他克莫司
Tacrolimus
FK-506
別名: Protopic · Prograf · Advagraf · FK-506 · fujimycin
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
各物種劑量
此藥的劑量資料尚未收錄於 VetSheet 藥典，以下其他章節資料完整。開立處方前請參閱最新仿單。
概覽
他克莫司（FK 506）是一種強效的巨環類免疫抑制劑。在獸醫學中，主要用於局部治療免疫介導性皮膚病（如肛周瘻管和異位性皮膚炎）以及眼部治療乾眼症（KCS）。由於潛在的毒性，全身性使用較不常見，但可用於嚴重的免疫介導性疾病。
臨床提示： 對於環孢素治療無效的乾眼症病例，他克莫司通常有效。
作用機轉
Binds to the intracellular protein FKBP-12 (FK506 binding protein) → forms a complex that inhibits calcineurin (a calcium-dependent phosphatase) → prevents dephosphorylation of NF-AT (nuclear factor of activated T-cells) → inhibits transcription of IL-2 and other cytokines → profound T-lymphocyte inhibition.
安全性與警告
禁忌症
- Hypersensitivity to macrolides
- Active systemic infections
- Malignancy (for systemic use)
不良反應
- Topical: local irritation, erythema, pruritus
- Ophthalmic: mild ocular irritation
- Systemic: GI upset (vomiting, diarrhea), nephrotoxicity, neurotoxicity, secondary infections
注意事項
Warning: Avoid switching between oral brands due to narrow therapeutic index and variable bioavailability. Wear gloves when applying topical formulations to avoid inadvertent human exposure. Monitor blood levels if used systemically.
藥物交互作用
Inhibits CYP3A metabolism, significantly increasing systemic tacrolimus levels
Inhibits metabolism, increasing tacrolimus levels
Increases systemic absorption and blood levels of tacrolimus
監測
- Tear production (Schirmer Tear Test) for KCS
- Resolution of skin lesions
- Whole blood trough levels (if used orally)
- Renal and hepatic function (if used orally)
藥物動力學
半衰期
吸收
Poor and variable oral absorption. Minimal systemic absorption from intact skin, but absorption increases significantly when applied to inflamed or damaged skin.
分佈
Highly protein bound, primarily to erythrocytes and plasma proteins.
代謝
Extensively metabolized in the liver and intestines by CYP3A enzymes.
排除
Primarily excreted via the biliary/fecal route.
過量
Systemic overdose can lead to severe nephrotoxicity, neurotoxicity (tremors, seizures), and profound immunosuppression. Treatment is supportive and symptomatic. No specific antidote exists.
可用產品
劑型
- Topical: 0.03% skin ointment
- Topical: 0.1% skin ointment
- Ophthalmic: 0.02% eye drop (solution)
- Oral: various preparations
獸醫用
- Tacrolimus 0.02% eye drops (often compounded or specific veterinary brands)
人用標示
- Protopic 0.03% ointment
- Protopic 0.1% ointment
- Prograf capsules
- Advagraf capsules
各地核准狀態
POM (Prescription Only Medicine). Often used off-label under the cascade.
POM (Prescription Only Medicine). Often used off-label under the cascade.
暫無法規資料: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
儲存與穩定性
Store at room temperature away from moisture and heat. Keep tubes and bottles tightly closed.
飼主須知
為寵物塗抹藥膏或點眼藥水時請戴上手套。使用後請徹底洗手。請勿讓其他寵物舔舐治療部位。
警告： 如果使用口服藥物，請勿在未諮詢獸醫的情況下更換品牌，因為不同品牌的吸收率不同。孕婦應盡量避免接觸此藥物。
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