升糖素
**升糖素**是一種由胰臟α2細胞分泌的多肽荷爾蒙。在獸醫學中，主要用於治療因胰島素瘤或胰島素過量引起的嚴重低血糖。此外，它在治療乳牛脂肪肝綜合症方面也具潛力。
作用機制: Glucagon acts as a physiological antagonist to insulin, primarily targeting the liver to increase blood glucose levels. * Binds to specific **glucagon receptors (GPCRs)** on the surface of hepatocytes. * Activates **adenylate cyclase** → increases intracellular **cAMP** → activates **protein kinase A (PKA)**. * This cascade stimulates **glycogen phosphorylase** and inhibits glycogen synthase, leading to rapid **hepatic glycogenolysis** (breakdown of stored glycogen into glucose) and **gluconeogenesis**. * Also causes relaxation of gastrointestinal smooth muscle through poorly understood mechanisms (likely cAMP-mediated).
各物種劑量
- Hypoglycemic (neuroglycopenic) crises in patients with 'insulinomas' · Initially give a 50 ng/kg bolus IV and then administer at a constant rate infusion (CRI) using a suitable pump at a rate of 10-15 ng/kg/minute. May need to increase up to 40 ng/kg/min to maintain euglycemia. · IV · Bolus followed by CRI · 1 mg of glucagon is reconstituted per manufacturer directions and then added to 1000 mL of 0.9% Sodium Chloride; this results in a 1000 ng/mL solution. [Note: Some references state to not mix or dilute with saline solutions, but to use D5W only.]
- Hypoglycaemia (Insulin overdose) · 50 ng/kg once followed by infusion of 10-15 ng/kg/min; may increase up to 40 ng/kg/min depending on blood glucose measurements · IV/IM · once, then continuous infusion · As needed based on blood glucose · Monitor blood glucose hourly
- Treatment of fatty liver in early lactation dairy cows older than 3.5 years · 5 mg glucagon in 60 mL of normal saline SC q8h (15 mg/day) · SC · q8h · 14 days
- Hypoglycemic (neuroglycopenic) crises in patients with 'insulinomas' · Initially give a 50 ng/kg bolus IV and then administer at a constant rate infusion (CRI) using a suitable pump at a rate of 10-15 ng/kg/minute. May need to increase up to 40 ng/kg/min to maintain euglycemia. · IV · Bolus followed by CRI · 1 mg of glucagon is reconstituted per manufacturer directions and then added to 1000 mL of 0.9% Sodium Chloride; this results in a 1000 ng/mL solution. [Note: Some references state to not mix or dilute with saline solutions, but to use D5W only.]
- Refractory hypoglycemic patients with insulinoma · Give at an initial infusion rate of 5 ng/kg/min and increase as needed. · IV · CRI · Prepare solution as 1000 ng/mL.
- Hypoglycaemia (Insulin overdose) · 50 ng/kg once followed by infusion of 10-15 ng/kg/min; may increase up to 40 ng/kg/min depending on blood glucose measurements · IV/IM · once, then continuous infusion · As needed based on blood glucose · Monitor blood glucose hourly
劑量為持牌獸醫專業人員的臨床參考。請務必對照最新藥品說明書及個別病患確認。
給藥途徑
禁忌症
- Pheochromocytoma
- Normoglycemia
- Pheochromocytoma (in humans)
- Insulinoma (may stimulate insulin release)
不良反應
- Nausea
- Vomiting
- Hypokalemia
- Hypersensitivity reactions (very rare)
- Vomiting (main adverse reaction reported in humans)
- Anaphylaxis (rare)
藥物相互作用
- Anticoagulants · May have their effects increased when glucagon is concurrently administered; this effect may be delayed. Monitor for bleeding and prothrombin activity.
監測
- Blood glucose
- Serum potassium (if used other than for acute treatment)
- Blood glucose (hourly)
- Serum potassium (if prolonged infusion)
過量
Adverse effects seen with overdose include nausea, vomiting, diarrhea, gastric hypotonicity and, possibly, hypokalemia. * Because glucagon's elimination half-life is so short (around 10 minutes in humans), treatment may not be necessary and would be symptomatic in nature. * If the patient is also receiving beta-blockers, greater increases in blood pressure and heart rate may be seen.
VetSheet 藥物參考供持牌獸醫專業人員作臨床決策輔助之用,不能取代專業判斷或廠方最新藥品說明書。