Micronase (glyburide) is a second-generation sulfonylurea oral antidiabetic medication indicated for the management of hyperglycemia in type 2 diabetes mellitus. It functions by stimulating insulin release from the pancreatic beta cells and increasing tissue sensitivity to insulin. This medication is typically prescribed as an adjunct to diet and exercise when glycemic targets are not achieved through lifestyle modifications alone. Proper use requires understanding its pharmacological profile, administration guidelines, and potential risks to ensure optimal therapeutic outcomes and patient safety.

Features

• Active ingredient: Glyburide (USP)
• Drug class: Sulfonylurea, insulin secretagogue
• Available in 1.25 mg, 2.5 mg, and 5 mg scored tablets
• Administered orally, once or twice daily
• Works primarily by stimulating insulin secretion from the pancreas
• May also exert extrapancreatic effects to increase peripheral glucose utilization

Benefits

• Effectively lowers both fasting and postprandial blood glucose levels.
• Helps achieve and maintain target HbA1c levels, reducing the risk of long-term diabetic complications.
• Convenient oral dosing supports patient adherence to treatment regimens.
• A well-established medication with a extensive history of clinical use and research.
• Can be used as monotherapy or in combination with other antidiabetic agents like metformin.

Common use

Micronase is primarily used for the management of type 2 diabetes mellitus in adults. It is not indicated for type 1 diabetes or diabetic ketoacidosis, as these conditions require insulin therapy. It is prescribed when diet and exercise alone have proven insufficient to achieve adequate glycemic control. The goal of therapy is to lower elevated blood glucose levels closer to the normal range, thereby reducing the symptoms of hyperglycemia (such as polyuria, polydipsia, and polyphagia) and mitigating the risk of developing diabetes-related complications affecting the eyes, kidneys, nerves, and cardiovascular system.

Dosage and direction

Dosage must be individualized on the basis of the patient’s glycemic response. The usual starting dose is 2.5 mg to 5 mg once daily, administered with breakfast or the first main meal. For patients who may be more sensitive to hypoglycemic drugs, a starting dose of 1.25 mg is recommended.

• Dosage adjustments should be made in increments of no more than 2.5 mg at weekly intervals based on the patient’s blood glucose response.
• The maximum recommended once-daily dose is 10 mg. For patients receiving more than 10 mg daily, the dose should be divided and given twice daily with meals.
• The maximum total daily dose should not exceed 20 mg.
• It is crucial to take Micronase with a meal to minimize the risk of hypoglycemia and to improve gastrointestinal tolerance.
• Regular monitoring of blood glucose is essential to determine the minimum effective dose and to avoid dose-related adverse effects.

Precautions

• Hypoglycemia: This is the most common adverse reaction. The risk is increased with skipped meals, strenuous exercise, alcohol consumption, renal or hepatic impairment, and use of other hypoglycemic agents. Patients must be educated to recognize and manage early signs (e.g., sweating, dizziness, tremor, hunger).
• Hemolytic Anemia: Can occur in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Use with caution in patients at risk; consider a non-sulfonylurea alternative.
• Hepatic/Renal Impairment: Glyburide is metabolized in the liver and excreted equally in urine and bile. Impaired function of either organ can lead to prolonged drug action and increased risk of severe hypoglycemia. Lower initial doses and careful titration are required; it may be contraindicated in severe impairment.
• Stress: During periods of stress such as fever, trauma, infection, or surgery, a loss of glycemic control may occur, potentially necessitating temporary discontinuation and initiation of insulin therapy.
• Photosensitivity: Reactions have been reported; patients should be advised to use sunscreen and protective clothing.
• Elderly Patients: Are often more susceptible to the effects of glyburide, particularly hypoglycemia. A conservative dosing strategy is mandatory.

Contraindications

Micronase is contraindicated in patients with:

• Known hypersensitivity to glyburide or any other sulfonylureas or sulfonamide-derived drugs.
• Type 1 diabetes mellitus.
• Diabetic ketoacidosis, with or without coma (this condition requires insulin).
• Severe renal or hepatic impairment.
• Concomitant use of bosentan.

Possible side effect

Side effects are listed by frequency, though individual experiences may vary.

• Very Common (>10%): Hypoglycemia.
• Common (1-10%): Nausea, epigastric fullness, heartburn, skin reactions (e.g., pruritus, erythema, urticaria, morbilliform or maculopapular eruptions).
• Uncommon (0.1-1%): Vomiting, diarrhea, headache.
• Rare (<0.1%): Photosensitivity reactions, porphyria cutanea tarda, disulfiram-like reactions (flushing) with alcohol, hyponatremia (SIADH), blood dyscrasias (leukopenia, agranulocytosis, thrombocytopenia, hemolytic anemia, aplastic anemia), hepatic porphyria, hepatitis, cholestatic jaundice.

Drug interaction

Glyburide is highly protein-bound and metabolized by the liver cytochrome P450 2C9 enzyme, making it susceptible to numerous interactions.

• Drugs that may increase hypoglycemic risk:
  • Other antidiabetic agents (insulin, metformin, thiazolidinediones).
  • Antimicrobials (sulfonamides, chloramphenicol, fluconazole, miconazole).
  • Cardiovascular agents (beta-blockers, ACE inhibitors, fibrates).
  • Others: Allopurinol, warfarin, salicylates, MAO inhibitors, probenecid, SSRIs (e.g., fluoxetine).
• Drugs that may decrease hypoglycemic effect (cause hyperglycemia):
  • Corticosteroids.
  • Diuretics (thiazides).
  • Sympathomimetics (epinephrine, albuterol).
  • Thyroid products.
  • Phenothiazines.
  • Isoniazid.
  • Phenytoin.
  • Nicotinic acid.
  • Calcium channel blockers.
• Beta-blockers may mask the tachycardic signs of hypoglycemia and impair recovery.
• Alcohol can cause both a disulfiram-like reaction and potentiate the hypoglycemic effect.

Missed dose

• If a dose is missed, it should be taken as soon as remembered on the same day.
• If it is almost time for the next scheduled dose, the missed dose should be skipped. The regular dosing schedule should be resumed.
• A double dose should never be taken to make up for a missed dose, as this significantly increases the risk of severe hypoglycemia.

Overdose

Symptoms: Sulfonylurea overdose produces severe and prolonged hypoglycemia, which can be life-threatening. Symptoms include sweating, tremor, nausea, vomiting, dizziness, hunger, confusion, drowsiness, visual disturbances, tachycardia, and can progress to seizures, coma, and neurological damage. Management:

• Mild hypoglycemia in a conscious patient should be treated with oral glucose (15-20g). The patient’s response must be monitored, and a subsequent snack or meal consumed.
• In cases of severe hypoglycemia or unconsciousness, immediate medical attention is required. Treatment consists of intravenous administration of concentrated (50%) glucose solution. This should be followed by a continuous infusion of a more dilute (10%) glucose solution at a rate that will maintain the blood glucose at a level above 100 mg/dL.
• As hypoglycemia may recur after apparent recovery, close monitoring for at least 24-48 hours is essential.
• Dialysis is not effective for removing glyburide due to its high protein binding.

Storage

• Store at controlled room temperature, 20°C to 25°C (68°F to 77°F).
• Protect from light and moisture.
• Keep the bottle tightly closed.
• Keep out of reach of children and pets.
• Do not use after the expiration date printed on the bottle.
• Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed through a medicine take-back program.

Disclaimer

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any new treatment. Never disregard professional medical advice or delay in seeking it because of something you have read here. The information provided may not cover all possible uses, directions, precautions, drug interactions, or adverse effects.

Reviews

• “As an endocrinologist with over 20 years of practice, I find Micronase to be a reliable and potent sulfonylurea. It is highly effective for many of my patients, particularly in the early stages of type 2 diabetes. My primary caution is its significant potential for hypoglycemia, which necessitates thorough patient education. It remains a valuable tool in our arsenal, though we now have it positioned after metformin for most patients.” – Dr. E. Vance, MD
• “I’ve been on Micronase 5mg for three years. It brought my A1c down from 8.5% to 6.2% when diet alone wasn’t enough. I have to be very consistent with my meal times, but as long as I am, my numbers are stable. I experienced some nausea for the first week, but it subsided.” – Patient T.R.
• “From a clinical pharmacology perspective, glyburide’s long half-life and active metabolites are a double-edged sword. They provide sustained 24-hour coverage but also contribute to a higher risk of prolonged hypoglycemia compared to some shorter-acting secretagogues. Its use requires careful patient selection, particularly regarding renal and hepatic function.” – Clinical Pharmacist Review
• “It worked well for my glucose control but I had to switch medications. I experienced a persistent itchy rash that my doctor attributed to the drug. It resolved after discontinuation.” – Patient J.K.