グルカゴン
**グルカゴン**は肵臓のα2細胞から分泌されるポリペプチドホルモンです。獣医療では主に、インスリノーマやインスリン過剰投与による重度の低血糖の治療に使用されます。また、乳牛の脂肪肝症候群の治療にも可能性が示されています。
作用機序: 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).
動物種別の用量
- 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
用量は獣医療従事者向けの臨床リファレンスです。必ず最新の添付文書と個々の患者で確認してください。
投与経路
禁忌
- Pheochromocytoma
- Normoglycemia
- Pheochromocytoma (in humans)
- Insulinoma (may stimulate insulin release)
有害事象
- Nausea
- Vomiting
- Hypokalemia
- Hypersensitivity reactions (very rare)
- Vomiting (main adverse reaction reported in humans)
- Anaphylaxis (rare)
薬物相互作用
- Anticoagulants · May have their effects increased when glucagon is concurrently administered; this effect may be delayed. Monitor for bleeding and prothrombin activity.
モニタリング
- Blood glucose
- Serum potassium (if used other than for acute treatment)
- Blood glucose (hourly)
- Serum potassium (if prolonged infusion)
過量投与
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 の薬剤リファレンスは、獣医療従事者向けの臨床意思決定支援を目的としており、専門的判断やメーカーの最新添付文書に代わるものではありません。