Metformin
Generic Name: Metformin Hydrochloride
Uses & Medical Indications
Improve glycemic control in adults and children with type 2 diabetes mellitus
Type 2 Diabetes Mellitus, Polycystic Ovary Syndrome (Off-label)
Work Mechanism & Pharmacology
Patient Overview of Work Mechanism
Metformin works by stopping the liver from overproducing unnecessary glucose and training muscle cells to utilize circulating sugar more effectively, without stressing the pancreas or causing low blood sugar crashes.
Clinical Mechanism of Action (MoA)
Biguanide antihyperglycemic agent that activates adenosine monophosphate-activated protein kinase (AMPK) in hepatocytes and skeletal myocytes. Suppresses hepatic gluconeogenesis through mild, transient inhibition of mitochondrial respiratory complex I, enhances peripheral glucose uptake and insulin-mediated GLUT4 transporter translocation, and slows intestinal glucose absorption.
Dosage & Administration Guidelines
500 mg orally twice a day or 850 mg orally once a day initially
500 mg orally twice a day (children 10-16 years)
Consider lower initial dose due to potential renal function decline
2550 mg/day (adults), 2000 mg/day (pediatrics)
Contraindicated if eGFR < 30 mL/min/1.73 m2. Dose adjustment required for eGFR 30-45.
Avoid use in patients with clinical or laboratory evidence of hepatic disease.
Side Effects & Safety Warnings
Diarrhea, nausea, vomiting, flatulence, asthenia, indigestion, abdominal discomfort
Lactic acidosis, Vitamin B12 deficiency, Hypoglycemia (when used with other antidiabetics)
Severe renal impairment, acute or chronic metabolic acidosis (including diabetic ketoacidosis)
Risk of lactic acidosis, especially in renal impairment, older age, or use of contrast dye.
Interactions (Drugs, Food & Alcohol)
Carbonic anhydrase inhibitors, drugs that reduce metformin clearance (e.g., ranolazine, dolutegravir)
Take with meals to reduce gastrointestinal side effects.
Avoid excessive alcohol intake as it increases the risk of lactic acidosis.
Identified Clinical Drug Interactions for Metformin:
Increased risk of contrast-induced nephropathy leading to severe Metformin-associated Lactic Acidosis (MALA).
Increased Metformin Exposure & Hemoconcentration
Pregnancy & Breastfeeding Safety
May be used during pregnancy if needed, but insulin is often preferred.
Present in human milk. Benefits must be weighed against potential risks to infant.
Patient Counseling & Practical Advice
Take with meals. Report symptoms of lactic acidosis immediately. Do not skip meals.
Take as soon as remembered. If it is almost time for the next dose, skip the missed dose. Do not double up.
Renal function (eGFR), HbA1c, fasting blood glucose, hematologic parameters (annually)
Frequently Asked Questions
When to Seek Urgent Medical Attention
Symptoms of Lactic Acidosis: Severe malaise, rapid deep breathing (Kussmaul breathing), severe somnolence, cold clammy extremities.
Content for Metformin was synthesized from standardized public health monographs, official pharmacopoeias, and health authorities:
- American Diabetes Association (ADA) — Standards of Medical Care in Diabetes - Pharmacologic Approaches
- European Association for the Study of Diabetes (EASD) — Consensus Guidelines on Metformin Therapy
The information provided on this website is for educational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare provider with any questions you may have regarding a medical condition.