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.
กลไกการออกฤทธิ์: **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.
ขนาดยาตามชนิดสัตว์
- 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.
ขนาดยาเป็นข้อมูลอ้างอิงทางคลินิกสำหรับสัตวแพทย์ผู้มีใบอนุญาต โปรดตรวจสอบกับฉลากล่าสุดและผู้ป่วยแต่ละรายเสมอ
วิธีการให้ยา
ข้อห้ามใช้
- 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
อาการไม่พึงประสงค์
- Vomiting (most common)
- Headache (reported in humans)
- Nausea
- Thirst
- Diarrhea
อันตรกิริยาระหว่างยา
- 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.
การติดตาม
- Intraocular pressure (IOP)
- Urine output
- Hydration status
การได้รับยาเกินขนาด
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.
ข้อมูลอ้างอิงยาของ VetSheet มีไว้สำหรับสัตวแพทย์ผู้มีใบอนุญาตเพื่อช่วยในการตัดสินใจทางคลินิก ไม่ใช่สิ่งทดแทนการวินิจฉัยของผู้เชี่ยวชาญหรือฉลากล่าสุดของผู้ผลิต