Metformin is a medicine used to treat type 2 diabetes. Diabetes is a long-term condition causing blood sugar to become too high.

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Metformin is a medicine used to treat type 2 diabetes. Diabetes is a long-term condition causing blood sugar to become too high.

    What is Metformin?

    Metformin is a medicine used to treat type-2 diabetes. It belongs to a group of medications called oral hypoglycemics, which work to reduce the level of sugar in the blood. They are used particularly in people who are overweight or obese, where changes in diet and exercise have not been enough to control their diabetes. Metformin can also be used in conjunction with other diabetes medications, such as with insulin or sulfonylureas.

    Metformin is a prescription only medication. You must have a prescription from a doctor in order to buy Metformin. However, it is possible for us to prescribe it to you following a brief online consultation. Contact us to find out more.

    Metformin can also be used to treat other conditions such as polycystic ovary syndrome. However, we only prescribe it to treat diabetes.

    The active ingredient in Metformin is metformin hydrochloride. It is sometimes known under the brand names Glucophage, Glumetza or Fortamet. For more information about Metformin, consult the patient information leaflet.

    How it works

    Metformin works by reducing the amount of glucose produced by your liver that is released into your bloodstream. It will also make muscle cells more sensitive to insulin, which encourages cells to absorb glucose from the bloodstream, decreasing blood glucose (blood sugar) level. It can also delay the absorption of glucose into the bloodstream after eating.

    Metformin is very effective in patients who are overweight, or those who have developed diabetes while pregnant.

    Before you take it

    You should not take Metformin if you are allergic to the active ingredient, metformin hydrochloride, or any of the other ingredients in the medication. A full list of ingredients can be found in the patient information leaflet. If you are allergic, you should consult with your doctor to discuss an alternative treatment for your diabetes.

    If you are suffering from a severe infection, or have recently suffered a severe injury, you should not take Metformin. Speak with your doctor to discuss a more suitable treatment for your condition.

    If you have a heart problem, such as heart failure, or you have been treated for a heart attack, do not take Metformin. Speak to your doctor to discuss an alternative medication for your diabetes.

    You should only take Metformin while pregnant or breastfeeding with the specific approval of your doctor.

    Metformin has the potential to cause a very rare, but extremely serious condition called lactic acidosis. This is of particular risk if your kidneys do not work properly or you have a condition whereby parts of your body have a reduced oxygen supply, such as acute heart disease or failure. You may also put yourself at risk of lactic acidosis if you fast for prolonged periods of time, or drink a large amount of alcohol.

    Symptoms of lactic acidosis can include vomiting, stomachache, a general feeling of being unwell, severe fatigue, or reduced body temperature. If you notice any of these symptoms while using Metformin, seek medical advice. Lactic acidosis is an emergency, and if left untreated can lead to a coma.

    While you are undergoing treatment with Metformin, your doctor will want to check your kidneys every 6 - 12 months to ensure they are functioning correctly. They may do this more often if you are elderly, or have worsening kidney function.

    If you require injection of a contrast medium such as iodine for a scan or X-ray, you must stop taking Metformin around the time of injection. Your doctor will tell you when you must stop taking Metformin and when you can start taking it again.

    Metformin may interact with certain other medications. You must not take Metformin without informing your doctor if you are taking any of the following:

    • Corticosteroid medication, such as asthma inhalers or nasal sprays
    • Beta-blockers, such as atenolol
    • Steroids such as prednisolone
    • Diuretic medication such as furosemide or bendroflumethiazide
    • Pain relief medication, especially NSAIDs such as ibuprofen or COX-2 inhibitors such as celecoxib
    • Blood pressure medication such as captopril or ramipril

    This is not an exhaustive list of warnings and interactions. For a full list, consult the patient information leaflet, or speak to your doctor.

    Dosage Instructions

    You must always take Metformin as prescribed by your doctor or pharmacist. Never exceed the stated dose. If you are in any way unsure of how to take it, please consult with your doctor or pharmacist for advice.

    The usual starting dose is either one 500mg or 850mg tablet, taken two or three times per day. Your doctor will tell you which dosage is right for you and how often to take it. Never take more than you have been told to take.

    If you have reduced kidney function or are elderly, your doctor will prescribe you a lower dose.

    Take your tablets with food. Swallow them whole, with plenty of water. Do not suck, crush or chew them.

    Store Metformin in a cool, dry place, free from heat and moisture. Keep it out of the reach of children and pets.

    Common Side Effects of Metformin

    Metformin may cause unwanted side effects. These are usually mild to moderate in nature, and should go away as your body becomes used to the medication. However, if they persist, or concern you, you may wish to see your doctor for advice. Side effects can include:

    • Stomachache
    • Loss of appetite
    • Nausea
    • Vomiting
    • Diarrhoea

    Metformin can also cause more serious side effects. These are rare, but you should visit your doctor if you experience them. Side effects may include:

    • Change in taste
    • Low vitamin B12 levels, which can lead to anaemia
    • Liver problems - abnormal liver function, jaundice or hepatitis
    • Unexplained weight gain or weight loss
    • Lactic acidosis (see “Before you take it”)

    Metformin may cause a serious allergic reaction in some patients. This is extremely rare, but an allergic reaction is an emergency. If you believe you are experiencing an allergic reaction, you must immediately seek medical help. Symptoms of an allergic reaction may include:

    • Swelling of the lips, tongue, mouth or throat
    • Hives or nettle rash
    • Trouble breathing or speaking
    • Skin rash - peeling, swelling, blistering or itching

    This is not an exhaustive list of side effects. For a full list, you should consult the patient information leaflet or see your doctor for advice.

    Frequently Asked Questions (FAQs)

    Is Metformin suitable for children?

    No. Metformin is suitable only for adults. Additionally, we do not prescribe any medication to anyone under 18 years of age.

    I’m pregnant. Can I take Metformin?

    You must consult your doctor before taking Metformin if you are pregnant or planning to become pregnant.

    What happens if I miss a dose?

    If you forget to take Metformin, you must take it as soon as you remember. However, if it is nearly time for your next dose, you should skip the missed dose and take your next dose as normal. Never double up to make up for a missed dose.

    What happens if I take too much?

    If you take too much Metformin, it is unlikely to cause significant harm, although you may experience unwanted or unpleasant side effects such as vomiting, stomach pain or severe fatigue. You should contact your doctor if you experience any of these side effects. It is extremely important that if you experience any of the symptoms of lactic acidosis (see “Before you take it”) after an overdose that you go to your local hospital casualty department immediately.

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