Glyburide
Glyburide (also known as glibenclamide) is a **second-generation sulfonylurea** oral antidiabetic agent. In veterinary medicine, it is primarily used as an alternative oral treatment for **non-insulin dependent diabetes mellitus (NIDDM)** in cats. Key clinical points: * **Alternative to Glipizide:** It is typically considered when glipizide is unavailable or when a once-daily dosing regimen is strongly preferred by the owner. * **Insulin is Superior:** While oral hypoglycemics can be trialed, **insulin therapy remains the gold standard** and is generally preferred for feline diabetes. * **Efficacy:** Glyburide may not be effective in cats demonstrating significant insulin resistance or those with depleted pancreatic beta-cell function.
Mecanismo: Glyburide lowers blood glucose concentrations by stimulating the secretion of endogenous insulin from functional pancreatic beta cells. **Mechanism of Action:** * Binds to **sulfonylurea receptor 1 (SUR1)** subunits on **ATP-sensitive potassium channels (K-ATP)** in the pancreatic beta-cell membrane. * **K-ATP channel closure** → cell membrane depolarization. * Depolarization triggers the opening of **voltage-dependent calcium channels** → **Calcium influx**. * Increased intracellular calcium promotes the exocytosis of **insulin** granules. **Extrapancreatic Effects:** With long-term administration, glyburide may also enhance insulin activity at post-receptor sites and reduce basal hepatic glucose production.
Dosificación por especie
- Non-insulin dependent diabetes mellitus (NIDDM) · 0.625 mg (1/2 of a 1.25 mg tablet) · PO · once daily · Initial dose
- Non-insulin dependent diabetes mellitus (NIDDM) · 2.5 mg (total dose) · PO · twice a day · If cat is generally well, weight loss is mild, is not ketoacidotic, and does not have peripheral neuropathy
Las dosis son una referencia clínica para veterinarios colegiados. Confirme siempre con la ficha técnica vigente y el paciente individual.
Vías de administración
Contraindicaciones
- Severe burns
- Severe trauma
- Severe infection
- Diabetic coma or other hypoglycemic conditions
- Major surgery
- Ketosis
- Ketoacidosis or other significant acidotic conditions
Efectos adversos
- Vomiting
- Hypoglycemia
- Liver toxicity (icterus, increased ALT/SGPT)
- Allergic skin reactions (reported in humans)
- Arthralgia (reported in humans)
- Bone marrow suppression (reported in humans)
- Cholestatic jaundice (reported in humans)
Interacciones farmacológicas
- Alcohol · A disulfiram-like reaction (anorexia, nausea, vomiting) is possible
- Azole Antifungals (ketoconazole, itraconazole, fluconazole) · May increase plasma levels of glyburide
- Beta-blockers · May potentiate hypoglycemic effect
- Chloramphenicol · May displace glyburide from plasma proteins
- Cimetidine · May potentiate hypoglycemic effect
- Corticosteroids · May reduce efficacy
- Thiazide Diuretics · May reduce hypoglycemic efficacy
- Isoniazid · May reduce hypoglycemic efficacy
- MAO Inhibitors · May potentiate hypoglycemic effect
- Niacin · May reduce hypoglycemic efficacy
- Phenothiazines · May reduce hypoglycemic efficacy
- Phenytoin · May reduce hypoglycemic efficacy
- Probenecid · May potentiate hypoglycemic effect
- Sulfonamides · May displace glyburide from plasma proteins
Monitorización
- Physical examination (weekly during first month)
- Body weight (weekly during first month)
- Urine glucose and ketones (weekly during first month)
- Serial blood glucose exams (weekly during first month)
- Clinical signs of adverse effects (vomiting, icterus)
- Liver enzymes (ALT/SGPT) occasionally
- Complete Blood Count (CBC) occasionally
Sobredosis
> **Emergency Warning:** Profound **hypoglycemia** is the greatest concern after an overdose. * In humans, severe hypoglycemia has occurred at relatively low dosages. * **Decontamination:** Gut emptying protocols should be employed when warranted and if the patient is neurologically stable. * **Treatment:** Because its half-life is longer than glipizide, prolonged hypoglycemia may occur. Continuous blood glucose monitoring and treatment with parenteral glucose (IV dextrose) may be required for several days. * **Monitoring:** Massive overdoses may also require additional monitoring (blood gases, serum electrolytes) and supportive therapy.
La referencia de fármacos de VetSheet está destinada a veterinarios colegiados como apoyo a la decisión clínica, no sustituye el juicio profesional ni la ficha técnica vigente del fabricante.