Glucophage (Metformin) Oral Tablets
Glucophage is a prescription oral biguanide containing metformin, used as first-line therapy in adults with type 2 diabetes mellitus. Tablets are available at 500mg, 850mg and 1000mg, with an extended-release option.
- Active ingredients
- Metformin
- Manufacturer
- Merck Serono
- Dosage forms
- tablet, extended-release tablet
- Available dosages
- 500mg, 850mg, 1000mg
- Category
- Diabetes Treatment
What is it?
Glucophage is the original brand name for metformin, marketed by Merck Serono and approved decades ago in most major regulatory markets. It is one of the most widely prescribed oral antidiabetic medications worldwide and appears on the World Health Organization List of Essential Medicines. The product is supplied as immediate-release tablets and as extended-release tablets, with several fixed-dose combinations also available under different brand names.
Active ingredients
Each tablet contains metformin hydrochloride as the sole active ingredient at strengths of 500mg, 850mg or 1000mg. Metformin is a biguanide derived from galegine. It is highly soluble in water, has minimal plasma protein binding and is excreted unchanged by the kidneys, which explains why renal function is the main consideration in dosing.
Forms and dosages
Glucophage is administered orally with meals to improve gastrointestinal tolerance. According to the prescribing information, treatment usually starts at 500mg once or twice daily and is increased every one to two weeks based on tolerability and response, up to a typical maximum of 2000 to 3000mg per day in divided doses. The extended-release formulation supports once-daily evening dosing. Dose adjustment is needed for moderate to severe renal impairment.
Indications
The medication is indicated as first-line oral therapy in adults with type 2 diabetes mellitus, alone or in combination with other antidiabetic agents, including insulin. In selected paediatric populations and in some markets it is also used in adolescents from 10 years. Off-label or label-extension uses include polycystic ovary syndrome and prediabetes under specialist supervision. According to international guidelines, metformin should be considered at diagnosis in most adults with type 2 diabetes unless contraindicated.
How it works
Metformin reduces hepatic glucose production through inhibition of mitochondrial complex I, which raises the cellular AMP/ATP ratio and activates AMP-activated protein kinase. Secondary actions include modest improvement in peripheral insulin sensitivity and changes in gut microbiota and bile-acid signalling. The drug does not stimulate insulin secretion, which explains its low intrinsic risk of hypoglycaemia. Effects on weight are typically neutral or slightly favourable.
Frequently asked questions
How should Glucophage be taken? ▾
Glucophage is best taken with or after meals, divided across the day for the immediate-release formulation. According to the prescribing information, gradual dose escalation reduces gastrointestinal adverse effects. The extended-release formulation is usually taken once daily in the evening. Tablets are swallowed whole with water; extended-release tablets should not be crushed or chewed. Hydration is important, particularly during illness or hot weather.
Does Glucophage cause hypoglycaemia? ▾
Used alone, Glucophage carries a very low intrinsic risk of hypoglycaemia because it does not stimulate insulin secretion. Hypoglycaemia can still occur when Glucophage is combined with insulin or sulfonylureas, particularly during fasting, prolonged exercise or alcohol intake. According to the prescribing information, dose adjustment of insulin or secretagogues may be required when Glucophage is added or removed, under medical supervision.
What are the main gastrointestinal side effects? ▾
The most common adverse effects are nausea, diarrhoea, abdominal discomfort and metallic taste, especially during the first weeks. They tend to improve with time, gradual titration, taking the dose with food or switching to the extended-release formulation. Persistent or severe symptoms should prompt review with the prescriber. According to the prescribing information, very rare cases of lactic acidosis are mainly linked to renal impairment, hypoxia or other contributing conditions.
Does Glucophage need to be stopped before surgery or contrast? ▾
Yes, in defined situations. The prescribing information recommends temporary interruption around iodinated contrast administration and major surgery, particularly in patients with reduced renal function, to limit the risk of lactic acidosis. The medication is usually restarted after kidney function is reassessed. The exact protocol is set by the prescriber and the local hospital.
What are the main contraindications for Glucophage? ▾
Glucophage is contraindicated in severe renal impairment below specific eGFR thresholds defined in local labelling, in acute or chronic conditions that may cause tissue hypoxia such as decompensated heart failure, in hepatic failure, in acute alcohol intoxication and in known hypersensitivity to metformin. According to the prescribing information, treatment should be temporarily interrupted around iodinated contrast administration and major surgery.
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The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.