Micronase

Actions

Glyburide appears to lower the blood glucose acutely by stimulating the release of insulin from the pancreas, an effect dependent upon functioning beta cells in the pancreatic islets. The mechanism by which glyburide lowers blood glucose during long-term administration has not been clearly established. With chronic administration in Type II diabetic patients, the blood glucose lowering effect persists despite a gradual decline in the insulin secretory response to the drug. Extrapancreatic effects may be involved in the mechanism of action of oral sulfonylurea hypoglycemic drugs. The combination of glyburide and metformin may have a synergistic effect, since both agents act to improve glucose tolerance by different but complementary mechanisms.

Some patients who are initially responsive to oral hypoglycemic drugs, including MICRONASE, may become unresponsive or poorly responsive over time. Alternatively, MICRONASE Tablets may be effective in some patients who have become unresponsive to one or more other sulfonylurea drugs.

In addition to its blood glucose lowering actions, glyburide produces a mild diuresis by enhancement of renal free water clearance. Disulfiram-like reactions have very rarely been reported in patients treated with MICRONASE Tablets.

Pharmacokinetics

Single dose studies with MICRONASE Tablets in normal subjects demonstrate significant absorption of glyburide within one hour, peak drug levels at about four hours, and low but detectable levels at twenty-four hours. Mean serum levels of glyburide, as reflected by areas under the serum concentration-time curve, increase in proportion to corresponding increases in dose. Multiple dose studies with MICRONASE in diabetic patients demonstrate drug level concentration-time curves similar to single dose studies, indicating no buildup of drug in tissue depots. The decrease of glyburide in the serum of normal healthy individuals is biphasic; the terminal half-life is about 10 hours. In single dose studies in fasting normal subjects, the degree and duration of blood glucose lowering is proportional to the dose administered and to the area under the drug level concentrationtime curve. The blood glucose lowering effect persists for 24 hours following single morning doses in nonfasting diabetic patients. Under conditions of repeated administration in diabetic patients, however, there is no reliable correlation between blood drug levels and fasting blood glucose levels. A one year study of diabetic patients treated with MICRONASE showed no reliable correlation between administered dose and serum drug level.

The major metabolite of glyburide is the 4-transhydroxy derivative. A second metabolite, the 3-cishydroxy derivative, also occurs. These metabolites probably contribute no significant hypoglycemic action in humans since they are only weakly active (1/400th and 1/40th as active, respectively, as glyburide) in rabbits. Glyburide is excreted as metabolites in the bile and urine, approximately 50% by each route. This dual excretory pathway is qualitatively different from that of other sulfonylureas, which are excreted primarily in the urine.

Sulfonylurea drugs are extensively bound to serum proteins. Displacement from protein binding sites by other drugs may lead to enhanced hypoglycemic action. In vitro, the protein binding exhibited by glyburide is predominantly non-ionic, whereas that of other sulfonylureas (chlorpropamide, tolbutamide, tolazamide) is predominantly ionic. Acidic drugs such as phenylbutazone, warfarin, and salicylates displace the ionic-binding sulfonylureas from serum proteins to a far greater extent than the non-ionic binding glyburide. It has not been shown that this difference in protein binding will result in fewer drug-drug interactions with MICRONASE Tablets in clinical use.

Glyburide is an oral diabetes medicine that helps control blood sugar levels.

Glyburide is used to treat type 2 diabetes.

This medication is not for treating type 1 diabetes.

Glyburide may also be used for other purposes not listed in this medication guide.

You should not use this medication if you are allergic to glyburide, if you are being treated with bosentan (Tracleer), if you have type 1 diabetes, or if you are in a state of diabetic ketoacidosis (call your doctor for treatment with insulin).

Before taking glyburide, tell your doctor if you are allergic to sulfa drugs, if you have been using insulin or chlorpropamide (Diabinese), or if you have hemolytic anemia (a lack of red blood cells), an enzyme deficiency (G6PD), a nerve disorder, liver disease, or kidney disease.

Take care not to let your blood sugar get too low. Low blood sugar (hypoglycemia) can occur if you skip a meal, exercise too long, drink alcohol, or are under stress. Symptoms include headache, hunger, weakness, sweating, tremor, irritability, or trouble concentrating. Carry hard candy or glucose tablets with you in case you have low blood sugar. Other sugar sources include orange juice and milk. Be sure your family and close friends know how to help you in an emergency.

Micronase is a prescription medication used in the management of type 2 diabetes mellitus. It helps to lower the amount of glucose (sugar) in the blood.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Tell your doctor about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

• angiotensin-converting enzyme (ACE) inhibitors such as benazepril (Lotensin), captopril (Capoten), enalapril (Vasotec), fosinopril (Monopril), lisinopril (Prinivil, Zestril), moexipril (Univasc), perindopril, (Aceon), quinapril (Accupril), ramipril (Altace), and trandolapril (Mavik)
• anticoagulants ('blood thinners') such as warfarin (Coumadin, Jantoven)
• aspirin and other nonsteroidal anti-inflammatory medications (NSAIDs) such as ibuprofen (Advil, Motrin) and naproxen (Aleve, Naprosyn)
• beta blockers such as atenolol (Tenormin), labetalol (Normodyne), metoprolol (Lopressor, Toprol XL), nadolol (Corgard), and propranolol (Inderal)
• bosentan(Tracleer)
• calcium channel blockers such as amlodipine (Norvasc), diltiazem (Cardizem, Dilacor, Tiazac, others), felodipine (Plendil), isradipine (DynaCirc), nicardipine (Cardene), nifedipine (Adalat, Procardia), nimodipine (Nimotop), nisoldipine (Sular), and verapamil (Calan, Isoptin, Verelan)
• chloramphenicol
• clarithromycin (Biaxin)
• cyclosporine (Neoral, Sandimmune)
• disopyramide (Norpace)
• diuretics ('water pills')
• fluconazole (Diflucan)
• fluoxetine (Prozac, Sarafem)
• hormone replacement therapy and hormonal contraceptives (birth control pills, patches, rings, implants, and injections)
• insulin or other medications to treat high blood sugar or diabetes
• isoniazid (INH)
• MAO inhibitors such as isocarboxazid (Marplan), phenelzine (Nardil), selegiline (Eldepryl, Emsam, Zelapar), and tranylcypromine (Parnate)
• medications for asthma and colds
• medications for mental illness and nausea
• miconazole (Monistat)
• niacin
• oral steroids such as dexamethasone (Decadron, Dexone), methylprednisolone (Medrol), and prednisone (Deltasone)
• phenytoin (Dilantin)
• probenecid (Benemid)
• quinolone and fluoroquinolone antibiotics such as cinoxacin (Cinobac), ciprofloxacin (Cipro), enoxacin (Penetrex), gatifloxacin (Tequin), levofloxacin (Levaquin), lomefloxacin (Maxaquin), moxifloxacin (Avelox), nalidixic acid (NegGram), norfloxacin (Noroxin), ofloxacin (Floxin), sparfloxacin (Zagam), trovafloxacin and alatrofloxacin combination (Trovan)
• rifampin
• salicylate pain relievers such as choline magnesium trisalicylate, choline salicylate (Arthropan), diflunisal (Dolobid), magnesium salicylate (Doan's, others), and salsalate (Argesic, Disalcid, Salgesic)
• sulfa antibiotics such as co-trimoxazole (Bactrim, Septra)
• sulfasalazine (Azulfidine)
• thyroid medications

This is not a complete list of Micronase drug interactions. Ask your doctor or pharmacist for more information.

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

If Micronase 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.

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies have not been performed on the relationship of age to the effects of glyburide in the pediatric population. Safety and efficacy have not been established.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of glyburide in the elderly. However, elderly patients are more likely to have age-related liver or kidney problems, which may require an adjustment in the dose for patients receiving glyburide.

Pregnancy

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

• Bosentan

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Acarbose
• Aspirin
• Balofloxacin
• Besifloxacin
• Ciprofloxacin
• Disopyramide
• Dulaglutide
• Enoxacin
• Entacapone
• Fleroxacin
• Flumequine
• Gatifloxacin
• Gemifloxacin
• Lanreotide
• Levofloxacin
• Lixisenatide
• Lomefloxacin
• Metreleptin
• Moxifloxacin
• Nadifloxacin
• Norfloxacin
• Octreotide
• Ofloxacin
• Pasireotide
• Pazufloxacin
• Pefloxacin
• Pioglitazone
• Prulifloxacin
• Rufloxacin
• Simeprevir
• Sparfloxacin
• Thioctic Acid
• Tosufloxacin

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Acebutolol
• Aminolevulinic Acid
• Atenolol
• Betaxolol
• Bisoprolol
• Bitter Melon
• Carteolol
• Carvedilol
• Celiprolol
• Clarithromycin
• Colesevelam
• Cyclosporine
• Esmolol
• Fenugreek
• Fluvastatin
• Furazolidone
• Gemfibrozil
• Glucomannan
• Iproniazid
• Isocarboxazid
• Labetalol
• Levobunolol
• Linezolid
• Methylene Blue
• Metipranolol
• Metoprolol
• Moclobemide
• Nadolol
• Nebivolol
• Nialamide
• Oxprenolol
• Penbutolol
• Phenelzine
• Pindolol
• Practolol
• Procarbazine
• Propranolol
• Psyllium
• Rasagiline
• Rifampin
• Rifapentine
• Safinamide
• Saxagliptin
• Selegiline
• Sotalol
• Timolol
• Tranylcypromine
• Voriconazole
• Warfarin

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco.

• Ethanol

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Alcohol intoxication or
• Underactive adrenal glands or
• Underactive pituitary gland or
• Undernourished condition or
• Weakened physical condition or
• Any other condition that causes low blood sugar—Patients with these conditions may be more likely to develop low blood sugar while taking glyburide.

• Diabetic ketoacidosis (ketones in the blood) or
• Type I diabetes—Should not be used in patients with these conditions.

• Fever or
• Infection or
• Surgery or
• Trauma—These conditions may cause temporary problems with blood sugar control and your doctor may want to treat you temporarily with insulin.

• Glucose-6-phosphate dehydrogenase (G6PD) deficiency (an enzyme problem)—May cause hemolytic anemia (a blood disorder) in patients with this condition.

• Heart disease—Use with caution. May make this condition worse.

• Kidney disease or
• Liver disease—Use with caution. Effects may be increased because of slower removal of the medicine from the body.

Overdosage of sulfonylureas, including Micronase Tablets, can produce hypoglycemia. Mild hypoglycemic symptoms, without loss of consciousness or neurological findings, should be treated aggressively with oral glucose and adjustments in drug dosage and/or meal patterns. Close monitoring should continue until the physician is assured that the patient is out of danger. Severe hypoglycemic reactions with coma, seizure, or other neurological impairment occur infrequently, but constitute medical emergencies requiring immediate hospitalization. If hypoglycemic coma is diagnosed or suspected, the patient should be given a rapid intravenous injection of concentrated (50%) glucose solution. This should be followed by a continuous infusion of a more dilute (10%) glucose solution at a rate which will maintain the blood glucose at a level above 100 mg/dL. Patients should be closely monitored for a minimum of 24 to 48 hours, since hypoglycemia may recur after apparent clinical recovery.

There is no fixed dosage regimen for the management of diabetes mellitus with Micronase Tablets or any other hypoglycemic agent. In addition to the usual monitoring of urinary glucose, the patient's blood glucose must also be monitored periodically to determine the minimum effective dose for the patient; to detect primary failure, ie, inadequate lowering of blood glucose at the maximum recommended dose of medication; and to detect secondary failure, ie, loss of adequate blood glucose lowering response after an initial period of effectiveness. Glycosylated hemoglobin levels may also be of value in monitoring the patient's response to therapy.

Short-term administration of Micronase may be sufficient during periods of transient loss of control in patients usually controlled well on diet.

Usual Starting Dose

The usual starting dose of Micronase Tablets is 2.5 to 5 mg daily, administered with breakfast or the first main meal. Those patients who may be more sensitive to hypoglycemic drugs should be started at 1.25 mg daily. (See PRECAUTIONS section for patients at increased risk.) Failure to follow an appropriate dosage regimen may precipitate hypoglycemia. Patients who do not adhere to their prescribed dietary and drug regimen are more prone to exhibit unsatisfactory response to therapy.

Transfer of patients from other oral antidiabetic regimens to Micronase should be done conservatively and the initial daily dose should be 2.5 to 5 mg. When transferring patients from oral hypoglycemic agents other than chlorpropamide to Micronase, no transition period and no initial or priming dose are necessary. When transferring patients from chlorpropamide, particular care should be exercised during the first two weeks because the prolonged retention of chlorpropamide in the body and subsequent overlapping drug effects may provoke hypoglycemia.

Some Type II diabetic patients being treated with insulin may respond satisfactorily to Micronase. If the insulin dose is less than 20 units daily, substitution of Micronase Tablets 2.5 to 5 mg as a single daily dose may be tried. If the insulin dose is between 20 and 40 units daily, the patient may be placed directly on Micronase Tablets 5 mg daily as a single dose. If the insulin dose is more than 40 units daily, a transition period is required for conversion to Micronase. In these patients, insulin dosage is decreased by 50% and Micronase Tablets 5 mg daily is started. Please refer to Titration to Maintenance Dose for further explanation.

Titration to Maintenance Dose

The usual maintenance dose is in the range of 1.25 to 20 mg daily, which may be given as a single dose or in divided doses (See Dosage Interval section). Dosage increases should be made in increments of no more than 2.5 mg at weekly intervals based upon the patient's blood glucose response.

No exact dosage relationship exists between Micronase and the other oral hypoglycemic agents. Although patients may be transferred from the maximum dose of other sulfonylureas, the maximum starting dose of 5 mg of Micronase Tablets should be observed. A maintenance dose of 5 mg of Micronase Tablets provides approximately the same degree of blood glucose control as 250 to 375 mg chlorpropamide, 250 to 375 mg tolazamide, 500 to 750 mg acetohexamide, or 1000 to 1500 mg tolbutamide.

When transferring patients receiving more than 40 units of insulin daily, they may be started on a daily dose of Micronase Tablets 5 mg concomitantly with a 50% reduction in insulin dose. Progressive withdrawal of insulin and increase of Micronase in increments of 1.25 to 2.5 mg every 2 to 10 days is then carried out. During this conversion period when both insulin and Micronase are being used, hypoglycemia may rarely occur. During insulin withdrawal, patients should test their urine for glucose and acetone at least three times daily and report results to their physician. The appearance of persistent acetonuria with glycosuria indicates that the patient is a Type I diabetic who requires insulin therapy.

Concomitant Glyburide and Metformin Therapy

Micronase Tablets should be added gradually to the dosing regimen of patients who have not responded to the maximum dose of metformin monotherapy after four weeks (see Usual Starting Dose and Titration to Maintenance Dose). Refer to metformin package insert.

With concomitant glyburide and metformin therapy, the desired control of blood glucose may be obtained by adjusting the dose of each drug. However, attempts should be made to identify the optimal dose of each drug needed to achieve this goal. With concomitant glyburide and metformin therapy, the risk of hypoglycemia associated with sulfonylurea therapy continues and may be increased. Appropriate precautions should be taken (see PRECAUTIONS section).

Maximum Dose

Daily doses of more than 20 mg are not recommended.

Dosage Interval

Once-a-day therapy is usually satisfactory. Some patients, particularly those receiving more than 10 mg daily, may have a more satisfactory response with twice-a-day dosage.

Specific Patient Populations

Micronase is not recommended for use in pregnancy or for use in pediatric patients.

In elderly patients, debilitated or malnourished patients, and patients with impaired renal or hepatic function, the initial and maintenance dosing should be conservative to avoid hypoglycemic reactions. (See PRECAUTIONS section.)

NDC 0009-0131-01

100 Tablets
Rx only

Micronase®
glyburide
tablets, USP

1.25 mg

Pfizer
Distributed by
Pharmacia & Upjohn Co
Division of Pfizer Inc, NY, NY 10017