API

Metformin hydrochloride

Drug classification

Biguanide class; oral antihyperglycemic agent for type 2 diabetes mellitus management.

Dosage form

Tablet

API strength per dosage

Metformine HCl 500mg

Dose

Metformin HCl 500 mg is typically started at 500 mg once or twice daily with meals in adults; dose may be gradually increased based on glycemic response. Maximum recommended daily dose is 2000–2550 mg. Use in children ≥10 years is similar. Contraindicated in severe renal or hepatic impairment; dose adjustment or avoidance is required.

Mechanism of action

Metformin inhibits hepatic gluconeogenesis primarily by activating AMP-activated protein kinase (AMPK), decreases intestinal glucose absorption, and increases peripheral glucose uptake and utilization by improving insulin sensitivity, resulting in reduced blood glucose levels without stimulating insulin secretion.

Indications

Type 2 diabetes mellitus, particularly in overweight patients when diet and exercise alone do not provide adequate glycemic control; may be used as monotherapy or in combination with other oral antidiabetic agents or insulin.

Side effects

Gastrointestinal disturbances (nausea, vomiting, diarrhea, abdominal pain, loss of appetite), metallic taste, vitamin B12 deficiency with long-term use, lactic acidosis (rare but serious), weight loss or stabilization.

Pregnancy category

Metformin is not associated with increased risk of fetal malformations; use in pregnancy may be considered when benefits outweigh potential risks. Consult healthcare provider.

Precautions

Renal function assessment, risk of lactic acidosis, monitor vitamin B12 levels with long-term use, avoid in severe hepatic impairment, caution with alcohol use, assess for gastrointestinal intolerance, review for contraindicated medications, monitor glycemic control, temporarily discontinue before iodinated contrast procedures.

Contraindications

Hypersensitivity to metformin, severe renal impairment, acute or chronic metabolic acidosis (including diabetic ketoacidosis), conditions predisposing to hypoxemia or lactic acidosis, severe hepatic impairment, acute alcohol intoxication, dehydration, shock.