Combinations of oral blood glucose lowering drugs

Metformin Hydrochloride

Approved 12 Mar 2012OralTablet

The FDA lists this product in 60 strengths and forms.

Boxed warningThe FDA label of this medicine carries a boxed warning, the strongest warning the FDA gives. Read it under warnings and precautions.

Indications

Metformin Hydrochloride Tablets, USP 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 Tablet 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. (1)

Contraindications

Metformin Hydrochloride 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)

Warnings and precautions

5.1Lactic 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.

Indications

Contraindications

(4)

Warnings and precautions

5.1Lactic Acidosis

Interactions

Table 2 presents clinically significant drug interactions with metformin hydrochloride tablets. Table 2: Clinically Significant Drug Interactions with Metformin Hydrochloride 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 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 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 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 tablets. Insulin Secretagogues or Insulin Clinical Impact: Coadministration of metformin hydrochloride 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 metformin hydrochloride tablets, observe the patient closely for loss of blood glucose control.

When such drugs are withdrawn from a patient receiving metformin hydrochloride 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)

Pregnancy and breastfeeding

8.1 Pregnancy

8.1Pregnancy Risk Summary

Limited data with metformin hydrochloride tablets in pregnant women are not sufficient to determine a drug-associated risk for major birth defects or miscarriage. Published studies with metformin use during pregnancy have not reported a clear association with metformin and major birth defect or miscarriage risk [see Data]. There are risks to the mother and fetus associated with poorly controlled diabetes mellitus in pregnancy [see Clinical Considerations].

No adverse developmental effects were observed when metformin was administered to pregnant Sprague Dawley rats and rabbits during the period of organogenesis at doses up to 2- and 5 times, respectively, a 2550 mg clinical dose, based on body surface area [see Data]. The estimated background risk of major birth defects is 6–10% in women with pre-gestational diabetes mellitus with an HbA1C >7 and has been reported to be as high as 20–25% in women with a HbA1C >10.

The estimated background risk of miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2–4% and 15–20%, respectively. Clinical Considerations Disease-associated maternal and/or embryo/fetal risk Poorly-controlled diabetes mellitus in pregnancy increases the maternal risk for diabetic ketoacidosis, pre-eclampsia, spontaneous abortions, preterm delivery, stillbirth and delivery complications.

Poorly controlled diabetes mellitus increases the fetal risk for major birth defects, stillbirth, and macrosomia related morbidity. Data Human Data Published data from post-marketing studies have not reported a clear association with metformin and major birth defects, miscarriage, or adverse maternal or fetal outcomes when metformin was used during pregnancy. However, these studies cannot definitely establish the absence of any metformin-associated risk because of methodological limitations, including small sample size and inconsistent comparator groups.

Animal Data Metformin hydrochloride did not adversely affect development outcomes when administered to pregnant rats and rabbits at doses up to 600 mg/kg/day. This represents an exposure of about 2 and 5 times a 2550 mg clinical dose based on body surface area comparisons for rats and rabbits, respectively. Determination of fetal concentrations demonstrated a partial placental barrier to metformin.

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)]

6.1Clinical 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 Tablets In a U.S. clinical trial of metformin hydrochloride tablets in patients with type 2 diabetes mellitus, a total of 141 patients received metformin hydrochloride tablets up to 2550 mg per day.

Adverse reactions reported in greater than 5% of metformin hydrochloride tablets treated patients and that were more common than in placebo-treated patients, are listed in Table 1. Table 1: Adverse Reactions from Clinical Trial of Metformin Hydrochloride Tablets Occurring >5% and More Common than Placebo in Patients with Type 2 Diabetes Mellitus Metformin Hydrochloride Tablet (n=141) Placebo (n=145) Diarrhea 53% 12% Nausea/Vomiting 26% 8% Flatulence 12% 6% Asthenia 9% 6% Indigestion 7% 4% Abdominal Discomfort 6% 5% Headache 6% 5% Diarrhea led to discontinuation of metformin hydrochloride tablets in 6% of patients.

Additionally, the following adverse reactions were reported in ≥1% to ≤5.0% of metformin hydrochloride tablets treated patients and were more commonly reported with metformin hydrochloride tablets than placebo: abnormal stools, hypoglycemia, myalgia, lightheaded, dyspnea, nail disorder, rash, sweating increased, taste disorder, chest discomfort, chills, flu syndrome, flushing, palpitation. In metformin hydrochloride tablets clinical trials of 29-week duration, a decrease to subnormal levels of previously normal serum vitamin B 12 levels was observed in approximately 7% of patients.

Pediatric Patients In clinical trials with metformin hydrochloride tablets in pediatric patients with type 2 diabetes mellitus, the profile of adverse reactions was similar to that observed in adults.

6.2Postmarketing 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. ForMetformin Hydrochloride 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 Time-Cap Labs al 1-877-376-4271 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch

Metformin Hydrochloride

Indications

Contraindications

Warnings and precautions

5.1Lactic Acidosis

Two medicines in one question?

Metformin Hydrochloride

Indications

Contraindications

Warnings and precautions

5.1Lactic Acidosis

Two medicines in one question?

5.2Vitamin B 12 Deficiency

5.3Hypoglycemia with Concomitant Use with Insulin and Insulin Secretagogues Insulin

Interactions

Pregnancy and breastfeeding

8.1Pregnancy Risk Summary

Adverse reactions

6.1Clinical Studies Experience

6.2Postmarketing Experience

Composition

Strengths and forms

Official product information

At a glance

Guidelines