異維A酸 / 異維甲酸
Isotretinoin
13-cis-retinoic acid
別名: Claravis · Amnesteem · Accure · Accutin · Curatane · Isoacne · Isohexal · Isotrex · Liderma · Nimegen · Oratane · Procuta · Roaccutane · Roacutan · Stiefotrex · isotretinoinum · 13-cis-retinoic acid · Ro4-3780
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
劑量為合格獸醫專業人員的臨床參考。請務必對照最新仿單及個別病患確認。
各物種劑量
🌎 NA — North America🌍 EU — Europe
狗
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Sebaceous adenitis when more conservative treatments have failed | 1 mg/kg PO q12h for one month; if improvement is noted reduce dose to 1 mg/kg PO once daily; long-term goal is to treat with either 1 mg/kg PO every other day or 0.5 mg/kg once daily | PO | q12h initially, then q24h or q48h | Long-term | 🌎 NA |
| Sebaceous adenitis | 1-3 mg/kg PO once a day to twice daily | PO | q12-24h | — | 🌎 NA |
| Schnauzer comedo syndrome | 1 mg/kg once daily or divided q12h PO | PO | q12-24h | — | 🌎 NA |
| Sebaceous adenitis in poodles; granulomatous sebaceous adenitis in viszlas | 1-2 mg/kg once daily or divided q12h PO | PO | q12-24h | — | 🌎 NA |
| Epitheliotrophic lymphoma, cutaneus lymphoma | 2 mg/kg once daily or divided q12h PO | PO | q12-24h | — | 🌎 NA |
| Schnauzer comedo syndrome, sebaceous adenitis in poodles, ichthyosis, keratocanthoma, epitheliotropic lymphoma, and sebaceous gland hyperplasia and adenoma | 1-3 mg/kg q12-24h PO | PO | q12-24h | — | 🌎 NA |
| Cutaneous lymphosarcoma | Isotretinoin at 3-4 mg/kg PO daily. Prednisone (1 mg/kg/day) may be useful to alleviate pruritus. Lomustine at 50 mg/m2 q21-30 days may be effective | PO | q24h | — | 🌎 NA |
- Cutaneous lymphosarcoma: See lomustine monograph for more information
貓
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Feline acne | 5 mg/kg PO once daily | PO | q24h | — | 🌎 NA |
| Feline acne | 10 mg per cat once daily PO | PO | q24h | — | 🌎 NA |
| Feline acne | 1-3 mg/kg q12-24h PO | PO | q12-24h | — | 🌎 NA |
| Epitheliotrophic lymphoma, cutaneus lymphoma | 10 mg/cat once daily PO | PO | q24h | — | 🌎 NA |
劑量為合格獸醫專業人員的臨床參考。請務必對照最新仿單及個別病患確認。
概覽
異維A酸 (Isotretinoin) 是一種第一代合成視黃醇類藥物（維A酸類），主要用於獸醫皮膚科，治療與角質化異常及皮脂腺功能障礙相關的嚴重疾病。
主要臨床應用：
- 犬板層狀魚鱗癬 (Canine lamellar ichthyosis)
- 皮膚T細胞淋巴瘤 (Cutaneous T-cell lymphoma)
- 皮內角化上皮瘤 (Intracutaneous cornifying epitheliomas)
- 多發性表皮包涵囊腫 (Multiple epidermal inclusion cysts)
- 雪納瑞粉刺症候群 (Comedo syndrome in Schnauzers)
- 皮脂腺炎 (Sebaceous adenitis)（特別是標準貴賓犬和維茲拉犬）
- 貓粉刺 (Feline acne)
臨床要點： 由於其對皮脂腺的顯著作用，異維A酸通常被認為是治療皮脂腺炎和雪納瑞粉刺症候群的首選視黃醇類藥物，而其他視黃醇類（如阿維A）可能更適合原發性角質化缺陷。
由於對人類具有嚴重的致畸胎風險（FDA懷孕用藥分級X級），製造商和經銷商可能會嚴格限制獸醫取得此藥物。
作用機轉
Isotretinoin acts by regulating epithelial cell proliferation and differentiation.
- Receptor Binding: Retinoids enter the cell and bind to intracellular Retinoic Acid Receptors (RARs) and Retinoid X Receptors (RXRs) → altering gene transcription.
- Sebosuppressive Effect: It significantly reduces sebaceous gland size and activity → decreasing sebum production.
- Anti-keratinization & Anti-inflammatory: Normalizes follicular desquamation (preventing comedone formation) and affects monocyte/lymphocyte function, altering cellular immune responses.
- Antimicrobial (Indirect): By altering the microenvironment of the sebaceous pore (reducing sebum), it indirectly reduces bacterial populations.
安全性與警告
禁忌症
- Pregnancy (absolute contraindication - known teratogen)
- Nursing mothers
- Hypertriglyceridemia
- Severe renal disease
- Severe hepatic disease
- Known hypersensitivity to isotretinoin
不良反應
- Dogs: Keratoconjunctivitis sicca (KCS) - most common
- Dogs: GI effects (anorexia, vomiting, diarrhea, abdominal distention)
- Dogs: CNS effects (lassitude, hyperactivity, behavioral changes, collapse)
- Dogs: Stiffness of limbs
- Dogs: Pruritus, exfoliative dermatitis, erythema of feet and mucocutaneous junctions/cheilitis
- Dogs: Polydipsia, swollen tongue
- Cats: Blepharospasm, periocular crusting, erythema
- Cats: Diarrhea
- Cats: Weight loss secondary to anorexia
注意事項
Teratogenicity: Isotretinoin is a known teratogen (FDA Category X). Major anomalies have been reported in children of women taking the medication. It is absolutely contraindicated in pregnant veterinary patients and should NOT be used in households where pregnant women are present.
Hepatic & Lipid Effects: May cause increases in serum triglycerides, cholesterol, and liver enzymes. Use with caution in patients with pre-existing hepatic or lipid disorders.
Ocular Effects: High risk of keratoconjunctivitis sicca (dry eye) in dogs; regular monitoring is required.
藥物交互作用
May cause additive toxic effects.
Isotretinoin may increase cyclosporine levels.
Use with tetracyclines may increase the potential for the occurrence of pseudotumor cerebri (cerebral edema and increased CSF pressure).
監測
- Clinical efficacy
- Liver function tests (baseline and if signs appear)
- Serum triglycerides and cholesterol
- Dogs: Schirmer Tear tests (monthly, especially in older dogs to monitor for KCS)
- Cats: Body weight (monitor for anorexia-induced weight loss)
藥物動力學
吸收
Rapidly absorbed from the gut once the capsule disintegrates. Animal studies show ~25% bioavailability, but food or milk in the gut may increase this amount. Peak absorption may require up to 2 hours.
分佈
Distributed into many tissues, but is not stored in the liver (unlike vitamin A). Crosses the placenta and is highly bound to plasma proteins. Unknown if it enters milk.
代謝
Metabolized in the liver.
排除
Excreted in the urine and feces.
過量
In a review of 147 exposures reported to the ASPCA APCC (140 dogs, 7 cats), only 5 dogs showed clinical signs, most commonly hypersalivation. Cats showed no clinical signs.
Because of the drug's potential adverse effects, gut emptying should be considered with acute overdoses when warranted. Monitor for GI upset and CNS signs.
可用產品
劑型
- Oral capsules (regular and soft gel)
人用標示
- Isotretinoin Oral Capsules: 10 mg, 20 mg, 30 mg & 40 mg (regular & soft gel) (Claravis, Amnesteem, Sotret)
各地核准狀態
暫無法規資料: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
儲存與穩定性
Capsules should be stored at room temperature in tight, light-resistant containers. The drug is photosensitive and will degrade with light exposure. Expiration dates of 2 years are assigned after manufacture.
飼主須知
重大安全警告： 異維A酸會導致嚴重的出生缺陷。孕婦或可能懷孕的女性絕對不可接觸此藥物。 強烈建議不要在有孕婦的家庭中使用此藥物。
- 給藥方式： 請保持一致的給藥方式（固定與食物/牛奶一起餵食，或固定空腹），因為飲食中的脂肪會顯著增加身體對藥物的吸收量。
- 陽光照射： 避免讓寵物長時間或過度暴露在陽光下，因為此藥物會使皮膚對紫外線更加敏感。
- 犬隻乾眼症： 此藥物經常導致犬隻出現「乾眼症」（淚液分泌減少）。請注意眼睛發紅、瞇眼或濃稠眼屎等症狀，獸醫師會定期進行淚液測試。
- 貓咪： 密切觀察是否有食慾不振和體重減輕的情況。如果您的貓咪停止進食，請立即聯繫獸醫師。
- 費用： 請注意，長期使用此藥物治療的費用可能相當昂貴。
VetSheet 藥物參考供合格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商最新仿單。