Glyburide is the generic name for DiaBeta, Micronase and Glynase. These names will be used almost interchangeably here. It is an oral diabetes medicine that belongs to the sulfonylurea group. It was approved by the FDA in 1984. The combination of this drug and metformin is marketed under the brand name of Glucovance.

DiaBeta is supplied in 1.25mg, 2.5mg and 5mg tablets.

How Glyburide Works

DiaBeta, like other sulfonylureas, is a type 2 diabetic medicine that works by stimulating the beta cells of the pancreas to release more insulin than it would do without this diabetes medication. It may also use other mechanisms that are not yet known in lowering blood glucose during long term use. This is because sulfonylurea diabetes medication lose the ability to cause the pancreas to release insulin over time. This type 2 diabetes medication has been noted, in some cases, to continue to provide glycemic control during long term use, even after its ability to stimulate the pancreas to release insulin decreases.

How to Use Glyburide

Only a doctor can prescribe DiaBeta. The doctor usually starts patient on a lower dose and increase the dose in response to the patient’s blood sugar control achieved.

Micronase and all medicines with this generic name should be used in combination with diabetic diet and exercise to control type 2 diabetes.

The doctor usually starts with initial dose of 2.5mg to 5mg and increase or decrease in response to how well the blood glucose is being controlled. The maximum daily dose is 20mg. The doctor may start a patient at a daily dose lower than 2.5mg, if he/she determines that the patient may be prone to hypoglycemia. The maximum starting dose is 5mg daily.

Take once or twice daily. Twice daily is advocated for those patients who are receiving 10mg or more of total daily dose. Always take the first dose with the first meal of the day. If the patient takes this diabetes drug twice a day, the second dose should be taken with the evening meal.

Monitor finger-stick blood glucose regularly. Finger-stick blood sugar should be checked frequently, about 4 times a day during the introductory part of Glyburide regimen. Finger stick blood sugar should be reduced in frequency as blood sugar stabilizes.

Adverse Reactions to Glyburide

Hypoglycemia is a common adverse reaction of sulfonylurea. This is because of the release of extra insulin by the beta cells of the pancreas. All hypoglycemia should be treated and reported to the doctor. Use with caution in patients with liver, kidney, adrenal and/or pituitary disease or those with reduced food intake. Elderly patients are at the greatest risk. Concurrent administration of beta-blockers may decrease the patient’s ability to recognize the symptoms of hypoglycemia.

Diabetics on sulfonylurea have been found to have cardiovascular mortality that is higher than diabetics who are treated with diet alone or a combination of diabetic diet and insulin.

DiaBeta and other sulfonylureas have a tendency to stop working to reduce blood glucose after some time of effective use. This is called secondary failure. Secondary failure is a situation in which a medication that had been used effectively to treat a disease stops being effective against that disease.

Hemolytic anemia has been observed, especially in patients with glucose-6-phospate dehydrogenase (G6PD) deficiency.

There is possibility for jaundice, hepatitis and even liver failure.

The patient’s skin may become sensitive to light.

Allergic reaction may occur in the form of redness of the skin, itch, and rash. Other allergic reactions include muscle pain, joint pain, the inflammation of blood vessels known as vasculitis and the swelling of the tissue under the skin which is called angioedema or Quincke's edema.

There may be reduction in some blood cells.

Patients on this diabetic drug in some cases experience blurred vision.

Glyburide Drug interactions

This diabetic medication interacts with oral miconazole and this can lead to serious hypoglycemia. If patient on this medication needs to be treated with oral miconazole, the doctor may need to reduce the dose or stop it and use insulin and close blood glucose monitoring during the treatment period.

Fluoroquinolone antibiotics can cause hypoglycemia in patients who are taking Micronase and related drugs. Examples of fluoroquinolone antibiotics are Ciprofloxacin , levofloxacin, ofloxacin and other fluoroquinolones.

This diabetic medicine can produce disulfiram-like reaction with alcohol, but this is not common. These reactions are shortness of breath, nausea and vomiting, increased heart rate and flushing of the skin.

Sulfonylurea may react with the derivatives of coumarin and result in the increase or decrease of the action of the coumarin derivatives. An example of coumarin derivatives is warfarin, with Coumadin as one of its brand names.

Rifampin could interact with this drug and reduce the ability of Micronase to lower blood glucose.

Some medications cause blood sugar increase and may cause sulfonylurea drugs to lose its ability to lower blood glucose. Patients may require higher dose of DiaBeta when they are also taking those medications. In any event that any of those medications is discontinued, the glyburide dose should be decreased and patient should be monitored closely to avoid hyperglycemia or low blood glucose. Examples of these medicines that increase blood sugar are:

  • Diuretics, like hydrochlorothiazide
  • Corticosteroids, like prednisone
  • Oral contraceptive
  • Phenytoin
  • Calcium channel blockers
  • Isoniazid
  • Nicotinic acid
  • Albuterol
  • Thyroid hormone
  • And others.

Sulfonylurea increases the amount of cyclosporine in the blood and may lead to cyclosporine overdose. Patients on Glynase who have to take cyclosporine should get reduced dose and monitored closely.

Who Should Not Take Glyburide

  • Patients with type 1 diabetes should not take sulfonylurea. Type 1 diabetes is treated with insulin.
  • Patients in diabetic ketoacidosis or diabetic non-ketotic coma.
  • Patients with known cases of glucose-6-phospate dehydrogenase (G6PD) deficiency. This is because of the risk for hemolytic anemia.

Do Not

Do not give to patients who are:

Allergic to sulfonylurea or any other derivatives of sulfonamides.

In diabetic ketoacidosis or non-ketotic coma

Type 1 diabetics

Being treated with bosentan, which is a drug used to treat pulmonary artery hypertension.

Special considerations for the Use of Glyburide

Patients on Glyburide who are undergoing trauma, infection, sugery or other stresses, may need to be managed with insulin until they regain their baseline function.

Use in pregnancy only if potential benefit outweighs the risk. Babies who were born to mothers on glyburide have been observed to have protracted hypoglycemia. Insulin is the drug of choice for treating gestational diabetes.

Use with caution on women who are breastfeeding and only if the benefits clearly outweigh the risk. This is because some sulfonylurea medications are known to be secreted in the mother’s milk.

Do not use in pediatric patients because safety in this population has not been proven.

Use with caution in elderly patients because this population is more prone to hypoglycemia.

Patients, who are being switched from Diabinese with generic name of chlorpropamide, should be introduced at a lower dose and with caution. This is because chlorpropamide stays long in the blood and could contribute to hypoglycemia.

The brand name tablets are not always equivalent, so if a patient is switching from DiaBeta to Glynase or vice versa, the doctor should closely monitor the patient and adjust the dose as necessary. Always note that starting dose of DiaBeta should not exceed 5mg under any condition.

Glyburide Overdose

Overdose of glyburide and other sufonylureas can result in hypoglycemia. Overdose should be urgently treated by close blood glucose monitoring and hypoglycemia management. If resultant hypoglycemia is mild, patient can take foods that can release glucose quickly into the blood. This food can be glucose tablets, orange juice, skim milk, raw sugar or regular soda. In the event of severe hypoglycemia, patient should be taken to the nearest hospital emergency room and treated in hospital. Usually, patients in severe hypoglycemia are given glucagon and/or IV high concentration glucose solution. All episodes of hypoglycemia should be reported to the patient’s doctor.

Return from Glyburide to Home

Be the first to get new health tips by subscribing to our Diabetes Health Tips