醋酸奧曲肽
**醋酸奧曲肽 (Octreotide acetate)** 是一種人工合成的長效八肽化合物，為天然體抑素 (somatostatin) 的類似物。在獸醫學中，主要作為神經內分泌腫瘤（如犬和雪貂的**胰島素瘤**及**胃泌素瘤**）的輔助治療。 主要臨床重點： - **胰島素瘤管理**：透過抑制腫瘤性β細胞釋放胰島素來幫助穩定血糖，但由於受體表現的差異，療效因個體而異。 - **乳糜胸**：越來越多被標示外使用於控制乳糜性胸水，其機制為減少內臟血流及淋巴液的產生。 - **限制**：需要每天多次皮下注射，且對於大型犬而言費用可能相當昂貴。對貓的肢端肥大症無效。
作用機制: **Octreotide** mimics natural somatostatin by binding to **somatostatin receptors (SSTRs)** on target cells. Mechanism pathway: **Octreotide** → binds to **SSTRs** (G-protein coupled receptors) → inhibits **adenylyl cyclase** → decreases intracellular **cAMP** → reduces calcium influx → inhibits exocytosis of secretory vesicles. This leads to the potent suppression of multiple endocrine and exocrine secretions, including: - **Insulin** and **glucagon** from the pancreas. - **Gastrin**, **secretin**, and **motilin** from the gastrointestinal tract. - **Growth hormone (GH)** from the anterior pituitary. *Note*: Humans possess 5 SSTR subtypes, whereas dogs primarily express one, which may explain the variable clinical response seen in canine insulinoma patients.
各物種劑量
- Adjunctive treatment of chylothorax · 10-20 micrograms/kg · SC · three times a day · 2-3 weeks · Prolonged treatment should be discouraged because people treated for longer than 4 weeks are at risk for gallstones.
- Medical treatment of insulinoma (particularly in patients refractory to or unable to tolerate other medical or surgical therapy) · 1-2 micrograms/kg · SC · 2-3 times a day
- Medical treatment of insulinoma (beta cell tumor) particularly in patients refractory to or unable to tolerate other medical or surgical therapy · 10-40 micrograms (total dose per dog) · SC · 2-3 times a day · Used in combination with dietary, glucocorticoid, and diazoxide treatment.
- Medical treatment of insulinoma · 2-4 micrograms/kg · SC · q8-12h · Further studies needed to determine octreotide's efficacy and safety.
- Adjunctive treatment of gastrinoma · 2-20 micrograms/kg · SC · three times daily · With omeprazole.
- Adjunctive treatment of chylothorax · 10-20 micrograms/kg · SC · three times a day · 2-3 weeks · Prolonged treatment should be discouraged because people treated for longer than 4 weeks are at risk for gallstones.
劑量為合格獸醫專業人員的臨床參考。請務必對照最新藥品仿單及個別病患確認。
給藥途徑
禁忌症
- Known hypersensitivity to octreotide
不良反應
- Gastrointestinal upset
- Decreased dietary fat absorption
- Biliary sludging or gallstones (with prolonged use)
- Injection site pain
藥物相互作用
- Beta-blockers · May cause additive bradycardic effects
- Bromocriptine · May increase oral bioavailability
- Calcium-channel blockers · May cause additive bradycardic effects
- Cyclosporine · May reduce cyclosporine levels
- Diuretics · May enhance fluid/electrolyte imbalances
- Food · May reduce fat absorption
- Insulin, oral hypoglycemics · Octreotide can inhibit insulin
- Quinidine · May reduce the quinidine clearance
監測
- Blood glucose (for insulinoma treatment)
- Clinical efficacy
過量
Serious adverse effects are unlikely with acute overdose. In humans, subjects have received up to 120 mg IV over 8 hours with no untoward effects. Monitor for profound hypoglycemia or gastrointestinal distress and provide supportive care if needed.
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。