Boxed Warning (Black Box)
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. Metformin-associated lactic acidosis was cha...
METFORMIN HYDROCHLORIDE
METFORMIN HYDROCHLORIDE
Manufacturer: Northwind Health Company, LLC
Clinical information
Indications & Usage
1 INDICATIONS AND USAGE Metformin hydrochloride extended-release tablets are indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. Metformin hydrochloride extended-release tablets are a biguanide indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. ( 1 )
Dosage & Administration
2 DOSAGE AND ADMINISTRATION Adult Dosage for Metformin Hydrochloride Extended-Release Tablets: Swallow metformin hydrochloride extended-release tablets whole and never crush, cut or chew (2.1 ) Starting dose: 500 mg orally once daily with the evening meal ( 2.1 ) Increase the dose in increments of 500 mg weekly, up to a maximum of 2000 mg once daily with the evening meal ( 2.1 ) Patients receiving metformin hydrochloride tablets may be switched to metformin hydrochloride extended-release tablets once daily at the same total daily dose, up to 2000 mg once daily ( 2.1 ) Renal Impairment: Prior to initiation, assess renal function with estimated glomerular filtration rate (eGFR) ( 2.3 ) Do not use in patients with eGFR below 30 mL/minute/1.73 m 2 ( 2.3 ) Initiation is not recommended in patients with eGFR between 30 to 45 mL/minute/1.73 m 2 ( 2.3 ) Assess risk/benefit of continuing if eGFR falls below 45 mL/ minute/1.73 m 2 ( 2.3) Discontinue if eGFR falls below 30 mL/minute/1.73 m 2 ( 2.3 ) Discontinuation for Iodinated Contrast Imaging Procedures: Metformin hydrochloride extended-release tablets may need to be discontinued at time of, or prior to, iodinated contrast imaging procedures ( 2.4 ) 2.1 Adult Dosage Metformin Hydrochloride Extended-Release Tablets: Swallow metformin hydrochloride extended-release tablets whole and never crush, cut or chew. The recommended starting dose of metformin hydrochloride extended-release tablets is 500 mg orally once daily with the evening meal. Increase the dose in increments of 500 mg weekly on the basis of glycemic control and tolerability, up to a maximum of 2000 mg once daily with the evening meal. If glycemic control is not achieved with metformin hydrochloride extended-release tablets 2000 mg once daily, consider a trial of metformin hydrochloride extended-release tablets 1000 mg twice daily. If higher doses are required, switch to metformin hydrochloride extended-release tablets at total daily doses up to 2550 mg administered in divided daily doses, as described above. Patients receiving metformin hydrochloride tablets may be switched to metformin hydrochloride extended-release tablets once daily at the same total daily dose, up to 2000 mg once daily. 2.3 Recommendations for Use in Renal Impairment Assess renal function prior to initiation of metformin hydrochloride extended-release tablets and periodically thereafter. Metformin hydrochloride extended-release tablets are contraindicated in patients with an estimated glomerular filtration rate (eGFR) below 30 mL/minute/1.73 m 2 . Initiation of metformin hydrochloride extended-release tablets in patients with an eGFR between 30 to 45 mL/minute/1.73 m 2 is not recommended. In patients taking metformin hydrochloride extended-release tablets whose eGFR later falls below 45 mL/min/1.73 m 2 , assess the benefit risk of continuing therapy. Discontinue metformin hydrochloride extended-release tablets if the patient's eGFR later falls below 30 mL/minute/1.73 m 2 [ see Warnings and Precautions (5.1) ]. 2.4 Discontinuation for Iodinated Contrast Imaging Procedures Discontinue metformin hydrochloride extended-release tablets at the time of, or prior to, an iodinated contrast imaging procedure in patients with an eGFR between 30 and 60 mL/min/1.73 m 2 ; in patients with a history of liver disease, alcoholism, or heart failure; or in patients who will be administered intra-arterial iodinated contrast. Re-evaluate eGFR 48 hours after the imaging procedure; restart metformin hydrochloride extended-release tablets if renal function is stable.
Contraindications
4 CONTRAINDICATIONS Metformin hydrochloride extended-release tablets are contraindicated in patients with: Severe renal impairment (eGFR below 30 mL/min/1.73 m 2 ) [ see Warnings and Precautions (5.1) ]. 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 ( 4 ) Acute or chronic metabolic acidosis, including diabetic ketoacidosis, with or without coma. ( 4 )
Safety
Adverse Reactions
6 ADVERSE REACTIONS The following adverse reactions are also discussed elsewhere in the labeling: Lactic Acidosis [ see Boxed Warning and Warnings and Precautions (5.1) ] Vitamin B 12 Deficiency [ see Warnings and Precautions (5.2) ] Hypoglycemia [ see Warnings and Precautions (5.3) ] For metformin hydrochloride extended-release tablets, the most common adverse reactions (>5.0%) are diarrhea, nausea/vomiting, flatulence, asthenia, indigestion, abdominal discomfort, and headache. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Ascend Laboratories, LLC at 1-877-ASCRX01 (877-272-7901) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 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 Extended-Release Tablets: In placebo-controlled trials, 781 patients were administered metformin hydrochloride extended-release tablets. Adverse reactions reported in greater than 5% of the metformin hydrochloride extended-release tablets patients, and that were more common in metformin hydrochloride extended-release tablets- than placebo-treated patients, are listed in Table 2. Table 2: Adverse Reactions from Clinical Trials of Metformin Hydrochloride Extended-Release Tablets Occurring >5% and More Common than Placebo in Patients with Type 2 Diabetes Mellitus Metformin Hydrochloride Extended-Release Tablets (n=781) Placebo (n=195) Diarrhea 10% 3% Nausea/Vomiting 7% 2% Diarrhea led to discontinuation of metformin hydrochloride extended-release tablets in 0.6% of patients. Additionally, the following adverse reactions were reported in ≥1.0% to ≤5.0% of metformin hydrochloride extended-release tablets patients and were more commonly reported with metformin hydrochloride extended-release tablets than placebo: abdominal pain, constipation, distention abdomen, dyspepsia/heartburn, flatulence, dizziness, headache, upper respiratory infection, taste disturbance. 6.2 Postmarketing Experience The following adverse reactions have been identified during post approval use of metformin. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Cholestatic, hepatocellular, and mixed hepatocellular liver injury have been reported with postmarketing use of metformin.
Drug Interactions
7 DRUG INTERACTIONS Table 3 presents clinically significant drug interactions with metformin hydrochloride extended-release tablets. Table 3: Clinically Significant Drug Interactions with metformin hydrochloride extended-release tablets 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 extended-release tablets may increase the risk for lactic acidosis. Intervention: Consider more frequent monitoring of these patients. Examples: Topiramate, zonisamide, acetazolamide or dichlorphenamide. Drugs that Reduce Metformin Hydrochloride Extended-Release Tablets Clearance Clinical Impact: Concomitant use of drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2] / multidrug and toxin extrusion [MATE] inhibitors) could increase systemic exposure to metformin and may increase the risk for lactic acidosis [see Clinical Pharmacology (12.3)]. Intervention: Consider the benefits and risks of concomitant use with metformin hydrochloride extended-release tablets. Examples: Ranolazine, vandetanib, dolutegravir, and cimetidine. Alcohol Clinical Impact: Alcohol is known to potentiate the effect of metformin on lactate metabolism. Intervention: Warn patients against excessive alcohol intake while receiving metformin hydrochloride extended-release tablets. Insulin Secretagogues or Insulin Clinical Impact: Coadministration of metformin hydrochloride extended-release tablets with an insulin secretagogue (e.g., sulfonylurea) or insulin may increase the risk of hypoglycemia. Intervention: Patients receiving an insulin secretagogue or insulin may require lower doses of the insulin secretagogue or insulin. Drugs Affecting Glycemic Control Clinical Impact: Certain drugs tend to produce hyperglycemia and may lead to loss of glycemic control. Intervention: When such drugs are administered to a patient receiving metformin hydrochloride extended-release tablets, observe the patient closely for loss of blood glucose control. When such drugs are withdrawn from a patient receiving metformin hydrochloride extended-release tablets, observe the patient closely for hypoglycemia. Examples: Thiazides and other diuretics, corticosteroids, phenothiazines, thyroid products, estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics, calcium channel blockers, and isoniazid. Carbonic anhydrase inhibitors may increase risk of lactic acidosis. Consider more frequent monitoring ( 7 ) Drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir, and cimetidine) may increase the accumulation of metformin. Consider the benefits and risks of concomitant use ( 7 ) Alcohol can potentiate the effect of metformin on lactate metabolism. Warn patients against excessive alcohol intake ( 7 )
Additional information
Description
11 DESCRIPTION Metformin hydrochloride extended-release 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 is a white to off-white crystalline compound with a molecular formula of C 4 H 11 N 5 • HCl and a molecular weight of 165.63. It is freely soluble in water and is practically insoluble in acetone, ether, and chloroform. The pK a of metformin is 12.4. The pH of a 1% aqueous solution of metformin hydrochloride is 6.68. Metformin hydrochloride extended-release tablets, USP contains 500 mg of metformin hydrochloride, which is equivalent to 389.93 mg metformin base. Metformin hydrochloride extended-release tablets USP, 500 mg contain the inactive ingredients carboxymethylcellulose sodium, hypromellose and magnesium stearate. Metformin Hydrochloride Extended-Release Tablets, USP meets USP Dissolution Test 3. Formula
How Supplied
16 HOW SUPPLIED/STORAGE AND HANDLING 16.1 How Supplied Table 13: Metformin Hydrochloride Extended-Release Tablets, USP Available Strengths, Units, and appearance Metformin Hydrochloride Extended-Release Tablets, USP 500 mg Bottles of 30 NDC 51655-559-52 White to off white capsule shaped, biconvex, beveled edge tablet, with occasionally mottled appearance, debossed with " 001" on one side and plain on other side. Bottles of 60 NDC 51655-559-25 Bottles of 90 NDC 51655-559-26 Bottles of 120 NDC 51655-559-82 Image 16.2 Storage Store at 20° to 25°C (68° to 77°F); excursions permitted to 15° to 30°C (59° to 86°F). [See USP Controlled Room Temperature.] Dispense in light-resistant containers.
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Frequently Asked Questions
What is metformin hydrochloride used for?+
Metformin hydrochloride is used to improve glycemic control in adults with type 2 diabetes mellitus. It is typically prescribed in conjunction with diet and exercise to help manage blood sugar levels. It is recommended to consult a doctor to determine the best course of treatment for your specific condition.
How does metformin hydrochloride work?+
Metformin hydrochloride works by decreasing glucose production in the liver, increasing insulin sensitivity, and thereby lowering blood sugar levels. It also helps to reduce the amount of glucose absorbed from food in the intestines. Consult a doctor to understand how metformin hydrochloride can work best for your individual needs.
What are the common side effects of metformin hydrochloride?+
Common side effects of metformin hydrochloride include nausea, vomiting, diarrhea, and stomach upset. In some cases, it can also cause more serious side effects such as lactic acidosis, which requires immediate medical attention. Consult a doctor if you experience any side effects while taking metformin hydrochloride.
Can I take metformin hydrochloride with other medications?+
Metformin hydrochloride can interact with other medications, including certain antibiotics, blood thinners, and diuretics. It is essential to inform your doctor about all the medications you are currently taking to avoid any potential interactions. Consult a doctor to ensure safe and effective use of metformin hydrochloride with other medications.
How long does it take for metformin hydrochloride to start working?+
Metformin hydrochloride typically starts working within a few days to a week after starting treatment, but it may take up to 2 weeks to reach its full effect. It is crucial to continue taking the medication as directed and to monitor your blood sugar levels regularly. Consult a doctor to discuss your treatment plan and to adjust the dosage if necessary.
MEDICAL DISCLAIMER
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