Glucophage® 500 mg
Film – coated tablet
Please read this carefully in full before taking this medicine.
Each film-coated tablet of Glucophage 500 mg contains as active ingredient 500 mg metformin hydrochloride (equivalent to 390 mg metformin base).
Povidone K30, magnesium stearate and hypromellose.
Glucophage 500 mg tablets are white, circular, convex and film-coated.
Merck S.L. Poligono Merck,
08100 Mollet Del Valles (Barcelona), Spain.
Glucophage is used for the treatment of type 2 diabetes as an adjunct to adequate diet and exercise. In adults, Glucophage may be given alone or with oral antidiabetic agents, or with insulin. In children from 10 years old and adolescents, Glucophage may be given alone or with insulin.
Glucophage must not be used in the following cases:
• hypersensitivity to metformin hydrochloride or any of the ingredients,
• severe destabilisation of diabetes with either pre-coma or ketoacidosis (a condition caused by substances called ‘ketone bodies’ accumulating in the blood; symptoms include stomach pain, fast and deep breathing, sleepiness or unusual fruity odour of the breath),
• renal insufficiency, even if moderate (impairment of kidney function with increased blood creatinine levels or decreased creatinine clearance < 60 ml/mn,
• infectious diseases (for example respiratory tract infection, urinary tract infection),
• X-ray examination involving the use of iodinated contrast media (for example intravenous urography, angiography), see section ‘Special warnings and precautions’,
• elective major surgery, see section ‘Special warnings and precautions’,
• disease which may cause tissue hypoxia (heart failure, recent myocardial infarction, respiratory insufficiency, shock)
• hepatic insufficiency (impaired liver function),
• dehydration (for example due to persistent or severe diarrhoea, recurrent vomiting),
• excessive consumption of alcoholic beverages,
Special warnings and precautions
Symptoms of lactic acidosis are vomiting, abdominal pain with muscle cramps, a general feeling, of not being well with severe fatigue and difficulty in breathing.
If these symptoms occur, patients must stop taking Glucophage immediately and consult their doctor straight away.
Lactic acidosis can occur due to metformin accumulation, especially in diabetic patients with significant renal insufficiency. Other associated risk factors are poorly controlled diabetes, ketosis, prolonged fasting, alcoholism, hepatic insufficiency and any condition associated with hypoxia. Lactic acidosis is a medical emergency and must be treated in a hospital. The most effective way to remove lactate and metformin from the blood is haemodialysis.
Since metformin (active ingredient in Glucophage) is excreted mainly by the kidneys, your kidney function (creatinine clearance and/or serum creatinine levels) must be determined before treatment initiation and regularly thereafter:
– at least annually in patients with normal kidney function
– at least two to four times a year in patients with creatinine clearance at the lower limit of normal and in elderly patients. Special caution should be exercised in situations where kidney function may become impaired, for example in the elderly or when initiating antihypertensive treatment or diuretic treatment or treatment with a non-steroidal anti-inflammatory medicine (NSAID).
lodinated contrast media
If a patient is scheduled to undergo X-ray examinations involving the use of iodinated contrast media, such as intravenous urography or angiography, treatment with Glucophage must be discontinued 48 hours before the test or at the time of the test. Glucophage may not be reinstituted until 48 hours afterwards, and only after kidney function has been tested and found to be normal.
If a patient is going to have an elective major surgery, treatment with Glucophage must be discontinued 48 hours before the surgery. Glucophage will not be re-instituted until 48 hours after the surgery, and only after ensuring that kidney function is normal.
Children and adolescents
The diagnosis of type 2 diabetes should be confirmed before treatment with Glucophage is initiated.
A follow-up of the effect of Glucophage on growth and puberty especially in pre-pubescent children is recommended.
• All patients should continue following any dietary advice the doctor has given including some energy-restricted diet for overweight patients. Patients should also get some regular exercise.
• The usual laboratory tests for diabetes monitoring should be performed regularly.
• Avoid consumption of alcoholic beverages.
• Patients have to inform their doctor of any other treatment they are receiving and of any infectious illnesses such as influenza, respiratory tract infection or urinary tract infection.
Pregnancy and lactation
• Glucophage is not the appropriate treatment of type 2 diabets during pregnancy. Women who are pregnant or plan to become pregnant have to consult their doctor for replacement of Glucophage by insulin.
• Glucophage is not recommended during breast-feeding.
As a general rule, women who are pregnant or breast-feeding should always ask their doctor for advice before taking a medicine.
Effect on ability to drive and use machines
When used alone, Glucophage does not cause hypoglycaemia. Consequently, there is no particular risk when driving or using machines. However, caution is advised if certain antidiabetic medicines are taken together with Glucophage, such as sulphonylurea, insulin, glinide or other hypoglycaemic agents. Symptoms of hypoglycaemia include weakness, dizziness, increased sweating, fast heart beating, vision disorders or difficulty in concentration. When you start to feel these symptoms, you should not drive or use machines.
While taking Glucophage, patients must not use Iodinated contrast agents (see section ‘Contraindications’).
Special precautions may be required if patients take Glucophage and any of the following medicines at the same time:
– corticosteroids, tetracosactides, beta2 agonists such as salbutamol or terbutaline, diuretics, danazol or chlorpromazine increase glycaemia. Blood glucose monitoring is recommended and dose adjustment of Glucophage should be considered.
– antihypertensive agents of the angiotensin-converting enzyme inhibitors class may have an hypoglycaemic action. If necessary, the dosage of Glucophage should be adjusted.
– diuretics (especially loop diuretics) may increase the risk of lactic acidosis. Kidney function monitoring is recommended.
– alcohol containing medicines. Alcohol increases the risk of lactic acidosis, especially in case of fasting or malnutrition or hepatic insufficiency.
As a general rule, patients have to consult their doctor or pharmacist, if they are taking or have recently taken another medicine, including over-the-counter medicines.
Dosage and administration
The dosage of Glucophage is determined by the doctor on an individual basis according to the results of laboratory blood glucose measurement.
1 tablet of Glucophage 500 mg once daily in children from 10 years old and adolescents.
1 tablet of Glucophage 500 mg 2 or 3 times daily in adults.
In case Glucophage is used in combination with insulin, the usual starting dose is also 1 tablet once daily for children from 10 years old and adolescents and 1 tablet 2 to 3 times daily in adults, while insulin dosage is adjusted on the basis of blood glucose measurements.
After 10 to 15 days, the dose may be slowly increased by increment one tablet depending on blood glucose measurements.
Maximum daily dose
2 g daily in children, taken as 2 or 3 divided doses.
3 g daily in adults, taken as 3 divided doses.
Elderly and decreased renal function
In elderly and in patients with decreased renal function, the dosage should be adjusted based on renal function.
Method and route of administration Oral route
Swallow the tablets without chewing during or at the end of the meals. This will avoid the patient having gastrointestinal discomfort
(see section ‘adverse effects’). For example, for a dosage of two tablets daily, take 1 tablet with breakfast and 1 tablet with evening meal.
IN ALL CASES YOU SHOULD STRICTLY COMPLY WITH YOUR DOCTOR’S PRESCRIPTION.
Duration of treatment . .
Glucophage must be taken daily without interruption. In case you stop the treatment you must contact your doctor.
If you have forgotten to take a Glucophage: Take the next dose at the usual time. Do not double the dose of Glucophage.
If you have taken more Glucophage than indicated: Consult your doctor or pharmacist immediately. High overdose or concomitant risks may lead to lactic acidosis. Lactic acidosis is a medical emergency and must be treated in hospital. The most effective method to remove lactate and metformin is haemodialysis.
Like all medicines, Glucophage can cause adverse effects although not everybody gets them.
The following adverse effects were observed in clinical studies or in routine patient management. They are presented by frequencies which are defined as follows: very common: ≥10%; common ≥1%, <l0%; uncommon: ≥0.1%, <1.0%; rare ≥0.01%, <0.l%; very rare <0.01%; isolated cases.
Very common: Gastrointestinal discomfort such as nausea, vomiting, diarrhoea, abdominal pain and loss of appetite may occur especially at the beginning of treatment. These symptoms are generally transient and can be reduced by taking Glucophage with meals. If symptoms persist, the patients should stop taking the treatment and consult their doctor.
Common: Taste disturbance.
• Lactic acidosis is a very serious complication, which results in vomiting, abdominal pain with muscle cramps and/or a general feeling of malaise with severe fatigue and which requires specific treatment. If this occurs, patients should stop taking Glucophage immediately and consult their doctor promptly. Lactic acidosis is a medical emergency and must be treated in a hospital.
• Skin reactions such as erythema (red skin), itching or urticaria (eruption with itching).
• Decreased vitamin B12 levels (to take into consideration if the patient is suffering from megaloblastic anaemia).
Isolated cases: liver function tests abnormalities or hepatitis resolving upon Glucophage discontinuation.
REPORT ANY UNDESIRABLE OR DISTRESSING EFFECT TO YOUR DOCTOR OR PHARMACIST. To prevent serious reactions, speak to your doctor immediately, if an undesirable effect is severe, occurred suddenly or gets worse rapidly.
Store in a cool dry place.
Do not use after the expiry date shown on the outer packaging.
KEEP OUT OF THE REACH AND SIGHT OF CHILDREN: Parents and caregivers are advised to oversee treatment in children.
Date of last revision of this leaflet: March 2011
This medicine has been prescribed by your doctor for the treatment of diabetes, a disease characterized by hyperglycaemia, i.e. an excess of glucose in the blood. Glucose appears in the urine only when it exceeds a certain level in the blood.
There are two types of diabetes:
• the most common type (type 2) can be treated by medicines taken by the oral route (oral antihabetics),
• the other type (type 1) requires the administration of insulin injections.
It is essential that medical tests be performed to determine the type of diabetes, as insulin injections and oral antidiabetics cannot b freely interchanged.
• in all cases, strictly adhere to the diet and exercise recommended by your doctor,
• carry a card or bracelet saying you are diabetic,
• visit your doctor regularly.