems or have recently had a heart attack or have severe circulatory problems (such as shock) or 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').
  • you are a heavy drinker of alcohol.
  • you are under 18 years of age.

Warnings and precautions

Risk of lactic acidosis.

Metformin Flamingo SR may cause a very rare, but very serious side effect called lactic acidosis, particularly if your kidneys are not working properly. The risk of developing lactic acidosis is also increased with uncontrolled diabetes, serious infections, prolonged fasting or alcohol intake, dehydration (see further information below), liver problems and any medical conditions in which a part of the body has a reduced supply of oxygen (such as acute severe heart disease). If any of the above apply to you, talk to your doctor for further instructions.

Talk to your doctor promptly for further instructions if:

  • You are known to suffer from a genetically inherited disease affecting mitochondria (the energy-producing components within cells) such as MELAS syndrome (Mitochondrial Encephalopathy, myopathy, Lactic acidosis and Stroke-like episodes) or Maternal inherited diabetes and deafness (MIDD).
  • You have any of these symptoms after starting metformin: seizure, declined cognitive abilities, difficulty with body movements, symptoms indicating nerve damage (e.g. pain or numbness), migraine and deafness.

Stop taking Metformin Flamingo SR for a short time if you have a condition that may be

associated with dehydration (significant loss of body fluids) such as severe vomiting, diarrhea, fever, exposure to heat or if you drink less fluid than normal. Talk to your doctor for further instructions.

Stop taking Metformin Flamingo SR and contact a doctor or the nearest hospital immediately if you experience some of the symptoms of lactic acidosis, as this condition may lead to coma.

Symptoms of lactic acidosis include

  • vomiting
  • stomach ache (abdominal pain)
  • muscle cramps
  • a general feeling of not being well with severe tiredness
  • difficulty in breathing
  • reduced body temperature and heartbeat

Lactic acidosis is a medical emergency and must be treated in a hospital.

If you need to have major surgery you must stop taking Metformin Flamingo SR during and for some time after the procedure. Your doctor will decide when you must stop and when to restart your treatment with Metformin Flamingo SR.

During treatment with Metformin Flamingo SR, your doctor will check your kidney function at least once a year or more frequently if you are elderly and/or if you have worsening kidney function.

If you are older than 75 years, treatment with Metformin Flamingo SR should not be started to lower the risk of developing type 2 diabetes.

You may see some remains of the tablets in your stools.

Do not worry- this is normal for this type of tablet.

You should continue to follow any dietary advice that your doctor has given you and you should make sure that you eat carbohydrates regularly throughout the day.

Do not stop taking this medicine without speaking to your doctor.

Other medicines and Metformin Flamingo SR

If you need to have an injection of a contrast medium that contains iodine into your bloodstream, for example in the context of an X-ray or scan, you must stop taking Metformin FlamingoSR before or at the time of injection. Your doctor will decide when you must stop and when to restart your treatment with Metformin Flamingo SR.

Tell your doctor if you are taking, have recently taken or might take any other medicines. You may need more frequent blood glucose and kidney function tests, or your doctor may need to adjust the dosage of Metformin Flamingo SR. It is especially important to mention the following:

  • Medicines which increase urine production (diuretics (water tablets) such as furosemide).
  • Medicines used to treat pain and inflammation (NSAID and COX-2 inhibitors, such as ibuprofen and celecoxib).
  • Certain medicines for the treatment of high blood pressure (ACE inhibitors and angiotensin II receptor antagonists).
  • Steroids such as prednisolone, mometasone, beclometasone.
  • Sympathomimetic medicines including epinephrine and dopamine used to treat heart attacks and low blood pressure. Epinephrine is also included in some dental anaesthetics.
  • Medicines that may change the amount of Metformin Flamingo SR in your blood, especially if you have reduced kidney function (such as verapamil, rifampicin, cimetidine, dolutegravir, ranolazine, trimethoprim, vandetanib, isavuconazole, crizotinib, olaparib).

Metformin Flamingo SR with alcohol

Avoid excessive alcohol intake while taking Metformin Flamingo SR since this may increase the risk of lactic acidosis (see section 'Warnings and precautions').

Pregnancy and breast-feeding

If you are pregnant, think you may be pregnant or are planning to have a baby, speak to your doctor in case any changes will be needed to your treatment or monitoring of your blood glucose levels.

This medicine is not recommended if you are breast-feeding or if you are planning to breast-feed your baby.

Women of childbearing potential:

Metformin Flamingo SR can stimulate ovulation (release of an egg from the ovaries), in women who do not ovulate properly. Beware of an increased chance of becoming pregnant when using Metformin Flamingo SR.

Driving and using machines

Metformin Flamingo SR taken on its own does not cause 'hypos' (symptoms of low blood sugar or hypoglycaemia, such as faintness, confusion and increased sweating) and therefore should not affect your ability to drive or use machinery.

You should be aware, however, that Metformin Flamingo SR taken with other antidiabetic medicines can cause hypos, so in this case you should take extra care when driving or operating machinery.

Information about ingredient of Metformin Flamingo SR This medicine contains less than 1 mmol sodium (23 mg) per dosage unit, that is to say it is essentially 'sodium free'.

3. How to take Metformin Flamingo SR

Your doctor may prescribe Metformin Flamingo SR for you to take on its own, or in combination with other oral antidiabetic medicines or insulin.

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

Swallow the tablets whole with a glass of water, do not chew.

Recommended dose

Usually you will start treatment with 500 milligrams Metformin Flamingo SR daily. After you have been taking Metformin Flamingo SR SR for about 2 weeks, your doctor may measure your blood sugar and adjust the dose. The maximum daily dose is 2000 milligrams of Metformin Flamingo SR. If you have reduced kidney function, your doctor may prescribe a lower dose.

Normally, you should take the tablets once a day, with your evening meal.

In some cases, your doctor may recommend that you take the tablets twice a day. Always take the tablets with food.

Polycystic ovary syndrome (PCOS)

The usual dose is 1500-2000 mg metformin hydrochloride taken once a day with the evening meal. You should check with your doctor or pharmacist when to stop taking the medicine.

If you take more Metformin Flamingo SR than you should

If you take extra tablets by mistake you need not worry, but if you have unusual symptoms, contact your doctor.

If the overdose is large, lactic acidosis is more likely.

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. If you experience some of these symptoms, you should immediately seek medical attention, as lactic acidosis may lead to coma. Stop taking Metformin Flamingo SR immediately and contact a doctor or the nearest hospital straightaway.

If you forget to take Metformin Flamingo SR

Take it as soon as you remember with some food. Do not take a double dose to make up for a forgotten dose.

4. Possible side effects

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

The following side effects may occur:

Metformin Flamingo SR may cause a very rare (may affect up to 1 user in 10,000) but very serious side effect called lactic acidosis (see section 'Warnings and precautions').

If this happens, you must stop taking Metformin Flamingo SR and contact a doctor or the nearest hospital immediately, as lactic acidosis may lead to coma.

Metformin Flamingo SR may cause abnormal liver function tests and hepatitis (inflammation of the liver) If you develop yellowing of the eyes and/or skin contact your doctor immediately.

Other possible side effects are listed by frequency as follows:

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

  • Diarrhoea, nausea, vomiting, stomach ache or loss of appetite. If you get these, do not stop taking the tablets as these symptoms will normally go away in about 2 weeks. It helps if you take the tablets with or immediately after a meal.

Common (may affect up to 1 in 10 people)

  • Taste disturbance
  • Decreased or low vitamin B12 levels in the blood (symptoms may include extreme tiredness (fatigue), a sore and red tongue (glossitis), pins and needles (paraesthesia) or pale or yellow skin). Your doctor may arrange some tests to find out the cause of your symptoms because some of these may also be caused by diabetes or due to other unrelated health problems.

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

  • Skin rashes including redness, itching and hives

Reporting of side effects

If you get any side effects, talk to your doctor, pharmacist or nurse. 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 or search for MHRA Yellow Card in the Google Play or Apple App Store.

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

5. How to store Metformin Flamingo SR

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

Do not use this medicine after the expiry date which is stated on the pack after “EXP:”. The expiry date refers to the last day of that month.

This medicinal product does not require any special storage conditions.

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.

6. Contents of the pack and other information
What Metformin Flamingo SR contains
  • Each prolonged release tablet contains 500, 750 or 1000 milligrams of the active ingredient metformin hydrochloride.
  • The other ingredients are microcrystalline cellulose, hypromellose, colloidal silicon dioxide and sodium stearyl fumarate.

What Metformin Flamingo SR looks like and contents of the pack Metformin Flamingo SR500 mg prolonged release tablets are white to off white coloured, round shaped, biconvex tablets debossed with '500' on one side and plain on other side.

Metformin Flamingo SR750 mg prolonged release tablets are white to off white coloured, capsule shaped, biconvex tablets debossed with '750' on one side and plain on other side. Metformin Flamingo SR1000 mg prolonged release tablets are white to off white coloured, modified capsule shaped, biconvex tablets debossed with '1000' on one side and plain on other side. Metformin Flamingo SR are available in blister strips composed of PVC/PVDC-ALU

500mg: 20, 28, 30, 50, 56, 60, 84, 90, 100, 112, 120, 180, 600 tablets.

750 mg: 14, 20, 28, 30, 50, 56, 60, 84, 90, 100, 112, 120, 180 or 600 tablets.

1000 mg: 14, 20, 28, 30, 50, 56, 60, 84, 90, 100, 112, 120, 180 or 600 tablets.

Not all pack sizes may be marketed.

Marketing Authorization Holder
Flamingo Pharma (UK) Ltd.
First Floor
Kirkland House
11-15 Peterborough Road
Harrow
Middlesex
HA1 2AX
United Kingdom

Manufacturer
Flamingo Pharma (UK) Limited
The Bloc
38 Springfield Way
Anlaby, Hull
HU10 6RJ
United Kingdom

Product license number:

PL 43461/0170 / PL 43461/0171 / PL 43461/0172

This leaflet was last revised in 05/2025.

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Flamingo Pharma (UK) Ltd
Company image
Address
The BLOC, 38 Springfield Way, Kingston Upon Hull, HU10 6RJ, UK
Telephone
+44 (0) 7784240228
Medical Information Direct Line
+44 8000668348
Stock Availability
[email protected]