米勃酮
米勃酮（Mibolerone）是一種強效的**雄激素、同化類固醇及抗促性腺激素** 19-去甲類固醇藥物。 * 過去以 Cheque® Drops 品牌銷售，目前市面取得不易，主要透過調劑藥局取得，在美國被列為**第三級管制藥品**。 * **臨床用途**包括母犬的發情抑制、假孕及嚴重溢乳症的治療。 > **警告：** 米勃酮對貓的治療指數極窄且具有高度毒性，**絕對不可**用於貓咪患者。
作用機制: Mibolerone exerts its effects via a **negative feedback mechanism** on the anterior pituitary gland. * **Blocks luteinizing hormone (LH)** release → prevents follicular maturation → inhibits ovulation and corpus luteum development. * The net result is the suppression of the estrous cycle if administered prior to (up to 30 days) the onset of proestrus. * After discontinuation, the next estrus typically occurs within 7-200 days (average 70 days).
各物種劑量
- Suppression of estrus · 0.5-11 kg: 30 micrograms (0.3 mL) PO per day; 12-22 kg: 60 micrograms (0.6 mL) PO per day; 23-45 kg: 120 micrograms (1.2 mL) PO per day; >45 kg: 180 micrograms (1.8 mL) PO per day. German shepherds or German shepherd crosses: 180 micrograms (1.8 mL) PO per day; regardless of weight · PO · q24h · Treatment must begin at least 30 days prior to proestrus · If dog comes into estrus after receiving the drug for 30 or more days, stop drug and determine that the dog is not pregnant before resuming therapy. If owner compliance has been determined, increase dosage by 20-50%.
- Pseudocyesis (false pregnancy) · 10 times the dosage listed above for suppression of estrus · PO · q24h · 5 days
- Pseudocyesis (false pregnancy) · 16 micrograms/kg · PO · q24h · 5 days
- Cystic endometrial hyperplasia (CEH) · 30 micrograms/25lb. body weight · PO · q24h · 6 months
- Treatment of severe galactorrhea · 8-18 micrograms/kg · PO · q24h · 5 days · Once discontinued, prolactin may surge and galactorrhea resume.
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
- Perianal adenoma or perianal adenocarcinoma
- Other androgen-dependent neoplasias
- Pregnant or lactating bitches
- Patients with ongoing or a history of liver or kidney disease
- Bedlington Terriers
- Cats
不良反應
- Premature epiphyseal closure (in prepuberal females)
- Clitoral enlargement / hypertrophy
- Vaginitis / Vulvovaginitis
- Increased body odor
- Abnormal behavior (e.g., riding/mounting behavior)
- Urinary incontinence
- Voice deepening
- Enhanced clinical signs of seborrhea oleosa
- Epiphora (tearing)
- Hepatic changes (intranuclear hyaline bodies) and rare hepatic dysfunction
- Increased kidney weight
- Fatalities, thyroid dysfunction, and pancreatic dysfunction (in cats)
藥物相互作用
- Phenytoin · Increased seizure activity has been reported in a dog previously controlled on phenytoin.
- Progestins · Should generally not be used concurrently.
- Estrogens · Should generally not be used concurrently.
監測
- Clinical signs of estrus
- Liver function tests (baseline, annual, or as needed)
- Physical examination of genitalia
過量
In dogs, the drug did not cause death in doses up to 30,000 micrograms/kg/day when administered to beagles for 28 days. In cats, dosages as low as 120 micrograms/day have resulted in fatalities.
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。