How does this medication work? What will it do for me?

Glyburide is an antidiabetes medication that belongs to the family of medications known as sulfonylureas. It is used to treat high blood sugar (hyperglycemia) in people with type 2 diabetes.

Antidiabetes medications such as glyburide are used when diet, exercise, and weight reduction have not been found to lower blood sugar well enough on their own. Glyburide increases the release of insulin (a hormone produced by the pancreas that allows sugar to enter into cells where it is needed for energy) and helps the body use insulin more efficiently.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

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What form(s) does this medication come in?

2.5 mg
Each white, round tablet, flat-faced with bevelled edges, scored and identified "APO" over "2.5" on one side, contains glyburide 2.5 mg. Nonmedicinal ingredients: croscarmellose sodium, lactose, magnesium stearate, and microcrystalline cellulose.

5 mg
Each white, capsule-shaped tablet, flat-faced with bevelled edges, scored on one side and identified "APO 5" on the other side, contains glyburide 5 mg. Nonmedicinal ingredients: croscarmellose sodium, lactose, magnesium stearate, and microcrystalline cellulose.

How should I use this medication?

The recommended adult starting dose of glyburide is usually 5 mg daily (2.5 mg for patients over 60 years of age) and increases or decreases by 2.5 mg every 5 to 7 days until blood sugar is controlled. The recommended adult dose of glyburide ranges from 2.5 mg once daily to 10 mg twice daily. The maximum dose of glyburide is 20 mg daily.

Glyburide should be taken during or immediately after a meal, usually with breakfast or the first main meal of the day. If you eat only a light breakfast, wait until lunchtime to take your morning dose.

Many things can affect the dose of a medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

Low blood sugar (hypoglycemia) is an important concern if too much of this medication is taken. Ask your doctor or diabetes educator what you should do when you are not going to be eating for a long period of time or when you are going to be exercising more than usual.

It is very important to monitor blood sugar levels closely, especially when increasing and decreasing doses of medication or when exercise level or weight changes occur. Your doctor or diabetes educator will instruct you on the best use of a diabetes monitor.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture and keep it out of reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

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Who should NOT take this medication?

Do not take glyburide if you:

  • are allergic to glyburide or any ingredients of the medication
  • are allergic to sulfonylurea or sulphonamide medictions
  • are breast-feeding or pregnant
  • are in a diabetic coma or pre-coma (a result of hypoglycemia - symptoms include speech and visual disturbances, flushing, trembling, headache, nausea, vomiting)
  • are taking the medication bosentan
  • are undergoing surgery or has recently suffered severe trauma (a loss of blood sugar control may occur and insulin administration may be required)
  • have diabetic ketoacidosis with or without coma
  • have a serious infection (a loss of blood sugar control may occur and insulin administration may be required)
  • have jaundice
  • have serious kidney or liver impairment
  • have type 1 diabetes
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What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • constipation
  • diarrhea
  • difficulty in focusing the eyes
  • dizziness
  • heartburn
  • increased amount of urine or more frequent urination
  • increased or decreased appetite
  • increased sensitivity of the skin to sun
  • nausea
  • stomach pain, fullness, or discomfort
  • vomiting

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • low blood sugar, including:
    • anxious feelings
    • behavioural changes similar to being drunk
    • blurred vision
    • cold sweats
    • confusion
    • cool, pale skin
    • difficulty concentrating
    • drowsiness
    • excessive hunger
    • fast heartbeat
    • headache
    • nausea
    • nervousness
    • nightmares
    • restless sleep
    • shakiness
    • slurred speech
    • unusual tiredness or weakness
  • low blood pressure (e.g., dizziness, pale skin, fainting)
  • skin redness, itching, or rash
  • signs of bleeding (e.g., bloody nose, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
  • signs of infection (symptoms may include fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness)
  • signs of liver problems (e.g., nausea, vomiting,diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
  • thinning of the skin
  • unusual tiredness or weakness
  • unusual weight gain

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • convulsions (seizures)
  • shock (e.g., cold, damp skin; confusion; shakiness; nausea; weak, rapid pulse)
  • signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
  • unconsciousness

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

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Are there any other precautions or warnings for this medication?

Before you begin taking a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should take this medication.

Allergy: Some people who are allergic to sulphonamide antibiotics and other sulfonylurea anti-diabetes medications also experience allergic reactions to glyburide. Before you take glyburide, inform your doctor about any previous adverse reactions you have had to medications, especially sulfamethoxazole or glipizide. Contact your doctor at once if you experience signs of an allergic reaction, such as skin rash, itching, difficulty breathing or swelling of the face and throat.

Blood sugar control: For people who take glyburide, loss of blood sugar control may occur during illness or stressful situations such as trauma or surgery. Under these conditions, your doctor may consider stopping the medication and prescribing insulin until the situation improves.

Diabetes complications: The use of glyburide (or any other medication used for diabetes) will not prevent the development of complications peculiar to diabetes mellitus (e.g., kidney disease, nerve disease, eye disease).

Diet and exercise: Glyburide should be used in addition to a proper dietary regimen and exercise. If you do not follow a proper dietary and exercise regimen, it is more likely that glyburide will not work, and your diabetes will get worse.

Kidney function: If you have reduced kidney function or kidney disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function:Liver disease or reduced liver function may cause this medication to build up in the body, which will cause side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking this medication.

If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Low blood sugar: As with other sulfonylurea medications like gliclazide or glimepiride, hypoglycemia (low blood sugar) may occur. Situations which may bring this on include:

  • advanced age
  • alcoholism
  • certain thyroid diseases
  • exercise without adequate calorie intake
  • liver disease or kidney disease
  • malnutrition or irregular meals

Signs of low blood sugar include:

  • dizziness
  • drowsiness
  • headache
  • lack of energy
  • nervousness
  • numbness or tingling
  • shakiness
  • sweating
  • weakness

Monitor your blood glucose regularly and keep emergency glucose (and a glucagon kit) available in case you need to increase blood sugar levels quickly. Talk with your doctor or diabetes educator about this.

Mental or physical abilities: This medication may reduce the mental or physical abilities required for hazardous tasks such as driving or operating dangerous machinery. Use appropriate caution until you have gained control of your blood sugar, or when changing doses of medication, or when the tablets have not been taken regularly.

Reduced response: Over time, glyburide may become less effective as your diabetes worsens. If glyburide fails to lower your blood glucose to target levels, it should be stopped and replaced, or another medication for diabetes should be added to it. Monitor your blood glucose levels regularly and if you notice them getting higher, contact your doctor to discuss alternatives.

Pregnancy: Glyburide should not be used during pregnancy. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: This medication may pass into breast milk. If you are a breast-feeding mother and are taking glyburide, it may affect your baby. Glyburide is not recommended for use by breast-feeding women.

Children: The safety and effectiveness of using this medication have not been established for children under the age of 18.

Seniors: Seniors with type 2 diabetes may be more likely to experience very low blood sugar as a result of using glyburide. Lower doses may be necessary.

What other drugs could interact with this medication?

There may be an interaction between glyburide and any of the following:

  • ACE inhibitors (e.g., enalapril, ramipril)
  • acetazolamide
  • additional antidiabetes medications (e.g. insulin, rosiglitazone, tolbutamide)
  • alcohol
  • amiodarone
  • anabolic steroids
  • androgens
  • aprepitant
  • atovaquone
  • "azole" antifungals (e.g., fluconazole, ketoconazole, voriconazole)
  • barbiturates (e.g., phenobarbital, secobarbital)
  • beta-blockers(e.g. atenolol, carvedilol, propranolol)
  • birth control pills
  • bosentan
  • carbamazepine
  • chloramphenicol
  • clarithromycin
  • clofibrate
  • clonidine
  • corticosteroids(e.g., budesonide, dexamethasone, hydrocortisone, prednisone)
  • cyclophosphamide
  • cyclosporine
  • delaviridine
  • diazoxide
  • disopyramide
  • diuretics (e.g., furosemide, hydrochlorothiazide, indapamide)
  • efavirenz
  • epinephrine
  • fenofibric acid
  • fluorouracil
  • fluoxetine
  • gemfibrozil
  • glucagon
  • goserelin
  • ifosfamide
  • irbesartan
  • laxatives
  • leuprolide
  • losartan
  • MAO inhibitors (e.g., phenelzine, selegiline, tranylcypromine)
  • nicardipine
  • nicotinic acid
  • nilotinib
  • omeprazole
  • oxyphenbutazone
  • para-aminosalicylic acid
  • peg-interferon alfa-2b
  • phenothiazines
  • phenylbutazone
  • phenytoin
  • pimozide
  • primidone
  • probenecid
  • pyrimethamine
  • quinine
  • quinolone antibiotics (e.g., ciprofloxacin, levofloxacin, ofloxacin)
  • ranitidine
  • reserpine
  • rifampin
  • salicylates
  • selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, fluoxetine, paroxetine, sertraline)
  • sulfinpyrazone
  • sulphonamides (e.g., sulfimethoxazole, sulfisoxazole)
  • sympatholytic agents (e.g., guanethidine)
  • tetracyclines
  • thyroid hormone
  • trimethoprim
  • tuberculostatics
  • warfarin
  • zafirlukast

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.