Glyburide and Metformin

Glyburide and metformin hydrochloride tablets is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. Glyburide and metformin hydrochloride tablets are a combination of glyburide, a sulfonylurea, and metformin hydrochloride (HCl), a biguanide, indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus.

Glyburide primarily lowers blood glucose by stimulating the release of insulin from the pancreas, an effect dependent upon functioning beta cells in the pancreatic islets. Sulfonylureas bind to the sulfonylurea receptor in the pancreatic beta-cell plasma membrane, leading to closure of the ATP-sensitive potassium channel, thereby stimulating the release of insulin. Metformin is an antihyperglycemic agent that improves glucose tolerance in patients with type 2 diabetes, 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 daylong plasma insulin response may decrease.

Adult Dosage: • Give glyburide and metformin hydrochloride tablets in divided doses, twice daily, with meals. • For patients not treated with either glyburide (or another sulfonylurea) or metformin HCl, initiate treatment with another formulation with a dose of 1.25 mg glyburide and 250mg metformin HCl orally, once or twice daily with meals. • For patients not adequately controlled on either glyburide (or another sulfonylurea) or metformin HCl alone, the recommended starting dose is 2.5 mg/500 mg or 5 mg/500 mg orally twice daily with meals. • For patients previously treated with a combination therapy of glyburide (or another sulfonylurea) and metformin HCl, the starting dose should not exceed the daily dose of glyburide (or equivalent dose of another sulfonylurea) and metformin HCl already being taken.

Glyburide and metformin hydrochloride tablets is contraindicated in patients with: • Severe renal impairment (eGFR below 30 mL/min/1.73 m 2 ). • Hypersensitivity to metformin or glyburide. • Acute or chronic metabolic acidosis, including diabetic ketoacidosis, with or without coma. • Concomitant administration of bosentan. • Severe renal impairment (eGFR below 30 mL/min/1.73 m 2 ). • Hypersensitivity to metformin or glyburide. • Acute or chronic metabolic acidosis, including diabetic ketoacidosis, with or without coma. • Concomitant administration of bosentan.

Boxed 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. • Lactic Acidosis: See boxed warning. • Hypoglycemia: May be severe. Ensure proper patient selection, dosing, and instructions, particularly in at-risk populations (e.g., elderly, renally impaired) and when used with other anti-diabetic medications. • Potential Increased Risk of Cardiovascular Mortality with Sulfonylureas: Inform patient of risks, benefits and treatment alternatives. • Hemolytic anemia: Can occur if glucose 6-phosphate dehydrogenase (G6PD) deficient. Consider a non-sulfonylurea alternative.

The following adverse reactions are also discussed elsewhere in the labeling: • Lactic Acidosis • Hypoglycemia • Cardiovascular mortality • Hemolytic anemia • Vitamin B 12 Deficiency Most common (>5%) adverse reactions to glyburide and metformin hydrochloride tablets diarrhea, headache, nausea/vomiting, abdominal pain, and dizziness.

Table 3 presents clinically significant drug interactions with glyburide and metformin hydrochloride. Table 3: Clinically Significant Drug Interactions with Glyburide and 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 glyburide and metformin hydrochloride may increase the risk for lactic acidosis. Intervention: Consider more frequent monitoring of these patients. Examples: Topiramate, zonisamide, acetazolamide and dichlorphenamide.

Store at temperatures up to 25°C (77°F).