Glyburide

MICRONASE is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus.

Hypoglycemia

See PRECAUTIONS and OVERDOSE Sections.

Gastrointestinal Reactions

Cholestatic jaundice and hepatitis may occur rarely which may progress to liver failure; MICRONASE Tablets should be discontinued if this occurs.

Liver function abnormalities, including isolated transaminase elevations, have been reported.

Gastrointestinal disturbances, eg, nausea, epigastric fullness, and heartburn are the most common reactions, having occurred in 1.8% of treated patients during clinical trials. They tend to be dose related and may disappear when dosage is reduced.

Dermatologic Reactions

Allergic skin reactions, eg, pruritus, erythema, urticaria, and morbilliform or maculopapular eruptions occurred in 1.5% of treated patients during clinical trials. These may be transient and may disappear despite continued use of MICRONASE; if skin reactions persist, the drug should be discontinued.

Porphyria cutanea tarda and photosensitivity reactions have been reported with sulfonylureas.

Hematologic Reactions

Leukopenia, agranulocytosis, thrombocytopenia, hemolytic anemia (see PRECAUTIONS), aplastic anemia, and pancytopenia have been reported with sulfonylureas.

Metabolic Reactions

Hepatic porphyria and disulfiram-like reactions have been reported with sulfonylureas; however, hepatic porphyria has not been reported with MICRONASE and disulfiram-like reactions have been reported very rarely.

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. The syndrome of inappropriate antidiuretic hormone (SIADH) secretion has been reported with certain other sulfonylureas, and it has been suggested that these sulfonylureas may augment the peripheral (antidiuretic) action of ADH and/or increase release of ADH.

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.

In addition to dermatologic reactions, allergic reactions such as angioedema, arthralgia, myalgia and vasculitis have been reported.

The administration of oral hypoglycemic drugs has been reported to be associated with increased cardiovascular mortality as compared to treatment with diet alone or diet plus insulin. This warning is based on the study conducted by the University Group Diabetes Program (UGDP), a long-term prospective clinical trial designed to evaluate the effectiveness of glucose-lowering drugs in preventing or delaying vascular complications in patients with non-insulin-dependent diabetes. The study involved 823 patients who were randomly assigned to one of four treatment groups

UGDP reported that patients treated for 5 to 8 years with diet plus a fixed dose of tolbutamide (1.5 grams per day) had a rate of cardiovascular mortality approximately 2½ times that of patients treated with diet alone. A significant increase in total mortality was not observed, but the use of tolbutamide was discontinued based on the increase in cardiovascular mortality, thus limiting the opportunity for the study to show an increase in overall mortality. Despite controversy regarding the interpretation of these results, the findings of the UGDP study provide an adequate basis for this warning. The patient should be informed of the potential risks and advantages of MICRONASE and of alternative modes of therapy.

Although only one drug in the sulfonylurea class (tolbutamide) was included in this study, it is prudent from a safety standpoint to consider that this warning may also apply to other oral hypoglycemic drugs in this class, in view of their close similarities in mode of action and chemical structure.

Take this medication exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The dose your doctor recommends may be based on the following:

• other medical conditions you have
• other medications you are taking
• how you respond to this medication
• age

There is no fixed dose range for glyburide for the management of type 2 diabetes. Blood sugar levels should be monitored and the dose of glyburide adjusted based on response. Glyburide should be started at a low dose (1.25 to 2.5 mg daily) and increased slowly.

If you take too much glyburide, call your healthcare provider or local Poison Control Center or seek emergency medical attention right away.

If glyburide is administered by a healthcare provider in a medical setting, it is unlikely that an overdose will occur. However, if overdose is suspected, seek emergency medical attention.

Absorption

Bioavailability

Almost completely absorbed following oral administration.4 23 24 94

Onset

Hypoglycemic action generally begins within 45–60 minutes and is maximal within 1.5–3 hours.4 27 32 49

Duration

In nonfasting diabetic patients, the hypoglycemic action may persist for up to 24 hours.1 2 33

Food

Food does not affect rate or extent of absorption.27 28 94

Special Populations

In patients with renal1 2 27 or hepatic1 2 impairment, serum concentrations may be increased.

Distribution

Extent

Distributed in substantial amounts into bile.1 2 3 25 26 36

Appears to cross the placenta.81 101 Not known if distributed into breast milk.1 2

Plasma Protein Binding

>99% (for glyburide).7 25 37

>97% (for major metabolite 4-trans-hydroxyglyburide).25

Elimination

Metabolism

Appears to be completely metabolized, 25 26 31 36 probably in the liver.31

Elimination Route

Excreted as metabolites in urine and feces in approximately equal proportions.1 2 23 25 26 30 31 47

Minimally removed by hemodialysis.42

Half-life

1.4–1.8 hours (for glyburide)24 27 29 41 97 or approximately 10 hours (for glyburide and metabolites).25 30 31 32

Special Populations

In patients with severe renal impairment, clearance may be decreased and half-life prolonged.42 43

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

• If your symptoms or health problems do not get better or if they become worse, call your doctor.
• Do not share your drugs with others and do not take anyone else's drugs.
• Keep a list of all your drugs (prescription, natural products, vitamins, OTC) with you. Give this list to your doctor.
• Talk with the doctor before starting any new drug, including prescription or OTC, natural products, or vitamins.
• Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about this medicine, please talk with your doctor, nurse, pharmacist, or other health care provider.
• If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

This information should not be used to decide whether or not to take glyburide or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to glyburide. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.

Review Date: October 4, 2017

• Antidiabetic Agent, Sulfonylurea

Ajmaline: Sulfonamides may enhance the adverse/toxic effect of Ajmaline. Specifically, the risk for cholestasis may be increased. Monitor therapy

Alcohol (Ethyl): Sulfonylureas may enhance the adverse/toxic effect of Alcohol (Ethyl). A flushing reaction may occur. Monitor therapy

Alpha-Lipoic Acid: May enhance the hypoglycemic effect of Antidiabetic Agents. Monitor therapy

Aminolevulinic Acid (Systemic): Photosensitizing Agents may enhance the photosensitizing effect of Aminolevulinic Acid (Systemic). Avoid combination

Aminolevulinic Acid (Topical): Photosensitizing Agents may enhance the photosensitizing effect of Aminolevulinic Acid (Topical). Monitor therapy

Amodiaquine: CYP2C8 Inhibitors may increase the serum concentration of Amodiaquine. Avoid combination

Androgens: May enhance the hypoglycemic effect of Blood Glucose Lowering Agents. Exceptions: Danazol. Monitor therapy

Antidiabetic Agents: May enhance the hypoglycemic effect of Hypoglycemia-Associated Agents. Monitor therapy

Antidiabetic Agents (Thiazolidinedione): May enhance the hypoglycemic effect of Sulfonylureas. Management: Consider sulfonylurea dose adjustments in patients taking thiazolidinediones and monitor for hypoglycemia. Consider therapy modification

Beta-Blockers: May enhance the hypoglycemic effect of Sulfonylureas. Cardioselective beta-blockers (eg, acebutolol, atenolol, metoprolol, and penbutolol) may be safer than nonselective beta-blockers. All beta-blockers appear to mask tachycardia as an initial symptom of hypoglycemia. Ophthalmic beta-blockers are probably associated with lower risk than systemic agents. Exceptions: Levobunolol; Metipranolol. Monitor therapy

Bosentan: GlyBURIDE may enhance the hepatotoxic effect of Bosentan. GlyBURIDE may increase the metabolism of Bosentan. Bosentan may increase the metabolism of GlyBURIDE. Avoid combination

Carbocisteine: Sulfonylureas may enhance the adverse/toxic effect of Carbocisteine. Specifically, sulfonylureas may enhance adverse effects of alcohol that is present in liquid formulations of carbocisteine-containing products. Monitor therapy

Ceritinib: May increase the serum concentration of CYP2C9 Substrates. Management: Concurrent use of ceritinib with a CYP2C9 substrate that has a narrow therapeutic index (e.g., warfarin, phenytoin) should be avoided when possible. Monitor therapy

Chloramphenicol: May decrease the metabolism of Sulfonylureas. Monitor therapy

Cimetidine: May increase the serum concentration of Sulfonylureas. Monitor therapy

Clarithromycin: May increase the serum concentration of GlyBURIDE. Monitor therapy

Colesevelam: May decrease the serum concentration of GlyBURIDE. Management: Administer glyburide at least 4 hours prior to colesevelam. Consider therapy modification

Cyclic Antidepressants: May enhance the hypoglycemic effect of Sulfonylureas. Monitor therapy

CycloSPORINE (Systemic): May diminish the therapeutic effect of GlyBURIDE. GlyBURIDE may increase the serum concentration of CycloSPORINE (Systemic). Monitor therapy

CYP2C9 Inducers (Strong): May increase the metabolism of CYP2C9 Substrates. Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Consider therapy modification

CYP2C9 Inhibitors (Moderate): May decrease the metabolism of CYP2C9 Substrates. Monitor therapy

CYP2C9 Inhibitors (Strong): May decrease the metabolism of CYP2C9 Substrates. Consider therapy modification

Dabrafenib: May decrease the serum concentration of CYP2C9 Substrates. Management: Seek alternatives to the CYP2C9 substrate when possible. If concomitant therapy cannot be avoided, monitor clinical effects of the substrate closely (particularly therapeutic effects). Consider therapy modification

Dexketoprofen: May enhance the adverse/toxic effect of Sulfonamides. Monitor therapy

DPP-IV Inhibitors: May enhance the hypoglycemic effect of Sulfonylureas. Management: Consider a decrease in sulfonylurea dose when initiating therapy with a dipeptidyl peptidase-IV inhibitor and monitor patients for hypoglycemia. Consider therapy modification

Enzalutamide: May decrease the serum concentration of CYP2C9 Substrates. Management: Concurrent use of enzalutamide with CYP2C9 substrates that have a narrow therapeutic index should be avoided. Use of enzalutamide and any other CYP2C9 substrate should be performed with caution and close monitoring. Consider therapy modification

Fibric Acid Derivatives: May enhance the hypoglycemic effect of Sulfonylureas. Monitor therapy

Fluconazole: May increase the serum concentration of Sulfonylureas. Management: Seek alternatives when possible. If used together, monitor closely for increased effects of sulfonylureas if fluconazole is initiated/dose increased, or decreased effects if fluconazole is discontinued/dose decreased. Consider therapy modification

GLP-1 Agonists: May enhance the hypoglycemic effect of Sulfonylureas. Management: Consider sulfonylurea dose reductions when used in combination with glucagon-like peptide-1 agonists. Avoid the use of lixisenatide in patients receiving both basal insulin and a sulfonylurea. Consider therapy modification

Guanethidine: May enhance the hypoglycemic effect of Antidiabetic Agents. Monitor therapy

Herbs (Hypoglycemic Properties): May enhance the hypoglycemic effect of Hypoglycemia-Associated Agents. Monitor therapy

Hyperglycemia-Associated Agents: May diminish the therapeutic effect of Antidiabetic Agents. Monitor therapy

Hypoglycemia-Associated Agents: May enhance the hypoglycemic effect of other Hypoglycemia-Associated Agents. Monitor therapy

Hypoglycemia-Associated Agents: Antidiabetic Agents may enhance the hypoglycemic effect of Hypoglycemia-Associated Agents. Monitor therapy

Lumacaftor: May decrease the serum concentration of CYP2C9 Substrates. Lumacaftor may increase the serum concentration of CYP2C9 Substrates. Monitor therapy

MAO Inhibitors: May enhance the hypoglycemic effect of Blood Glucose Lowering Agents. Monitor therapy

Mecamylamine: Sulfonamides may enhance the adverse/toxic effect of Mecamylamine. Avoid combination

Metreleptin: May enhance the hypoglycemic effect of Sulfonylureas. Management: Sulfonylurea dosage adjustments (including potentially large decreases) may be required to minimize the risk for hypoglycemia with concurrent use of metreleptin. Monitor closely. Consider therapy modification

Miconazole (Oral): May enhance the hypoglycemic effect of Sulfonylureas. Miconazole (Oral) may increase the serum concentration of Sulfonylureas. Monitor therapy

MiFEPRIStone: May increase the serum concentration of CYP2C9 Substrates. Management: Use CYP2C9 substrates at the lowest recommended dose, and monitor closely for adverse effects, during and in the 2 weeks following mifepristone treatment. Consider therapy modification

Mitiglinide: May enhance the adverse/toxic effect of Sulfonylureas. Avoid combination

Pegvisomant: May enhance the hypoglycemic effect of Blood Glucose Lowering Agents. Monitor therapy

Porfimer: Photosensitizing Agents may enhance the photosensitizing effect of Porfimer. Monitor therapy

Probenecid: May decrease the protein binding of Sulfonylureas. Probenecid may increase the serum concentration of Sulfonylureas. Monitor therapy

Prothionamide: May enhance the hypoglycemic effect of Blood Glucose Lowering Agents. Monitor therapy

Quinolone Antibiotics: May enhance the hypoglycemic effect of Blood Glucose Lowering Agents. Quinolone Antibiotics may diminish the therapeutic effect of Blood Glucose Lowering Agents. Specifically, if an agent is being used to treat diabetes, loss of blood sugar control may occur with quinolone use. Monitor therapy

RaNITIdine: May increase the serum concentration of Sulfonylureas. Monitor therapy

RifAMPin: May decrease the serum concentration of Sulfonylureas. Management: Seek alternatives to these combinations when possible. Monitor closely for diminished therapeutic effects of sulfonylureas if rifampin is initiated/dose increased, or enhanced effects if rifampin is discontinued/dose decreased. Consider therapy modification

Salicylates: May enhance the hypoglycemic effect of Blood Glucose Lowering Agents. Monitor therapy

Selective Serotonin Reuptake Inhibitors: May enhance the hypoglycemic effect of Blood Glucose Lowering Agents. Monitor therapy

SGLT2 Inhibitors: May enhance the hypoglycemic effect of Sulfonylureas. Management: Consider a decrease in sulfonylurea dose when initiating therapy with a sodium-glucose cotransporter 2 inhibitor and monitor patients for hypoglycemia. Consider therapy modification

Sulfonamide Derivatives: May enhance the hypoglycemic effect of Sulfonylureas. Monitor therapy

Thiazide and Thiazide-Like Diuretics: May diminish the therapeutic effect of Antidiabetic Agents. Monitor therapy

Verteporfin: Photosensitizing Agents may enhance the photosensitizing effect of Verteporfin. Monitor therapy

Vitamin K Antagonists (eg, warfarin): Sulfonylureas may enhance the anticoagulant effect of Vitamin K Antagonists. Vitamin K Antagonists may enhance the hypoglycemic effect of Sulfonylureas. Monitor therapy

Voriconazole: May increase the serum concentration of Sulfonylureas. Monitor therapy

Concerns related to adverse reactions:

• Cardiovascular mortality: Product labeling states oral hypoglycemic drugs may be associated with an increased cardiovascular mortality as compared to treatment with diet alone or diet plus insulin. Data to support this association are limited, and several studies, including a large prospective trial (UKPDS) have not supported an association.

• Hypoglycemia: All sulfonylurea drugs are capable of producing severe hypoglycemia. Hypoglycemia is more likely to occur when caloric intake is deficient, after severe or prolonged exercise, when ethanol is ingested, or when more than one glucose-lowering drug is used. It is also more likely in elderly patients, malnourished or debilitated patients, and in patients with severe renal and hepatic impairment, adrenal and/or pituitary insufficiency; use with caution.

• Sulfonamide (“sulfa”) allergy: The FDA-approved product labeling for many medications containing a sulfonamide chemical group includes a broad contraindication in patients with a prior allergic reaction to sulfonamides. There is a potential for cross-reactivity between members of a specific class (eg, two antibiotic sulfonamides). However, concerns for cross-reactivity have previously extended to all compounds containing the sulfonamide structure (SO2NH2). An expanded understanding of allergic mechanisms indicates cross-reactivity between antibiotic sulfonamides and nonantibiotic sulfonamides may not occur or at the very least this potential is extremely low (Brackett 2004; Johnson 2005; Slatore 2004; Tornero 2004). In particular, mechanisms of cross-reaction due to antibody production (anaphylaxis) are unlikely to occur with nonantibiotic sulfonamides. T-cell-mediated (type IV) reactions (eg, maculopapular rash) are less well understood and it is not possible to completely exclude this potential based on current insights. In cases where prior reactions were severe (Stevens-Johnson syndrome/TEN), some clinicians choose to avoid exposure to these classes.

Disease-related concerns:

• Glucose-6-phosphate dehydrogenase deficiency: Patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency may be at an increased risk of sulfonylurea-induced hemolytic anemia; however, cases have also been described in patients without G6PD deficiency during postmarketing surveillance. Use with caution and consider a nonsulfonylurea alternative in patients with G6PD deficiency.

• Renal impairment: Use caution in advanced renal insufficiency due to accumulation of active metabolites (Snyder 2004).

• Stress-related states: It may be necessary to discontinue therapy and administer insulin if the patient is exposed to stress (fever, trauma, infection, surgery).

Special populations:

• Elderly: If therapy is initiated, dosing should be conservative; monitor closely for hypoglycemia.

Dosage form specific issues:

• Glyburide tablet formulations: Micronized glyburide tablets are not bioequivalent to conventional glyburide tablets; retitration should occur if patients are being transferred to a different glyburide formulation (eg, micronized-to-conventional or vice versa) or from other hypoglycemic agents.

Other warnings/precautions:

• Secondary failure: Loss of efficacy may be observed following prolonged use as a result of the progression of type 2 diabetes mellitus which results in continued beta cell destruction. In patients who were previously responding to sulfonylurea therapy, consider additional factors which may be contributing to decreased efficacy (eg, inappropriate dose, nonadherence to diet and exercise regimen). If no contributing factors can be identified, consider discontinuing use of the sulfonylurea due to secondary failure of treatment. Additional antidiabetic therapy (eg, insulin) will be required.

If you also take colesevelam, avoid taking it within 4 hours after you take glyburide.

Avoid drinking alcohol. It lowers blood sugar and may interfere with your diabetes treatment.

Glyburide could make you sunburn more easily. Avoid sunlight or tanning beds. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

Usual Adult Dose for Diabetes Type 2:

Standard glyburide:
-Initial dose: 2.5 mg to 5 mg orally once a day
-Dose titration: Increase in increments of no more than 2.5 mg at weekly intervals based upon blood glucose response
-Maintenance dose: 1.25 to 20 mg orally as a single dose or in divided doses
-Maximum dose: 20 mg/day

Micronized glyburide:
-Initial dose: 1.5 mg to 3 mg orally once a day
-Dose titration: Increase in increments of no more than 1.5 mg at weekly intervals based upon blood glucose response
-Maintenance dose: 0.75 to 12 mg orally as a single dose or in divided doses
-Maximum dose: 12 mg/day

Comments:
-Administer with breakfast or the first main meal of the day
-Lower initial doses may be used in patients who are sensitive to hypoglycemic drugs
-Once a day therapy is generally satisfactory, however, some patients may have a more satisfactory response with twice-a-day dosing, especially those receiving higher doses.

TRANSFER FROM OTHER HYPOGLYCEMIC THERAPY:
-Oral Antidiabetic Therapy: No exact dosage relationships exists between standard glyburide, micronized glyburide, or other oral hypoglycemic agents; when transferring patients from other oral hypoglycemic therapy, the maximum starting doses should be observed.
-Insulin:
--If the insulin dose is less than 20 units per day substitute 2.5 to 5 mg (standard) OR 1.5 to 3 mg (micronized) orally once a day.
--If the insulin dose is between 20 and 40 units per day, substitute 5 mg (standard) OR 3 mg (micronized) orally once a day.
--If the insulin dose is more than 40 units per day; transition the patient by concomitantly decreasing insulin by 50% and starting glyburide at 5 mg (standard) OR 3 mg (micronized) orally once a day; as insulin is progressively withdrawn, titrate glyburide in increments of 1.25 to 2.5 mg (standard) OR 0.75 to 1.5 mg (micronized) orally once a day every 2 to 10 days.

Use: As an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus.

Usual Geriatric Dose for Diabetes Type 2:

Initial dose: 1.25 to 2.5 mg (standard) orally or 0.75 to 1.5 mg (micronized) orally once a day.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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