ダナゾール
ダナゾールは**合成アンドロゲン**です。獣医学では主に、犬および猫の**免疫介在性溶血性貧血（IMHA）**や**免疫介在性血小板減少症（ITP）**の補助的免疫調節薬として使用されます。効果が予測しにくく発現が遅いため、通常はグルココルチコイドなどの標準治療に抵抗性を示す場合の救済療法として使用されます。
作用機序: 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.
動物種別の用量
- 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.
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
- Pregnancy (Teratogenic - FDA Category X)
- Nursing/breastfeeding
- Severe cardiac function impairment
- Severe renal function impairment
- Severe hepatic function impairment
- Undiagnosed abnormal vaginal bleeding
有害事象
- Hepatotoxicity (rare but significant in dogs)
- Virilization in females
- Weight gain
- Lethargy
- Edema
- Testicular atrophy
- Hirsutism
- Alopecia
- Vaginitis (reported in humans)
薬物相互作用
- 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
モニタリング
- Efficacy (CBC, platelets, reticulocyte count)
- Hepatic function (baseline and at regular intervals while on therapy)
過量投与
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 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。