鮭魚降鈣素
鮭魚降鈣素是一種合成的多肽激素，在獸醫學中主要用於控制嚴重的**高血鈣症**（例如：膽鈣化醇殺鼠劑中毒、頂漿腺肛門囊腺癌或淋巴癌引起）以及爬行動物的營養性繼發性甲狀旁腺功能亢進（NSHP）。它也可作為嚴重骨痛的輔助治療。 * **臨床要點**：使用鮭魚降鈣素是因為其效力比哺乳動物（人類）降鈣素高約50倍，且作用時間更長。 * **限制**：其臨床實用性常因昂貴的費用和快速產生**快速耐受性（Tachyphylaxis）**（受體下調）而受限，這意味著在連續治療數天後通常會失去療效。 * **警告**：請勿將降鈣素（降低血鈣）與骨化三醇（升高血鈣）混淆。
作用機制: Calcitonin exerts a multitude of physiologic effects to rapidly lower serum calcium levels: * **Bone**: Binds directly to **calcitonin receptors** on osteoclasts → profoundly inhibits osteoclastic bone resorption → decreases the release of calcium and phosphorus from bone into the extracellular fluid. * **Kidneys**: Acts on the renal tubules → reduces tubular reabsorption of calcium, phosphate, sodium, magnesium, potassium, and chloride → promotes their renal excretion. * **Gastrointestinal Tract**: Increases jejunal secretion of water, sodium, potassium, and chloride (but notably not calcium).
各物種劑量
- Hypervitaminosis D (toxicity)/hypercalcemia · 4-8 Units/kg · SC · two to three times a day · Effects are short-lived and multiple treatments are required.
- Hypervitaminosis D (toxicity)/hypercalcemia · 4-6 Units/kg · SC · q2-3 hours · until serum calcium levels are normalized
- Adjunctive therapy if fluid deficit replacement, saline diuresis, furosemide and prednisone have failed to control calcium · 4 Units/kg IV, then 4-8 Units/kg SC · IV, then SC · q12-24h
- Hypervitaminosis D (toxicity)/hypercalcemia · 4-6 Units/kg · SC · q8-12h
- Hypercalcemia (Green iguanas) · 1.5 Units/kg · SC · q8h · for several weeks if necessary · In combination with fluid therapy
- Nutritional secondary hyperparathyroidism (NSHP) · 50 Units/kg · IM · once weekly · for 2-3 doses · Use if reptile is not hypocalcemic.
- Nutritional secondary hyperparathyroidism (NSHP) · 50 Units/kg · IM · weekly · for 2-3 doses · Correct husbandry problems and correct hypocalcemia with calcium and vitamin D first. Once calcium level is normal and patient is on oral calcium supplementation (usually about 7 days after starting therapy) give calcitonin. Supportive care can be tapered off once patient becomes stable.
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
- Hypersensitivity to calcitonin
- Patients with a history of hypersensitivity to other proteins may be at risk
不良反應
- Anorexia
- Vomiting
- Hypocalcemia (with overmedication)
- Diarrhea
- Injection site pain and swelling
- Redness
- Peripheral paresthesias (reported in humans)
- Allergic reactions (rare)
- Tachyphylaxis (resistance to therapy over time)
藥物相互作用
- Vitamin D analogs · May interfere with the efficacy of calcitonin
- Calcium products · May interfere with the efficacy of calcitonin
監測
- Serum Calcium
過量
Very limited data is available. Nausea and vomiting have been reported after accidental overdose injections. Chronic overdosing can lead to severe **hypocalcemia**.
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。