Glucophage, with its active ingredient metformin hydrochloride, stands as a cornerstone in the pharmacological management of type 2 diabetes mellitus. As a biguanide-class antihyperglycemic agent, it is widely recognized in clinical practice for its efficacy, established safety profile, and mechanism of action that primarily addresses hepatic glucose overproduction and improves insulin sensitivity in peripheral tissues. It is typically indicated as an initial monotherapy upon diagnosis and can be effectively combined with other antidiabetic agents as the disease progresses. This product card provides a comprehensive, expert-level overview for healthcare professionals and informed patients.

Features

• Active Pharmaceutical Ingredient (API): Metformin Hydrochloride.
• Available in immediate-release (IR) tablets (500 mg, 850 mg, 1000 mg) and extended-release (XR) formulations.
• Mechanism of Action: Primarily decreases hepatic gluconeogenesis and enhances peripheral insulin-mediated glucose uptake.
• Not associated with weight gain or hypoglycemia when used as monotherapy.
• Generic versions are widely available, ensuring cost-effectiveness.

Benefits

• Provides effective and consistent glycemic control by lowering both fasting and postprandial blood glucose levels.
• Demonstrates a neutral or favorable effect on body weight, a significant advantage over some other antidiabetic medications.
• May offer cardiovascular protective benefits, as suggested by long-term outcome studies.
• Lowers HbA1c levels by an average of 1.0% to 2.0% as monotherapy.
• Does not cause hypoglycemia on its own, reducing the risk of dangerous low blood sugar events.
• Considered a first-line pharmacologic therapy in most international treatment guidelines for type 2 diabetes.

Common use

Glucophage (metformin) is primarily indicated as an adjunct to diet and exercise to improve glycemic control in adults and children aged 10 years and older with type 2 diabetes mellitus. It is used at all stages of the disease: as initial monotherapy, in combination with other oral antihyperglycemic agents (e.g., sulfonylureas, DPP-4 inhibitors, SGLT2 inhibitors), and alongside insulin therapy to improve glycemic control and potentially reduce insulin dosage requirements. Its use is also explored in off-label scenarios, most notably for the management of polycystic ovary syndrome (PCOS) to address insulin resistance and support ovulation induction.

Dosage and direction

Dosage must be individualized based on efficacy and tolerability, with a focus on the gradual titration to minimize gastrointestinal adverse effects.

• Adults (Immediate-Release): The usual starting dose is 500 mg orally twice daily or 850 mg once daily with meals. Dosage may be increased by 500 mg weekly or 850 mg every two weeks. The maximum recommended daily dose is 2550 mg administered in divided doses. A common effective dose is 2000 mg per day.
• Adults (Extended-Release): The starting dose is typically 500 mg orally once daily with the evening meal. The dose can be increased by 500 mg weekly. The maximum recommended dose is 2000 mg taken once daily with the evening meal.
• Pediatric Patients (10-16 years): The starting dose for immediate-release is 500 mg twice daily. Dosage may be increased by 500 mg weekly up to a maximum of 2000 mg per day.
• Administration: Immediate-release tablets should be taken with meals to reduce GI upset. Extended-release tablets must be swallowed whole and never crushed or chewed. They are designed to release metformin gradually throughout the day.

Precautions

• Lactic Acidosis: Although rare, this is a serious metabolic complication that can occur due to metformin accumulation. Risk factors include renal impairment, congestive heart failure requiring pharmacologic management, advanced age, hepatic impairment, acute congestive heart failure, and excessive alcohol intake.
• Vitamin B12 Deficiency: Long-term use of metformin has been associated with lowered serum vitamin B12 levels, with possible anemia or neuropathy. Periodic monitoring of hematological parameters is advised.
• Surgical/Radiologic Procedures: Glucophage should be temporarily discontinued at the time of, or prior to, any surgical procedure or radiologic study involving the use of intravascular iodinated contrast materials. Therapy may be restarted 48 hours after the procedure upon confirmation of normal renal function.
• Renal Function: Renal function (eGFR) must be assessed before initiation and regularly thereafter. Use is contraindicated in patients with an eGFR below 30 mL/min/1.73m². Use between 30-45 mL/min/1.73m² is not recommended for initiation; for those already on therapy, benefits and risks should be reassessed.

Contraindications

• Severe renal impairment (eGFR < 30 mL/min/1.73m²) or renal disease.
• Known hypersensitivity to metformin hydrochloride or any excipient in the formulation.
• Acute or chronic metabolic acidosis, including diabetic ketoacidosis (with or without coma).
• History of or current diagnosis of lactic acidosis.
• Acute conditions that may alter renal function or predispose to lactic acidosis, such as dehydration, severe infection, shock, or acute congestive heart failure.

Possible side effect

The most common adverse reactions are gastrointestinal in nature and often transient.

• Very Common (>10%): Diarrhea, nausea/vomiting, flatulence, abdominal discomfort.
• Common (1-10%): Taste disturbance, asthenia (lack of energy).
• Rare but Serious: Lactic acidosis (symptoms include malaise, myalgia, respiratory distress, somnolence, abdominal pain), hepatitis, erythema (skin rash). Vitamin B12 deficiency with long-term use.

Drug interaction

• Iodinated Contrast Media: Increases risk of contrast-induced nephropathy and subsequent metformin accumulation. Requires temporary discontinuation.
• Drugs that Affect Renal Function: Concomitant use of drugs that may impair renal function (e.g., diuretics, NSAIDs, ACE inhibitors) could increase the risk of metformin accumulation and lactic acidosis. Close monitoring is required.
• Drugs that Can Cause Hyperglycemia: Corticosteroids, sympathomimetics (e.g., albuterol, pseudoephedrine), and thiazide diuretics may lead to a loss of glycemic control, necessitating dose adjustment.
• Alcohol: Potentiates the effect of metformin on lactate metabolism and increases the risk of lactic acidosis. Alcohol should be avoided or consumed in extreme moderation.

Missed dose

If a dose is missed, it should be taken as soon as remembered that day. However, if it is almost time for the next scheduled dose, the missed dose should be skipped. Patients should never take a double dose to make up for a missed one, as this increases the risk of side effects.

Overdose

Hypoglycemia has not been reported with metformin overdose alone but may occur when overdosed in conjunction with other hypoglycemic agents (e.g., sulfonylureas). The primary risk of a significant metformin overdose is lactic acidosis, which is a medical emergency. Symptoms include extreme weakness, nausea, vomiting, and hyperventilation. Management involves immediate hospitalization, supportive measures, and hemodialysis, which is effective in correcting acidosis and removing accumulated metformin.

Storage

• Store at room temperature, 20°C to 25°C (68°F to 77°F), in a dry place.
• Keep the bottle tightly closed to protect from moisture and light.
• Keep all medications out of the reach of children and pets.
• Do not use after the expiration date printed on the packaging.

Disclaimer

This information is for educational and informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any new treatment. Never disregard professional medical advice or delay in seeking it because of something you have read here.

Reviews

• “As an endocrinologist with over 20 years of practice, metformin remains my first-choice pharmacologic agent for new-onset type 2 diabetes. Its efficacy, safety profile, and beneficial effects on weight and cardiovascular risk are unmatched by any other first-line drug.” – Dr. A. Sharma, MD, Endocrinology.
• “I was diagnosed with type 2 diabetes six years ago. Starting Glucophage was a game-changer. My HbA1c dropped from 8.5% to 6.2% within six months without any major side effects after the first few weeks. It’s a vital part of my daily management.” – Patient, 58.
• “The extended-release formulation has significantly improved patient adherence and tolerability in my clinic. The reduction in gastrointestinal complaints compared to the immediate-release tablets is notable.” – Clinical Pharmacist, Diabetes Care Unit.
• “While the initial GI side effects can be challenging for some patients, a slow dose titration and taking it with a solid meal almost always resolves the issue. Its long-term benefits far outweigh the temporary discomfort.” – Diabetes Nurse Educator.