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metformin hydrochloride

METFORMIN HYDROCHLORIDE TABLETS

Standard Dose
2 DOSAGE AND ADMINISTRATION • 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 2,000 mg once daily with the evening meal ( 2.1 ) • Patients receiving metformin hydrochloride (HCl) tablets may be switched to metformin hydrochloride extended-release Renal Impairment: • Prior to initiation, assess renal function with estimated glomerular filtration rate (eGFR) ( 2.2 ) • Do not use in patients with eGFR below 30 mL/minute/1.73 m 2 ( 2.2 ) • Initiation is not recommended in patients with eGFR between 30 to 45 mL/minute/1.73 m 2 ( 2.2 ) • Assess risk/benefit of continuing if eGFR falls below 45 mL/minute/1.73 m 2 ( 2.2 ) • Discontinue if eGFR falls below 30 mL/minute/1.73 m 2 ( 2.2 ) 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 ( 2.3 ) 2.1 Adult Dosage and Administration • 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 2,000 mg once daily with the evening meal. • If glycemic control is not achieved with metformin hydrochloride extended-release tablets 2,000 mg once daily, consider a trial of metformin hydrochloride extended-release tablets 1,000 mg twice daily. • Patients receiving metformin hydrochloride (HCl) may be switched to metformin hydrochloride extended-release tablets once daily at the same total daily dose, up to 2,000 mg once daily. 2.2 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 Contraindications ( 4 ) and Warnings and Precautions ( 5.1 )]. 2.3 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.
Max Dose
See official label
Primary Use
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.
Summary

Indications and 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 biguanide indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. ( 1 ) Dosage and administration 2 DOSAGE AND ADMINISTRATION • 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 2,000 mg once daily with the evening meal ( 2.1 ) • Patients receiving metformin hydrochloride (HCl) tablets may be switched to metformin hydrochloride extended-release Renal Impairment: • Prior to initiation, assess renal function with estimated glomerular filtration rate (eGFR) ( 2.2 ) • Do not use in patients with eGFR below 30 mL/minute/1.73 m 2 ( 2.2 ) • Initiation is not recommended in patients with eGFR between 30 to 45 mL/minute/1.73 m 2 ( 2.2 ) • Assess risk/benefit of continuing if eGFR falls below 45 mL/minute/1.73 m 2 ( 2.2 ) • Discontinue if eGFR falls below 30 mL/minute/1.73 m 2 ( 2.2 ) 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 ( 2.3 ) 2.1 Adult Dosage and Administration • 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 2,000 mg once daily with the evening meal. • If glycemic control is not achieved with metformin hydrochloride extended-release tablets 2,000 mg once daily, consider a trial of metformin hydrochloride extended-release tablets 1,000 mg twice daily. • Patients receiving metformin hydrochloride (HCl) may be switched to metformin hydrochloride extended-release tablets once daily at the same total daily dose, up to 2,000 mg once daily. 2.2 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 Contraindications ( 4 ) and Warnings and Precautions ( 5.1 )]. 2.3 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.

Structured Monograph

Clinical summary

Indications and 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 biguanide indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. ( 1 ) Dosage and administration 2 DOSAGE AND ADMINISTRATION • 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 2,000 mg once daily with the evening meal ( 2.1 ) • Patients receiving metformin hydrochloride (HCl) tablets may be switched to metformin hydrochloride extended-release Renal Impairment: • Prior to initiation, assess renal function with estimated glomerular filtration rate (eGFR) ( 2.2 ) • Do not use in patients with eGFR below 30 mL/minute/1.73 m 2 ( 2.2 ) • Initiation is not recommended in patients with eGFR between 30 to 45 mL/minute/1.73 m 2 ( 2.2 ) • Assess risk/benefit of continuing if eGFR falls below 45 mL/minute/1.73 m 2 ( 2.2 ) • Discontinue if eGFR falls below 30 mL/minute/1.73 m 2 ( 2.2 ) 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 ( 2.3 ) 2.1 Adult Dosage and Administration • 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 2,000 mg once daily with the evening meal. • If glycemic control is not achieved with metformin hydrochloride extended-release tablets 2,000 mg once daily, consider a trial of metformin hydrochloride extended-release tablets 1,000 mg twice daily. • Patients receiving metformin hydrochloride (HCl) may be switched to metformin hydrochloride extended-release tablets once daily at the same total daily dose, up to 2,000 mg once daily. 2.2 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 Contraindications ( 4 ) and Warnings and Precautions ( 5.1 )]. 2.3 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. Warnings and cautions 5 WARNINGS AND PRECAUTIONS • Lactic Acidosis: See boxed warning. ( 5.1 ) • Vitamin B 12 Deficiency: Metformin may lower vitamin B 12 levels. Measure hematological parameters annually and vitamin B 12 at 2 to 3 year intervals and manage any abnormalities. ( 5.2 ) • 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. ( 5.3 ) 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. Metforminassociated 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

Boxed Warning

WARNING: LACTIC ACIDOSIS Post-marketing 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 characterized by elevated blood lactate levels (> 5 mmol/Liter), anion gap acidosis (without evidence of ketonuria or ketonemia), an increased lactate/pyruvate ratio; and metformin plasma levels generally >5 mcg/mL [see Warnings and Precautions (5.1) ]. Risk factors for metformin-associated lactic acidosis include renal impairment, concomitant use of certain drugs (e.g., carbonic anhydrase inhibitors such as topiramate), age 65 years old or greater, having a radiological study with contrast, surgery and other procedures, hypoxic states (e.g., acute congestive heart failure), excessive alcohol intake, and hepatic impairment. Steps to reduce the risk of and manage metformin-associated lactic acidosis in these high risk groups are provided [see Dosage and Administration (2.2) , Contraindications (4) , Warnings and Precautions (5.1) ]. If metformin-associated lactic acidosis is suspected, immediately discontinue metformin hydrochloride extended-release tablets and institute general supportive measures in a hospital setting. Prompt hemodialysis is recommended [see Warnings and Precautions (5.1) ]. WARNING: LACTIC ACIDOSIS See full prescribing information for complete boxed warning.

Monitoring

  • • 5 WARNINGS AND PRECAUTIONS • Lactic Acidosis: See boxed warning.
  • • ( 5.1 ) • Vitamin B 12 Deficiency: Metformin may lower vitamin B 12 levels.
  • • Measure hematological parameters annually and vitamin B 12 at 2 to 3 year intervals and manage any abnormalities.
  • • ( 5.2 ) • Hypoglycemia with Concomitant Use with Insulin and Insulin Secretagogues: Increased risk of hypoglycemia when used in combination with insulin and/or an insulin secretagogue.

Interaction Notes

  • • 7 DRUG INTERACTIONS Table 2 presents clinically significant drug interactions with metformin hydrochloride extended-release tablets.
  • • Table 2: 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.