納曲酮
Naltrexone
Naltrexone hydrochloride
別名: ReVia · Vivitrol · EN-1639A · Naltrexone HCl
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 |
|---|---|---|---|---|---|
| As adjunctive therapy in behavior disorders (tail chasing or excessive licking) | 1-2 mg/kg | PO | daily | Long-term therapy may be required | 🌎 NA |
| As adjunctive therapy in behavior disorders | 2-5 mg/kg | PO | once daily | — | 🌎 NA |
| As adjunctive therapy in behavior disorders | 1-2.2 mg/kg | PO | q8-12h | — | 🌎 NA |
| For the adjunctive treatment of acral pruritic dermatitis | 2.2 mg/kg | PO | once daily | one-month trial | 🌎 NA |
- As adjunctive therapy in behavior disorders (tail chasing or excessive licking): First give 0.01 mg/kg SC of naloxone to determine if narcotic antagonists may be effective, if so give naltrexone.
- For the adjunctive treatment of acral pruritic dermatitis: Some dogs exhibit drowsiness and minor changes in behavior. 50-60% of patients have benefited. Expense is of concern.
貓
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| As adjunctive therapy in behavior disorders | 25-50 mg/cat | PO | q24h | — | 🌎 NA |
- As adjunctive therapy in behavior disorders: Note: has a bitter taste
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。
概覽
納曲酮是一種合成的長效純鴉片類受體拮抗劑。雖然結構上與納洛酮（naloxone）相似，但其口服生物利用度更高，作用時間更長。
在獸醫學中，它主要作為標示外用藥，用於強迫性行為障礙的輔助治療，例如：
- 肢端舔舐性皮膚炎（舔舐肉芽腫）
- 追尾行為
- 吸吮側腹行為
- 其他自我傷害或刻板行為
臨床要點：其應用於行為醫學的原理，源於刻板行為會刺激內源性鴉片類物質（腦內啡）釋放，進而強化該行為的假說。透過阻斷這些受體，納曲酮消除了內在的「獎勵」機制，有助於消除強迫行為。
作用機制
Naltrexone acts as a competitive antagonist at opioid receptors, with the highest affinity for μ (mu) receptors, followed by κ (kappa) and δ (delta) receptors.
- Mechanism in Behavior Disorders: Compulsive behaviors → Release of endogenous endorphins → Binding to μ-receptors → Reinforcement/Analgesia.
- Naltrexone blocks these receptors → Prevents endorphin binding → Eliminates the auto-reinforcing reward loop of the stereotypic behavior.
安全性與警告
不良反應
- Drowsiness
- Minor changes in behavior
- Elevated hepatic enzymes (AST, ALT)
注意事項
Naltrexone may cause increases in hepatic function tests (e.g., AST, ALT). It can interfere with some enzymatic assays (though it does not interfere with TLC, GLC, or HPLC methods for urinary opiates). The drug has a bitter taste, which may complicate oral administration, particularly in cats.
藥物相互作用
May antagonize the effects of these agents, including respiratory depression and analgesia.
Naltrexone may reduce the hypotensive and bradycardic effects of clonidine.
Naltrexone may increase the CNS effects of yohimbine (anxiety, tremors, nausea, palpitations) and increase plasma cortisol levels.
監測
- Clinical efficacy (reduction in stereotypic behaviors)
- Liver enzymes (AST, ALT) if using very high doses with prolonged therapy
過量
Specific overdosage information is not provided in the monograph. However, as an opioid antagonist, massive overdoses could theoretically cause dysphoria or precipitate withdrawal in opioid-dependent patients. Monitor liver enzymes if very high doses are ingested.
可用產品
劑型
- Oral tablets
- Powder for suspension extended-release injection
人用標示
- Naltrexone HCl Oral Tablets: 50 mg; ReVia (Duramed); generic
- Naltrexone HCl Powder for Suspension Extended-Release Injection: 380 mg/vial in single-use vials w/4 mL diluent; Vivitrol (Alkermes)
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
Naltrexone tablets should be stored at room temperature in well-closed containers.
飼主須知
服藥順從性是關鍵：為了確保藥物有效，請務必嚴格遵守獸醫指示的給藥時間表。
- 綜合治療方法：單靠藥物通常無法完全治癒。通常需要結合額外的行為矯正技術和環境豐富化，才能成功緩解寵物的症狀。
- 給藥技巧：此藥物具有非常明顯的苦味，這使得餵食貓咪特別困難。建議將藥物藏在極具吸引力的零食中，或將其放入空的明膠膠囊內餵食。
- 注意事項：有些寵物可能會出現輕微的嗜睡或行為上的細微改變。如果這些副作用很嚴重或讓您感到擔憂，請聯繫您的獸醫。
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。