Generic
Metformin Hydrochloride
187 brands available in the market
At a glance
Metformin Hydrochloride is used for type 2 diabetes mellitus and polycystic ovary syndrome (PCOS). It lowers glucose production in the liver, delays glucose absorption from the intestines, and increases insulin sensitivity.
Description
Metformin is a biguanide type oral antihyperglycemic drug used in the management of type 2 diabetes. It lowers both basal and postprandial plasma glucose. Its mechanism of action is different from sulfonylureas and it does not produce hypoglycemia. Metformin decreases hepatic glucose production, decreases intestinal absorption of glucose, and improves insulin sensitivity by increasing peripheral glucose uptake and utilization.
Indications
- Type 2 diabetes mellitus (especially in overweight patients) - monotherapy or in combination with other agents or insulin
- Polycystic ovary syndrome (PCOS)
Therapeutic class
Biguanides
Pharmacological class
Biguanide
Pharmacology
Metformin decreases hepatic glucose production by inhibiting gluconeogenesis and glycogenolysis, delays intestinal glucose absorption, and enhances insulin sensitivity by increasing peripheral glucose uptake and utilization.
Mechanism of action
Controls blood sugar by reducing hepatic glucose production, delaying intestinal glucose absorption, and increasing insulin sensitivity.
Dosage
Immediate Release (Adult):
- Initial: 500 mg twice daily or 850 mg once daily (with meals)
- Gradually increase by 500 mg weekly to max 2,000 mg/day; up to 2,550 mg/day if needed
Extended Release (Adult):
- Initial: 500 mg once daily (with evening meal)
- Increase by 500 mg weekly to max 2,000 mg/day
Children (10 years+): 500 mg twice daily; gradually increase to 2,000 mg/day
Administration
- Swallow tablet whole; do not chew, crush or break
- Take with food (to reduce stomach upset)
- Take at the same time each day
Missed dose
If you miss a dose, take it as soon as you remember; skip if it's almost time for next dose; do not double the dose.
Side effects
Common Side Effects:
- Nausea
- Vomiting
- Taste disturbance
- Diarrhea
- Abdominal pain
- Loss of appetite
- Decreased vitamin B12 absorption (long-term use)
Precautions & warnings
- Inform doctor if symptoms of lactic acidosis occur (deep/rapid breathing, persistent nausea, vomiting, abdominal pain)
- Monitor blood sugar regularly to avoid hypoglycemia
- Avoid alcohol (risk of lactic acidosis)
- Temporarily stop before major surgery or contrast dye procedures
- Monitor vitamin B12 levels
Contraindications
- eGFR <30 mL/min/1.73 m²
- Acute or chronic metabolic acidosis (including diabetic ketoacidosis)
- Severe renal or hepatic impairment
- Acute alcohol intoxication or alcoholism
- Pregnancy and lactation
Drug interactions
- Additive effect with sulfonylureas (hypoglycemia risk)
- Thiazide diuretics, corticosteroids, OCs may worsen glycemic control
- ACE inhibitors may reduce fasting blood glucose
- Cimetidine may increase serum levels
- Increased risk of lactic acidosis with iodinated contrast agents (potentially fatal)
Food interactions
Alcohol consumption with Metformin is unsafe.
Use in pregnancy
Use in Pregnancy: Metformin is generally considered safe during pregnancy (Category B); animal studies have shown low or no adverse effects. However, insulin is preferred during pregnancy.
Pregnancy Category: B — always consult a doctor before taking during pregnancy.
Use in lactation
Use in Lactation: Metformin is excreted in breast milk; no adverse effects observed in breastfed infants. However, limited data available, caution is advised.
Pediatric use
Pediatric dose established for children 10 years and older; particular caution for children aged 10-12 years.
Geriatric use
Elderly require dose adjustment due to potential decreased renal function; regular renal function assessment necessary.
Renal / hepatic impairment
Renal Impairment: eGFR <30: contraindicated; eGFR 30-45: not recommended to initiate; discontinue if eGFR falls below 30 during treatment.
Hepatic Impairment: Caution in liver disease; not recommended in severe liver disease.
Overdose effects
Overdose may cause lactic acidosis; hemodialysis is effective.
Storage conditions
Store below 30°C, away from light and moisture; keep out of reach of children.
Chemical structure
Metformin Hydrochloride