Glyburide Metformin Drug Information

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.

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 hydrochloride (HCl), initiate treatment with another formulation of glyburide and metformin HCl at a starting 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 of glyburide and metformin hydrochloride tablets 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 of glyburide and metformin hydrochloride tablets should not exceed the daily dose of glyburide (or equivalent dose of another sulfonylurea) and metformin HCl already being taken. • Increase the dose gradually on the basis of glycemic control and tolerability, up to a maximum to a maximum dose of 20 mg glyburide/2,000 mg metformin HCl daily.

Patients Receiving Colesevelam •

Administer glyburide and metformin hydrochloride tablets at least 4 hours prior to colesevelam for patients taking both drugs concomitantly.

Recommendations for Use in Renal Impairment •

Assess renal function prior to initiation of glyburide and metformin hydrochloride tablets and periodically thereafter. • Glyburide and metformin hydrochloride tablets is contraindicated in patients with an estimated glomerular filtration rate (eGFR) below 30 mL/minute/1.73 m 2. • Initiation of glyburide and metformin hydrochloride tablets in patients with an eGFR between 30 to 45 mL/minute/1.73 m 2 is not recommended. • In patients taking glyburide and metformin hydrochloride tablets whose eGFR later falls below 45 mL/min/1.73 m 2, assess the benefit risk of continuing therapy. • Discontinue glyburide and metformin hydrochloride tablets if the patient’s eGFR later falls below 30 mL/minute/1.73 m 2.

Discontinuation for Iodinated Contrast Imaging Procedures •

Discontinue glyburide and metformin hydrochloride 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 glyburide and metformin hydrochloride tablets if renal function is stable.

Clinical Studies Experience

Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice. Adverse reactions are listed in Table 1. Table 1: Adverse Reactions Occurring >5% in Double-Blind Clinical Studies of Glyburide and Metformin Hydrochloride Used as Initial (20 Weeks) or Second-Line (14 Weeks) Therapy Hypoglycemia The incidence of reported symptoms of hypoglycemia (such as dizziness, shakiness, sweating, and hunger), in the initial therapy study of glyburide and metformin hydrochloride are summarized in Table 2.

As second-line therapy in patients inadequately controlled on sulfonylurea alone, approximately 6.8% of all patients treated with glyburide and metformin hydrochloride experienced hypoglycemic symptoms. Gastrointestinal Reactions The incidence of gastrointestinal (GI) side effects (diarrhea, nausea/vomiting, and abdominal pain) in the glyburide and metformin hydrochloride initial therapy study are summarized in Table 2. Across all glyburide and metformin hydrochloride studies, GI symptoms were the most common adverse events with glyburide and metformin hydrochloride and were more frequent at higher dose levels.

In controlled studies, <2% of patients discontinued glyburide and metformin hydrochloride therapy due to GI adverse events. Table 2: Hypoglycemia or Gastrointestinal Adverse Reactions in a Placebo and Active-Controlled Study of Glyburide and Metformin Hydrochloride as Initial Therapy (20 Weeks) Dermatologic Reactions Allergic skin reactions, e.g., pruritus, erythema, urticaria, and morbilliform or maculopapular eruptions, occur in 1.5% of glyburide-treated patients. These may be transient and may disappear despite continued use.

Postmarketing Adverse Reactions

The following adverse reactions have been identified during post-approval use of glyburide and metformin hydrochloride. 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. Allergic: Angioedema, arthralgia, myalgia, and vasculitis have been reported.

Dermatologic: Porphyria cutanea tarda and photosensitivity reactions have been reported with sulfonylureas. Hematologic: Leukopenia, agranulocytosis, thrombocytopenia, which occasionally may present as purpura, hemolytic anemia, aplastic anemia, and pancytopenia, have been reported with sulfonylureas. Hepatic: Cholestatic, hepatocellular, and mixed hepatocellular liver injury have been reported with postmarketing use of metformin.

Cholestatic jaundice and hepatitis may occur rarely with glyburide, which may progress to liver failure. Liver function abnormalities, including isolated transaminase elevations, have been reported. Metabolic: Hepatic porphyria reactions have been reported with sulfonylureas; however, these have not been reported with glyburide.

Disulfiram-like reactions have been reported very rarely with glyburide. Cases of hyponatremia have been reported with glyburide and all other sulfonylureas, most often in patients who are on other medications or have medical conditions known to cause hyponatremia or increase release of antidiuretic hormone. Other Reactions: Changes in accommodation and/or blurred vision have been reported with glyburide and other sulfonylureas.

These are thought to be related to fluctuation in glucose levels.

• Table 3 presents clinically significant drug interactions with glyburide and metformin hydrochloride. Table 3: Clinically Significant Drug Interactions with Glyburide and Metformin Hydrochloride 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 / multidrug and toxin extrusion inhibitors) could increase systemic exposure to metformin and may increase the risk for lactic acidosis.
• Carbonic anhydrase inhibitors may increase risk of lactic acidosis. Consider more frequent monitoring.
• 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.
• Alcohol can potentiate the effect of metformin on lactate metabolism. Warn patients against excessive alcohol intake.
• The hypoglycemic action of glyburide and metformin hydrochloride tablets may be potentiated by certain drugs.
• Concomitant administration of colesevalam may led to reduced glyburide absorption.

• 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.
• Concomitant administration of bosentan.

Glyburide Overdosage of sulfonylureas, including glyburide tablets, can produce hypoglycemia. Mild hypoglycemic symptoms, without loss of consciousness or neurological findings, should be treated with oral glucose. Severe hypoglycemic reactions with coma, seizure, or other neurological impairment are medical emergencies requiring immediate treatment.

The patient should be treated with glucagon or intravenous glucose. Patients should be closely monitored for a minimum of 24 to 48 hours since hypoglycemia may recur after apparent clinical recovery. Clearance of glyburide from plasma may be prolonged in persons with liver disease.

Because of the extensive protein binding of glyburide, dialysis is unlikely to be of benefit. Metformin Overdose of metformin has occurred, including ingestion of amounts greater than 50 g. Hypoglycemia was reported in approximately 10% of cases, but no causal association with metformin has been established.

Lactic acidosis has been reported in approximately 32% of metformin overdose cases. Metformin is dialyzable with a clearance of up to 170 mL/min under good hemodynamic conditions. Therefore, hemodialysis may be useful for removal of accumulated drug from patients in whom metformin overdosage is suspected.