醋酸可的松
**醋酸可的松 (Cortisone acetate)** 是一種口服皮質類固醇，同時具有**糖皮質素**和**鹽皮質素**的作用。 主要臨床重點： * **前驅藥特性**：它在體內無生物活性，必須經由肝臟轉化為皮質醇 (cortisol) 才能發揮作用。 * **艾迪森氏症管理**：可作為犬隻腎上腺皮質功能低下症（艾迪森氏症）口服治療中，替代培尼皮質醇 (prednisolone) 的潛在選擇。由於它同時提供糖皮質素和鹽皮質素活性，可能減少主要鹽皮質素藥物（如氟氫可的松）的劑量需求，進而降低整體治療成本。 * **爭議性**：在獸醫學中並不常用，且其增加的鹽皮質素活性是否比標準培尼皮質醇療法具有顯著的臨床益處，在內分泌學家中仍有爭議。 * **安全性**：當用於艾迪森氏症的生理替代劑量時，通常耐受性極佳。若使用超生理劑量，則會引發典型的皮質類固醇副作用（例如：多渴/多尿/多食、喘息、免疫抑制）。
作用機制: Cortisone acetate is a prodrug. Upon oral absorption, it undergoes first-pass hepatic metabolism where the enzyme **11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1)** converts it into the active hormone, **cortisol**. * **Glucocorticoid Action**: Cortisol diffuses across cell membranes and binds to cytosolic **glucocorticoid receptors (GR)** → the receptor-ligand complex translocates to the nucleus → binds to glucocorticoid response elements (GREs) on DNA → alters gene transcription (transactivation of anti-inflammatory proteins and transrepression of pro-inflammatory cytokines). * **Mineralocorticoid Action**: Cortisol also binds to **mineralocorticoid receptors (MR)** in the distal renal tubules → promotes sodium retention and potassium excretion, which is critical for patients with hypoadrenocorticism.
各物種劑量
- Long-term treatment of hypoadrenocorticism (changeover period) · 0.5-1 mg/kg PO q12-24h · PO · q12-24h · Initial stabilization · Used initially with a semi-selective mineralocorticoid (fludrocortisone).
- Long-term treatment of hypoadrenocorticism (maintenance) · 0.5 mg/kg PO q12-24h · PO · q12-24h · Long-term · Provides adequate additional glucocorticoid supplementation once 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 cortisone acetate
- Systemic fungal infections (general corticosteroid contraindication)
不良反應
- Vomiting
- Inappetence
- Diarrhea
- Hypersensitivity reactions (rare)
- Polyuria/Polydipsia/Polyphagia (at supra-physiologic doses)
- Panting (at supra-physiologic doses)
- Immunosuppression (at supra-physiologic doses)
藥物相互作用
- Amphotericin B · Concomitant use may cause hypokalemia; risk of CHF and cardiac enlargement reported in humans.
- Aspirin · Glucocorticoids may reduce salicylate blood levels and increase risk for GI ulceration/bleeding.
- Diuretics, Potassium-Depleting (e.g., furosemide, thiazides) · Concomitant administration may cause hypokalemia.
- Estrogens · May potentiate the effects of hydrocortisone/glucocorticoids.
- Insulin and Antidiabetic Agents · Insulin requirements may increase due to glucocorticoid-induced insulin resistance.
- Mitotane · May alter steroid metabolism; higher doses of steroids may be needed to treat mitotane-induced adrenal insufficiency.
- NSAIDs · Increased risk of gastrointestinal ulceration and bleeding.
- Vaccines (Live attenuated) · Virus replication may be augmented if given at immunosuppressive doses; diminished immune response to killed vaccines/toxoids.
- Warfarin · May affect INR values; requires monitoring.
監測
- Weight, appetite, signs of edema
- Serum and/or urine electrolytes (Na+, K+)
- Total plasma proteins, albumin
- Blood glucose
- Growth and development in young animals
- ACTH stimulation test (Note: Cortisone cross-reacts with cortisol assays; must test before administration)
過量
Acute ingestion is rarely a clinical problem, and severe clinical effects are unlikely with a single acute overdose. However, neuropsychiatric effects can occur. Cardiac arrhythmias and anaphylaxis are theoretically possible but very rare. Treatment is generally supportive.
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