Glycerin
**Glycerin** (also known as glycerol) is a potent, orally administered hyperosmotic agent. In veterinary medicine, it is primarily utilized in emergency settings for the rapid, short-term reduction of **intraocular pressure (IOP)** in patients suffering from acute glaucoma, and occasionally to reduce cerebrospinal fluid (CSF) pressure. * **Key Advantages**: Unlike mannitol, which requires intravenous administration, glycerin can be given orally, making it highly accessible for immediate clinic use during an ocular emergency. * **Clinical Pearl**: Because glycerin is metabolized into carbohydrates (glucose) in the liver, it provides a caloric load and can significantly elevate blood glucose levels. Therefore, it is generally contraindicated or used with extreme caution in diabetic patients.
Mecanismo: **Glycerin** exerts its effects purely through physical osmotic forces rather than specific receptor interactions. * **Osmotic Gradient**: When administered orally, it rapidly increases the osmolality of the blood plasma. * **Fluid Shift**: This hyperosmolar state draws water from extravascular spaces (including the aqueous and vitreous humor of the eye, and cerebrospinal fluid) into the intravascular space → **Decreased IOP** and **Decreased CSF pressure**. * **Metabolism**: Once in the liver, glycerin is metabolized via the enzyme **glycerol kinase** → glycerol-3-phosphate → enters glycolysis and gluconeogenesis pathways.
Dosificación por especie
- Acute glaucoma · 1-2 g/kg PO as a 50% oral solution · PO · single dose
- Acute glaucoma · 1-2 mL/kg (of a 90% solution) PO · PO · single dose · Withhold water for 3-4 hours after administration.
- Acute glaucoma (emergency reduction of IOP) · 1.1-2.2 mL/kg (0.5-1 mL/lb) of 90% syrup · PO · single dose · Mix with an equal volume of ice cream or milk to help reduce vomiting.
- Acute glaucoma · 1-2 g/kg PO as a 50% oral solution · PO · single dose
- Acute glaucoma · 1-2 mL/kg (of a 90% solution) PO · PO · single dose · Withhold water for 3-4 hours after administration.
- Acute glaucoma (emergency reduction of IOP) · 1.1-2.2 mL/kg (0.5-1 mL/lb) of 90% syrup · PO · single dose · Mix with an equal volume of ice cream or milk to help reduce vomiting.
Las dosis son una referencia clínica para médicos veterinarios. Confirme siempre con la información vigente del producto y el paciente individual.
Vías de administración
Contraindicaciones
- Known hypersensitivity to glycerin
- Well-established anuria
- Severe dehydration
- Severe cardiac decompensation
- Frank or impending acute pulmonary edema
- Diabetes mellitus (relative/absolute depending on source)
- Chronic renal failure or compromised renal function
Efectos adversos
- Vomiting (most common)
- Headache (reported in humans)
- Nausea
- Thirst
- Diarrhea
Interacciones farmacológicas
- Carbonic anhydrase inhibitors (e.g., acetazolamide, dichlorphenamide) · Concomitant administration may prolong the IOP-reducing effects of glycerin.
- Topical miotic agents · Concomitant administration may prolong the IOP-reducing effects of glycerin.
Monitoreo
- Intraocular pressure (IOP)
- Urine output
- Hydration status
Sobredosis
Specific veterinary overdose information is limited. However, **cardiac arrhythmias**, **non-ketotic hyperosmolar coma**, and **severe dehydration** have been reported with the drug. Treatment should be supportive and symptomatic, focusing on restoring fluid and electrolyte balance.
La referencia de fármacos de VetSheet está destinada a médicos veterinarios como apoyo a la decisión clínica; no sustituye el juicio profesional ni la información vigente del fabricante.