VetSheet

非那雄胺

Finasteride

4-azasteroid synthetic compound

5-α還原酶抑制劑PO狗雪貂

別名: Proscar · Propecia · finasteridum · MK-0906 · MK-906

由 VetSheet 獸醫團隊審訂更新於 2026年4月5日本內容以實證獸醫文獻為本

0.1-0.5 mg/kgPO· once daily
— 🐕

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。

各物種劑量

🌎 NA — North America🌍 EU — Europe

狗

適應症劑量途徑頻次療程地區
Benign prostatic hyperplasia0.1-0.5 mg/kgPOonce daily—🌎 NA
Benign prostatic hyperplasia<15 kg: 1.5 mg (approx. 1/3 of a 5 mg tablet); 15-30 kg: 2.5 mg (1/2 tablet); >30 kg: 5 mg (one tablet)POdaily—🌎 NA
Benign prostatic hypertrophy5 mg per dogPOq24hExtended treatment course (<8 weeks) may be required for full efficacy🌍 EU
  • Benign prostatic hyperplasia: for a 10-50 kg dog, one 5 mg tablet daily
  • Benign prostatic hypertrophy: Alternative to castration. Use when delmadinone or osaterone are not appropriate.

雪貂

適應症劑量途徑頻次療程地區
Adjunctive treatment of adrenal disease5 mg (total dose)POonce daily—🌎 NA
  • Adjunctive treatment of adrenal disease: tablet

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。

正在為病患診症？VetSheet 的 AI 會把藥物、劑量與療程直接寫入結構化診症筆記。了解 VetSheet 如何運作

概覽

非那雄胺（Finasteride）是一種合成的4-氮雜類固醇化合物，作為5-α還原酶的競爭性特異性抑制劑。

在獸醫學中，它主要用於未絕育雄性犬的​良性前列腺增生（BPH）​的內科治療。對於高價值的種犬而言，它提供了一種極佳的替代外科閹割的方案，因為它能在不顯著影響生育能力或循環睪酮濃度的情況下縮小前列腺體積。

此外，非那雄胺也作為仿單標示外使用（off-label use），用於雪貂​腎上腺疾病​的輔助治療，幫助控制受影響雄性雪貂因雄性激素驅動的臨床症狀（如前列腺腫大和尿道阻塞）。

作用機制

Finasteride specifically and totally inhibits the intracellular enzyme 5-alpha-reductase (predominantly Type II).

  • Pathway: Testosterone → (via 5-alpha-reductase) → ​Dihydrotestosterone (DHT)​

DHT is a highly potent androgen and is the primary hormone responsible for the development and enlargement of the prostate gland. By blocking this conversion, finasteride significantly reduces DHT concentrations in the prostate, liver, and skin. This leads to prostatic involution and a reduction in clinical signs of BPH. Because it does not directly block testosterone or its receptors, normal testosterone-dependent functions (such as spermatogenesis and libido) are largely preserved.

安全性與警告

禁忌症

  • Hypersensitivity to finasteride
  • Sexually developing animals
  • Females (especially pregnant females)
  • Sexually-developing dogs
  • Breeding dogs (due to secretion in semen and teratogenic potential)

不良反應

  • Decreased libido
  • Decreased ejaculate volume
  • Impotence (rare/mild)
  • Secreted into semen
  • Causes fetal anomalies (teratogenic)

注意事項

WARNING: Finasteride is highly teratogenic. Pregnant women or women who may become pregnant must exercise extreme caution.

  • Hepatic Impairment: Use with caution in patients with significant hepatic impairment as metabolism of the drug may be reduced.
  • Patient Selection: Finasteride should be used in adult males only; do not use in sexually developing animals.
  • Females: Not indicated for use in females. FDA Category X for use during pregnancy in humans (demonstrates fetal abnormalities).

藥物相互作用

Anticholinergic drugs

May precipitate or aggravate urinary retention thereby negating the effects of the drug when used for BPH

監測

  • Prostate exam (to evaluate efficacy and reduction in size)
  • Prostate size (via palpation or ultrasound)
  • Resolution of clinical signs (e.g., tenesmus, dysuria, hematuria)

藥物動力學

半衰期

狗approx. 6 hours (extrapolated from human data)

吸收

Absorbed after oral administration; in humans about 65% is bioavailable. The presence of food does not affect absorption.

分佈

Distributed across the blood-brain barrier and is found in seminal fluid. In humans, about 90% is bound to plasma proteins.

代謝

Metabolized in the liver.

排除

Metabolites are excreted in the urine and feces. In humans, a single daily dose suppresses DHT concentrations for 24 hours.

過量

Limited information is available regarding acute toxicity. Mild gastrointestinal effects (such as vomiting or diarrhea) may be noted in the event of an overdose. Supportive care is recommended.

可用產品

劑型

  • Oral tablets
  • Oral: 5 mg tablet

人用標示

  • Finasteride Oral Tablets: 1 mg & 5 mg; Proscar®, Propecia® (Merck); generic
  • Proscar 5 mg tablets

各地核准狀態

European Union✗ 未核准處方藥EMA

Not authorized for veterinary use. Should only be used under the cascade when delmadinone or osaterone are not appropriate.

United Kingdom✗ 未核准處方藥VMD

POM (Prescription Only Medicine). Not authorized for veterinary use; cascade use only.

暫無法規資料: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU

儲存與穩定性

Store tablets below 30°C in tight containers and protected from light.

飼主須知

​孕婦的嚴重警告​：懷孕或可能懷孕的婦女​絕對不可​接觸壓碎或破損的藥片。其活性成分可透過皮膚吸收，並導致男性胎兒出現嚴重的先天性缺陷。

  • ​需要耐心​：在確定療效之前，治療可能需要持續一段較長的時間（數週至數月）。必須嚴格遵守規律給藥才能獲得成功。
  • ​終身承諾​：一旦停藥，前列腺通常會再次開始生長。除非犬隻進行絕育，否則通常需要長期治療。
  • ​繁殖考量​：選擇此藥物通常是因為它能保留種犬的生育和繁殖能力，儘管可能會出現射精量輕微減少的情況。

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