Metformin Hydrochloride

What it is and how it works

Mechanism of Action Metformin is an antihyperglycemic agent which improves glucose tolerance in patients with type 2 diabetes mellitus, lowering both basal and postprandial plasma glucose. Metformin decreases hepatic glucose production, decreases intestinal absorption of glucose, and improves insulin sensitivity by increasing peripheral glucose uptake and utilization. With metformin therapy, insulin secretion remains unchanged while fasting insulin levels and day-long plasma insulin response may decrease.

Indications

Metformin hydrochloride tablets is indicated as an adjunct to diet and exercise to improve glycemic control in adults and pediatric patients 10 years of age and older with type 2 diabetes mellitus. Metformin hydrochloride extended-release tablets is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. Metformin is a biguanide indicated as an adjunct to diet and exercise to improve glycemic control in adults and pediatric patients 10 years of age and older with type 2 diabetes mellitus. Metformin is a biguanide indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus.

Dosage and administration (summary)

Adult Dosage for Metformin Hydrochloride Tablets: Starting dose: 500 mg orally twice a day or 850 mg once a day, with meals Increase the dose in increments of 500 mg weekly or 850 mg every 2 weeks, up to a maximum dose of 2550 mg per day, given in divided doses Doses above 2000 mg may be better tolerated given 3 times a day with meals Adult Dosage for Metformin Hydrochloride Extented-Release Tablets: Swallow metformin hydrochloride extended-release tablets whole and never crush, cut or chew Starting dose: 500 mg orally once daily with the evening meal Increase the dose in increments of 500 mg weekly, up to a maximum of 2000 mg once daily with the evening meal Patients receiving metformin hyd…

Contraindications

Metformin hydrochloride tablets and metformin hydrochloride extended-release tablets are contraindicated in patients with: Severe renal impairment (eGFR below 30 mL/min/1.73 m2) . Hypersensitivity to metformin. Acute or chronic metabolic acidosis, including diabetic ketoacidosis, with or without coma. Severe renal impairment (eGFR below 30 mL/min/1.73 m 2 ) ( 4 , 5.1 ) Hypersensitivity to metformin Acute or chronic metabolic acidosis, including diabetic ketoacidosis, with or without coma.

Warnings and precautions

Lactic Acidosis: See boxed warning. Vitamin B12 Deficiency: Metformin may lower vitamin B12 levels. Measure hematological parameters annually and vitamin B12 at 2 to 3 year intervals and manage any abnormalities. Hypoglycemia with Concomitant Use with Insulin and Insulin Secretagogues: Increased risk of hypoglycemia when used in combination with insulin and/or an insulin secretagogue. Lower dose of insulin or insulin secretagogue may be required Lactic Acidosis There have been postmarketing cases of metformin-associated lactic acidosis, including fatal cases.

Pregnancy

Pregnancy Risk Summary Limited data with metformin hydrochloride tablets and metformin hydrochloride extended-release tablets in pregnant women are not sufficient to determine a drug-associated risk for major birth defects or miscarriage.

Storage and supply

HOW SUPPLIED Table 13: Metformin Hydrochloride Tablets, USP and Metformin Hydrochloride Extended-Release Tablets, USP Available Strengths, Units, and Appearance Metformin Hydrochloride Tablets, USP 500 mg Bottles of 100 NDC 67877-217-01 Metformin hydrochloride tablets, USP 500 mg are white to off-white, round shape, biconvex coated tablets debossed…

Source: Metformin Hydrochloride (Metformin Hydrochloride) — US FDA prescribing information, 2025-12-18, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.