Metformin Hcl

Generic Name: metformin hcl

Over-the-Counter (OTC)

Brand Names:

Metformin Hcl

Metformin hydrochloride tablets, USP contain the antihyperglycemic agent metformin, which is a biguanide, in the form of monohydrochloride. The chemical name of metformin hydrochloride is N,N-dimethylimidodicarbonimidic diamide hydrochloride. The structural formula is as shown below: Metformin hydrochloride, USP is a white to off-white crystalline compound with a molecular formula of C4H11N5 • HCl and a molecular weight of 165.63.

Overview

Metformin hydrochloride tablets, USP contain the antihyperglycemic agent metformin, which is a biguanide, in the form of monohydrochloride. The chemical name of metformin hydrochloride is N,N-dimethylimidodicarbonimidic diamide hydrochloride. The structural formula is as shown below: Metformin hydrochloride, USP is a white to off-white crystalline compound with a molecular formula of C4H11N5 • HCl and a molecular weight of 165.63.

Uses

Metformin hydrochloride tablets, USP are 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.

Dosage

2.1 Adult Dosage Metformin Hydrochloride Tablets The recommended starting dose of metformin hydrochloride tablets is 500 mg orally twice a day or 850 mg once a day, given with meals. Increase the dose in increments of 500 mg weekly or 850 mg every 2 weeks on the basis of glycemic control and tolerability, up to a maximum dose of 2,550 mg per day, given in divided doses. Doses above 2,000 mg may be better tolerated given 3 times a day with meals. 2.2 Pediatric Dosage for Metformin Hydrochloride Tablets The recommended starting dose of metformin hydrochloride tablets for pediatric patients 10 years of age and older is 500 mg orally twice a day, given with meals.

Side Effects

The following adverse reactions are also discussed elsewhere in the labeling: Lactic Acidosis [see Boxed Warning and Warnings and Precautions (5.1)] Vitamin B12 Deficiency [see Warnings and Precautions (5.2)] Hypoglycemia [see Warnings and Precautions (5.3)] 6.1 Clinical Studies Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Metformin Hydrochloride In a U.S. clinical trial of metformin hydrochloride in patients with type 2 diabetes mellitus, a total of 141 patients received metformin hydrochloride up to 2,550 mg per day.

Interactions

Table 3 presents clinically significant drug interactions with metformin hydrochloride. Table 3: Clinically Significant Drug Interactions with Metformin Hydrochloride Carbonic Anhydrase Inhibitors Clinical Impact: Carbonic anhydrase inhibitors frequently cause a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. Concomitant use of these drugs with metformin hydrochloride may increase the risk for lactic acidosis. Intervention: Consider more frequent monitoring of these patients. Examples: Topiramate, zonisamide, acetazolamide or dichlorphenamide.

Warnings

WARNING: LACTIC ACIDOSIS Postmarketing cases of metformin-associated lactic acidosis have resulted in death, hypothermia, hypotension, and resistant bradyarrhythmias. The onset of metformin-associated lactic acidosis is often subtle, accompanied only by nonspecific symptoms such as malaise, myalgias, respiratory distress, somnolence, and abdominal pain. 5.1 Lactic Acidosis There have been postmarketing cases of metformin-associated lactic acidosis, including fatal cases. These cases had a subtle onset and were accompanied by nonspecific symptoms such as malaise, myalgias, abdominal pain, respiratory distress, or increased somnolence; however, hypotension and resistant bradyarrhythmias have occurred with severe acidosis. Metformin-associated lactic acidosis was characterized by elevated blood lactate concentrations (>5 mmol/L), anion gap acidosis (without evidence of ketonuria or ketonemia), and an increased lactate: pyruvate ratio; metformin plasma levels were generally >5 mcg/mL. Metformin decreases liver uptake of lactate increasing lactate blood levels which may increase the risk of lactic acidosis, especially in patients at risk. Metformin hydrochloride tablets are contraindicated in patients with: Severe renal impairment (eGFR below 30 mL/min/1.73 m2) [see Warnings and Precautions (5.1)]. Hypersensitivity to metformin. Acute or chronic metabolic acidosis, including diabetic ketoacidosis, with or without coma.

Storage

Store at 20° to 25°C (68° to 77°F); excursions permitted between 15° to 30°C (59° to 86°F) [See USP Controlled Room Temperature]. Dispense in light-resistant containers.

Frequently Asked Questions

What is Metformin Hcl used for?

Metformin hydrochloride tablets, USP are 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.

What are the side effects of Metformin Hcl?

The following adverse reactions are also discussed elsewhere in the labeling: Lactic Acidosis [see Boxed Warning and Warnings and Precautions (5.1)] Vitamin B12 Deficiency [see Warnings and Precautions (5.2)] Hypoglycemia [see Warnings and Precautions (5.3)] 6.1 Clinical Studies Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Metformin Hydrochloride In a U.S. clinical trial of metformin hydrochloride in patients with type 2 diabetes mellitus, a total of 141 patients received metformin hydrochloride up to 2,550 mg per day.

What are the important warnings for Metformin Hcl?

WARNING: LACTIC ACIDOSIS Postmarketing cases of metformin-associated lactic acidosis have resulted in death, hypothermia, hypotension, and resistant bradyarrhythmias. The onset of metformin-associated lactic acidosis is often subtle, accompanied only by nonspecific symptoms such as malaise, myalgias, respiratory distress, somnolence, and abdominal pain. 5.1 Lactic Acidosis There have been postmarketing cases of metformin-associated lactic acidosis, including fatal cases. These cases had a subtle onset and were accompanied by nonspecific symptoms such as malaise, myalgias, abdominal pain, respiratory distress, or increased somnolence; however, hypotension and resistant bradyarrhythmias have occurred with severe acidosis. Metformin-associated lactic acidosis was characterized by elevated blood lactate concentrations (>5 mmol/L), anion gap acidosis (without evidence of ketonuria or ketonemia), and an increased lactate: pyruvate ratio; metformin plasma levels were generally >5 mcg/mL. Metformin decreases liver uptake of lactate increasing lactate blood levels which may increase the risk of lactic acidosis, especially in patients at risk. Metformin hydrochloride tablets are contraindicated in patients with: Severe renal impairment (eGFR below 30 mL/min/1.73 m2) [see Warnings and Precautions (5.1)]. Hypersensitivity to metformin. Acute or chronic metabolic acidosis, including diabetic ketoacidosis, with or without coma.

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Medical Disclaimer

This drug information is for educational purposes only and should not replace professional medical advice. Drug information is sourced from the FDA National Drug Code Directory and Structured Product Labeling. Always consult with a healthcare provider before starting, stopping, or changing any medication.