達那唑
達那唑是一種**合成雄性激素**。在獸醫學中，主要作為輔助免疫調節劑，用於治療犬貓的**免疫介導性溶血性貧血 (IMHA)** 和 **免疫介導性血小板減少症 (ITP)**。由於其療效不可預測且起效緩慢，通常在對糖皮質激素等標準療法產生抗藥性時才作為挽救療法使用。
作用機制: Danazol possesses weak androgenic, anabolic, and antiestrogenic properties. Its immunomodulatory effects are achieved through several mechanisms: * **Fc Receptor Modulation**: Reduces the affinity of autoantibodies for the **mononuclear phagocytic system Fc receptors** → decreases the macrophage-mediated destruction of antibody-coated red blood cells and platelets. * **Steroid-Binding Globulin Competition**: Competes with glucocorticoids for binding sites on **corticosteroid-binding globulin (CBG)** → increases the fraction of free, pharmacologically active glucocorticoids in circulation, enhancing their efficacy. * **Pituitary-Ovarian Axis Suppression**: Inhibits the synthesis of sex steroids and binds directly to sex steroid receptors in target tissues.
各物種劑量
- Adjunctive treatment of immune-mediated hemolytic anemia · 5 mg/kg PO twice daily · PO · q12h
- Adjunctive treatment of immune-mediated hemolytic anemia (non-regenerative forms) · 5 mg/kg PO three times daily. · PO · q8h · Used to reduce the dose of glucocorticoids needed for long-term therapy.
- Adjunctive treatment of immune-mediated hemolytic anemia or thrombocytopenia · 5 mg/kg PO 2-3 times per day · PO · q8-12h · Rarely helpful. Costly and has limited effectiveness.
- Adjunctive treatment of immune-mediated hemolytic anemia or thrombocytopenia · 10 mg/kg/day PO. Once anemia improves, corticosteroids may be slowly tapered and eventually DC'd. When remission maintained by danazol alone, may lower to 5 mg/kg/day. Slowly taper after 2-3 months of normal hemograms with frequent monitoring of hemograms. · PO · q24h · Long-term · Initially given in addition to prednis(ol)one.
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
- Pregnancy (Teratogenic - FDA Category X)
- Nursing/breastfeeding
- Severe cardiac function impairment
- Severe renal function impairment
- Severe hepatic function impairment
- Undiagnosed abnormal vaginal bleeding
不良反應
- Hepatotoxicity (rare but significant in dogs)
- Virilization in females
- Weight gain
- Lethargy
- Edema
- Testicular atrophy
- Hirsutism
- Alopecia
- Vaginitis (reported in humans)
藥物相互作用
- Cyclosporine · May significantly increase cyclosporine levels
- Insulin · By affecting carbohydrate metabolism, danazol may affect insulin requirements (doses may need to be increased) in diabetic patients
- Warfarin · Concomitant use may enhance the anticoagulant effect as danazol may decrease the synthesis of procoagulant factors in the liver
監測
- Efficacy (CBC, platelets, reticulocyte count)
- Hepatic function (baseline and at regular intervals while on therapy)
過量
No specific information was located regarding acute toxicity in animals. Significant overdoses should initially be handled by contacting an animal poison control center and initiating gut emptying protocols (emesis or gastric lavage, followed by activated charcoal) when applicable.
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。