Glucophage 500 mg, 850 mg and 1000 mg film-coated tablets – metformin for type 2 diabetes

Glucophage film-coated tablets contain metformin, a medicine from the biguanide group used to treat type 2 diabetes. Metformin helps to bring a raised blood glucose level down to normal values and does not cause hypoglycaemia on its own.

The medicine is used when diet and physical activity are not enough to control blood sugar, especially in overweight people. In overweight adults, long-term use also helps to lower the risk of diabetes complications and is associated with stable or moderately reduced body weight. In Serbia it is registered in three strengths: 500 mg, 850 mg and 1000 mg. Glucophage XR (prolonged-release tablets) is a separate medicine with a different way of taking it.

How does Glucophage lower blood sugar and how should it be taken correctly?

Key facts about the medicine

What is Glucophage used for?

According to the package leaflet, Glucophage is used to treat type 2 (“non-insulin-dependent”) diabetes when diet and physical activity alone are not enough, especially in overweight patients:

• adults can take it alone or together with other oral diabetes medicines or insulin;
• children aged 10 years and over and adolescents can take it alone or together with insulin;
• in overweight adults, long-term use also helps to reduce the risk of diabetes-related complications.

How is it taken and dosed?

Take the tablets during or after a meal, whole, with a glass of water – do not crush or chew them. One daily dose is taken with breakfast, two doses with breakfast and dinner, and three doses with breakfast, lunch and dinner. The medicine does not replace diet and regular physical activity.

• According to the Summary of Product Characteristics, two 500 mg tablets can be replaced by one 1000 mg tablet; the 1000 mg tablet can be divided into equal doses.
• Gradually increasing the dose improves stomach and bowel tolerability.
• The doctor regularly checks blood sugar and kidney function at least once a year (more often in the elderly and with reduced kidney function).

Special patient groups

• Children and adolescents: from 10 years; maximum 2000 mg daily. Experience in children aged 10–12 is limited, so the medicine is given only on special advice of the doctor. A child should take the medicine under the supervision of a parent.
• Elderly: more frequent checks of kidney function; the dose is adjusted to kidney function.
• Impaired kidney function: the dose is reduced according to GFR; with severe impairment (GFR below 30 mL/min) the medicine must not be taken.
• Liver disease: the medicine must not be taken.

Contraindications – when the medicine must not be used

Do not take Glucophage:

• if you are allergic to metformin or any of the excipients;
• if you have liver problems;
• if you have severely reduced kidney function;
• if you have uncontrolled diabetes (e.g. severe hyperglycaemia, nausea, vomiting, diarrhoea, rapid weight loss, lactic acidosis or ketoacidosis);
• if you are dehydrated (e.g. after long-lasting or severe diarrhoea or repeated vomiting);
• if you have a severe infection of the lungs, bronchi or kidneys;
• if you are being treated for acute heart failure, have recently had a heart attack, have severe circulation problems (shock) or breathing difficulties;
• if you drink alcohol excessively.

Warnings and precautions

• Lactic acidosis: stop the medicine temporarily and contact your doctor in conditions with fluid loss – vomiting, diarrhoea, fever, exposure to heat or if you drink less fluid than usual.
• Iodinated contrast agents and major surgery: the medicine is stopped before or at the time of the examination, and during and for some time after surgery; according to the SmPC it is restarted no sooner than 48 hours after imaging, once kidney function has been checked and found stable.
• Hypoglycaemia: Glucophage on its own does not lower blood sugar too much, but in combination with insulin, sulphonylureas or meglitinides there is a risk of hypoglycaemia (weakness, dizziness, sweating, fast heartbeat, vision problems, difficulty concentrating) – eating or drinking something containing sugar then helps.
• Vitamin B12: metformin can lower vitamin B12 levels in the blood; your doctor may carry out tests if you experience tiredness, a red and sore tongue, tingling or pale skin.

Interactions with other medicines, food and drink

Tell your doctor about all medicines you take. More frequent checks of blood sugar and kidney function or a dose adjustment may be needed, especially with:

• iodinated contrast agents (X-ray or CT examinations);
• diuretics;
• pain and anti-inflammatory medicines from the NSAID and COX-2 inhibitor groups (e.g. ibuprofen, celecoxib);
• ACE inhibitors and angiotensin II receptor antagonists (blood pressure medicines);
• beta-2 agonists (salbutamol, terbutaline) and corticosteroids;
• medicines that change the amount of metformin in the blood: verapamil, rifampicin, cimetidine, dolutegravir, ranolazine, trimethoprim, vandetanib, isavuconazole, crizotinib, olaparib;
• other diabetes medicines.

Avoid excessive alcohol intake – it increases the risk of lactic acidosis.

Pregnancy and breast-feeding

• Pregnancy: if you are pregnant, think you may be pregnant or are planning a pregnancy, talk to your doctor – they will decide whether your treatment or blood sugar monitoring needs to change.
• Breast-feeding: the medicine is not recommended while breast-feeding or if you plan to breast-feed.

Driving and using machines

Glucophage on its own does not cause hypoglycaemia and does not affect driving. With insulin, sulphonylureas or meglitinides be careful – do not drive if you feel symptoms of low blood sugar.

Possible side effects

• very common (more than 1 in 10): nausea, vomiting, diarrhoea, abdominal pain and loss of appetite – mostly at the start of treatment; dividing the dose and taking it with or straight after a meal helps. If the symptoms persist, stop the medicine and contact your doctor;
• common (up to 1 in 10): taste disturbance; reduced or low vitamin B12 level (according to the 2024 leaflet for 850 mg);
• very rare (up to 1 in 10,000): lactic acidosis; abnormal liver function tests or hepatitis (tiredness, loss of appetite and weight, with or without yellowing of the skin); redness, itching or hives.

In children and adolescents the nature and severity of side effects are similar to those in adults.

Overdose, missed dose and stopping treatment

• Overdose: may lead to lactic acidosis (vomiting, abdominal pain with cramps, general weakness, difficulty breathing, low body temperature, slow heartbeat) – stop the medicine immediately and go to the nearest hospital.
• Missed dose: do not take a double dose; take the next dose at the usual time.
• Stopping treatment: any change or stop of treatment is decided by the doctor.

Related information

For blood sugar self-monitoring in diabetes, see also the category Blood sugar meters – products in this category do not replace the medicine prescribed for you.

Composition, pack and manufacturer

• Active substance: metformin hydrochloride 500 mg, 850 mg or 1000 mg per film-coated tablet.
• Excipients (500 mg and 850 mg): povidone K30, magnesium stearate; film coating: hypromellose.
• Excipients (1000 mg): povidone K30, magnesium stearate; film coating: hypromellose, macrogol 400, macrogol 8000.
• Pack: PVC/Al blisters of 15 tablets; 500 mg – 30 or 60 tablets, 850 mg – 30 tablets, 1000 mg – 30 or 60 tablets.
• Marketing authorisation holder: Merck d.o.o. Belgrade, Omladinskih brigada 90v, Belgrade – Novi Beograd.

Storage

• This medicine does not require any special storage conditions.
• Keep out of the sight and reach of children.
• Do not use after the expiry date; return unused medicine to a pharmacy that collects unused medicines.

Frequently asked questions

Does Glucophage cause hypoglycaemia?

Not on its own. There is a risk of low blood sugar when it is taken together with insulin, sulphonylureas or meglitinides.

Why is Glucophage taken with a meal?

Taking it during or after a meal reduces nausea, diarrhoea and abdominal pain, which are very common at the start of treatment.

What is lactic acidosis and when is the risk higher?

It is a very rare but serious build-up of lactic acid in the blood. The risk is higher with reduced kidney function, dehydration, severe infections, fasting, excessive alcohol and liver disease. Signs are vomiting, abdominal pain, cramps, weakness and difficulty breathing – emergency help is then needed.

Do I have to stop Glucophage before a CT scan?

If an iodinated contrast agent is injected, the medicine is stopped before or at the time of the examination and restarted only after kidney function has been checked (no sooner than 48 hours). The exact plan is set by the doctor.

Sources

• ALIMS – Summary of Product Characteristics, Glucophage® 500 mg film-coated tablets (SmPC, Serbian)
• ALIMS – Package leaflet, Glucophage® 500/850/1000 mg (PIL, 500 mg authorisation, Serbian)
• ALIMS – Summary of Product Characteristics, Glucophage® 850 mg (SmPC, 2024, Serbian)
• ALIMS – Package leaflet, Glucophage® 850 mg (PIL, September 2024, Serbian)
• ALIMS – Summary of Product Characteristics, Glucophage® 1000 mg (SmPC, Serbian)
• ALIMS – Package leaflet, Glucophage® 500/850/1000 mg (PIL, 1000 mg authorisation, Serbian)

Date sources were checked: 25 October 2026.