Glipizide: Uses, Dosage, Side Effects, and More
1. Drug Name
Generic Name: Glipizide
Brand Name(s):
- Pakistan: Glucotrol, Minidiab
- India: Glucotrol, Gluconorm
- United States: Glucotrol, Glucotrol XL
- United Kingdom: Glibenese, Glibenese XL
2. Pharmacological Class
Class: Antidiabetic agent
Subclass: Sulfonylurea
3. Mechanism of Action
Glipizide stimulates the release of insulin from the pancreatic beta cells. It works by closing potassium channels in the beta cell membrane, which leads to the opening of calcium channels, resulting in increased intracellular calcium and subsequent release of insulin.
4. Indications
Primary Indications:
- Type 2 diabetes mellitus
Off-label Uses:
- Gestational diabetes (rarely used)
5. Dosage and Administration
Standard Dosage:
- Initial dose: 5 mg once daily, taken 30 minutes before breakfast.
- Maintenance dose: 2.5 to 40 mg daily in divided doses.
- Maximum dose: 40 mg daily.
Route of Administration: Oral
Special Populations:
- Pediatric: Not recommended.
- Geriatric: Start at lower doses due to increased risk of hypoglycemia.
6. Pharmacokinetics
Absorption: Rapidly absorbed from the gastrointestinal tract.
Distribution: Widely distributed, with 99% bound to plasma proteins.
Metabolism: Extensively metabolized in the liver.
Excretion: Primarily excreted in the urine as metabolites.
Half-life: Approximately 2-4 hours.
7. Contraindications
Glipizide is contraindicated in patients with:
- Hypersensitivity to glipizide or any of its components.
- Type 1 diabetes mellitus.
- Diabetic ketoacidosis.
8. Warnings and Precautions
Use caution in patients with:
- Hepatic or renal impairment.
- Elderly patients (increased risk of hypoglycemia).
- Adrenal or pituitary insufficiency.
Monitor blood glucose levels regularly to avoid hypoglycemia or hyperglycemia.
9. Side Effects
Common Side Effects:
- Hypoglycemia
- Nausea
- Diarrhea
- Dizziness
Serious Side Effects:
- Severe hypoglycemia
- Allergic reactions (rash, itching, swelling)
- Hepatotoxicity
10. Drug Interactions
Major Interactions:
- Beta-blockers (can mask hypoglycemia symptoms)
- Alcohol (can increase or decrease blood glucose levels)
Moderate Interactions:
- Nonsteroidal anti-inflammatory drugs (NSAIDs) (can potentiate hypoglycemic effect)
Minor Interactions:
- Warfarin (may affect blood glucose control)
11. Pregnancy and Lactation
Pregnancy Category: C
Breastfeeding Considerations: Not recommended during breastfeeding due to the potential risk to the infant.
12. Patient Counseling Information
Key Points for Patients:
- Take glipizide exactly as prescribed.
- Monitor blood glucose levels regularly and keep track of results.
- Recognize symptoms of hypoglycemia and know how to treat it.
- Follow dietary and exercise recommendations provided by your healthcare provider.
Administration Tips:
- Take glipizide 30 minutes before a meal, preferably breakfast.
- Do not skip meals while taking glipizide to avoid hypoglycemia.
- Store glipizide at room temperature away from moisture and heat.