乙醯半胱胺酸
Acetylcysteine
N-acetyl-L-cysteine
別名: Mucomyst · Acetadote · NAC · ACC · Ilube · Parvolex · Fluimucil · N-acetylcysteine · N-acetyl-L-cysteine · 5052 acetylcysteinum · NSC-111180
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 |
|---|---|---|---|---|---|
| Acetaminophen toxicity | 140 mg/kg PO loading dose, followed by 70 mg/kg PO q6h | PO | q6h | For 7 treatments (up to 12-17 doses for massive ingestions) | 🌎 NA |
| Acetaminophen toxicity | 150 mg/kg PO or IV initially, then 50 mg/kg q4h | PO/IV | q4h | For 17 additional doses | 🌎 NA |
| Acetaminophen toxicity | 140 mg/kg PO loading dose, then 70 mg/kg PO every 6 hours | PO | q6h | For 7 treatments | 🌎 NA |
| Phenol toxicity | 140 mg/kg PO or IV initially, then 50 mg/kg q4h | PO/IV | q4h | For 3 days | 🌎 NA |
| Hepatotoxicity secondary to xylitol poisoning | 140-280 mg/kg loading dose IV or PO; followed by 70 mg/kg four times daily | IV/PO | q6h | — | 🌎 NA |
| Degenerative myelopathy (anecdotal) | 25 mg/kg PO q8h for 2 weeks, then q8h every other day | PO | q8h | Indefinitely (every other day after 2 weeks) | 🌎 NA |
| Mucolytic | nebulize 50 mg as a 2% (dilute with saline) solution over 30-60 min or instil directly into the trachea 1-2 ml of a 20% solution | Nebulization/Intratracheal | prn | As needed | 🌍 EU |
| Paracetamol poisoning | 140-280 mg/kg diluted to a 5% solution using 5% dextrose by slow i.v. infusion over 15-20 min, followed by further slow infusions of 70 mg/kg (similarly diluted) every 6 hours | IV | q6h | for at least 7 doses | 🌍 EU |
| KCS | 1 drop of the ophthalmic solution | topical | q6-8h | As directed | 🌍 EU |
- Acetaminophen toxicity: Dilute to 5% in dextrose or sterile water. May also be given slow IV over 15-20 minutes. Wait 2-3 hours after activated charcoal if giving PO.
- Phenol toxicity: May be partially effective to reduce hepatic and renal injury.
- Hepatotoxicity secondary to xylitol poisoning: Used as part of a comprehensive protocol including vitamin K, plasma, SAMe, vitamin E, and silymarin.
- Degenerative myelopathy (anecdotal): Dilute 20% solution to 5% with chicken broth. Used in conjunction with aminocaproic acid. Note: No treatment has been shown to be effective in published trials.
- Mucolytic: Dilute with saline for nebulization.
- Paracetamol poisoning: Administer after inducing emesis if appropriate (within 2 hours of ingestion). IV preferred for serious intoxications. Can be given PO but must be diluted to improve palatability.
- KCS: Rarely used now for this indication.
貓
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Acetaminophen toxicity | 140 mg/kg PO loading dose, followed by 70 mg/kg PO four times daily (q6h) | PO | q6h | For 7 treatments (up to 12-17 doses for massive ingestions) | 🌎 NA |
| Phenol toxicity | 140 mg/kg PO or IV initially, then 50 mg/kg q4h | PO/IV | q4h | For 3 days | 🌎 NA |
| Adjunctive treatment of hepatic lipidosis | 140 mg/kg IV over 20 minutes, then 70 mg/kg IV q12h | IV | q12h | — | 🌎 NA |
| Mucolytic | nebulize 50 mg as a 2% (dilute with saline) solution over 30-60 min or instil directly into the trachea 1-2 ml of a 20% solution | Nebulization/Intratracheal | prn | As needed | 🌍 EU |
| Paracetamol poisoning | 140-280 mg/kg diluted to a 5% solution using 5% dextrose by slow i.v. infusion over 15-20 min, followed by further slow infusions of 70 mg/kg (similarly diluted) every 6 hours | IV | q6h | for at least 7 doses | 🌍 EU |
| KCS | 1 drop of the ophthalmic solution | topical | q6-8h | As directed | 🌍 EU |
- Acetaminophen toxicity: Dilute to 5% in dextrose or sterile water. May also be given slow IV over 15-20 minutes. Wait 2-3 hours after activated charcoal if giving PO.
- Phenol toxicity: May be partially effective to reduce hepatic and renal injury.
- Adjunctive treatment of hepatic lipidosis: Dilute 10% NAC with saline 1:4 and administer IV using a 0.25 micron filter.
- Mucolytic: Dilute with saline for nebulization.
- Paracetamol poisoning: IV administration is strongly preferred in cats as bioavailability is reduced with oral administration.
- KCS: Rarely used now for this indication.
馬
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| To help break up chondroids in the guttural pouch | Instill 20% solution | Local instillation | — | — | 🌎 NA |
| Meconium impaction in neonatal foals | 8 grams in 20 g sodium bicarbonate in 200 mL water (pH of 7.6), give as enema as needed to effect | Enema | PRN | — | 🌎 NA |
| Meconium impaction in neonatal foals | Infuse slowly 100-200 mL of 4% acetylcysteine solution and retain for 30-45 minutes | Retention enema | Once | Retain 30-45 minutes | 🌎 NA |
- Meconium impaction in neonatal foals: Use a 30 French Foley catheter with a 30 cc bulb. Monitor for possible bladder distention.
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
乙醯半胱胺酸（常被稱為 NAC）在獸醫學中是一種用途廣泛的治療藥物。它最主要被用作普拿疼（對乙醯氨基酚）中毒的救命解毒劑，特別是在貓和狗身上，能預防嚴重的肝臟壞死和變性血紅素血症。
除了作為解毒劑外，乙醯半胱胺酸也是一種強效的祛痰劑（黏液溶解劑）。當投予至呼吸道時，它能有效分解濃稠的黏液，幫助清除呼吸道分泌物。
臨床應用：
- 毒物學： 治療對乙醯氨基酚、木糖醇和苯酚中毒的主要藥物。
- 呼吸系統： 透過霧化或氣管內滴注，治療慢性上呼吸道疾病或黏液過多的情況。
- 眼科： 局部應用於抑制膠原蛋白酶，阻止「融化性」角膜潰瘍的惡化。
- 馬科醫學： 局部使用以溶解喉囊內的軟骨樣凝塊，並作為灌腸劑治療新生小馬頑固性胎便阻塞。
- 內科： 作為貓脂肪肝的輔助治療，以及犬退化性脊髓病的軼事性療法。
作用機轉
Antidote Mechanism (Hepatoprotection): Acetaminophen is metabolized in the liver to a highly reactive and toxic intermediate called NAPQI (N-acetyl-p-benzoquinone imine). Normally, NAPQI is safely conjugated by endogenous glutathione. In an overdose, glutathione is rapidly depleted, allowing NAPQI to cause severe oxidative stress and hepatocellular necrosis. Acetylcysteine acts as a glutathione precursor and provides an alternate sulfhydryl substrate to conjugate directly with NAPQI, thereby neutralizing the toxin and restoring cellular antioxidant defenses.
Mucolytic Mechanism: The free sulfhydryl group (-SH) on the acetylcysteine molecule directly interacts with mucoproteins in respiratory secretions. It cleaves the disulfide bonds linking these proteins, which drastically reduces the viscosity of both purulent and non-purulent mucus. This effect is optimal in an alkaline environment (pH 7-9). It has no effect on living tissue or fibrin.
安全性與警告
禁忌症
- Hypersensitivity to the drug (specifically for pulmonary indications)
不良反應
- Nausea and vomiting (especially with oral administration due to poor palatability)
- Urticaria (rare)
- Bronchospasm, chest tightness, and bronchial/tracheal irritation (when inhaled)
- Blood pressure changes and allergic reactions (reported with IV boluses in humans)
注意事項
Use with caution in animals with pre-existing bronchospastic diseases (e.g., feline asthma) when administering via the pulmonary route, as it may trigger bronchospasm. Oral administration can be challenging due to the extremely foul taste and odor (sulfur/rotten eggs); administration via a gastric or duodenal tube is often necessary. If using the inhalation solution for intravenous administration, it is highly recommended to use a 0.2-micron in-line filter. Use caution in nursing dams as it is unknown if the drug enters milk.
藥物交互作用
May adsorb orally administered acetylcysteine, potentially reducing its systemic absorption and efficacy. A 2-3 hour wait between charcoal and oral acetylcysteine is recommended, or acetylcysteine should be given intravenously.
監測
- Hepatic enzymes (especially in dogs)
- Acetaminophen levels (if available)
- Hemogram, specifically monitoring methemoglobin values (especially critical in cats)
- Serum electrolytes
- Hydration status
藥物動力學
吸收
Well absorbed from the gastrointestinal tract when administered orally.
分佈
When administered via nebulization or intratracheally, most of the drug remains localized in the pulmonary tract to participate in sulfhydryl-disulfide reactions; the remainder is systemically absorbed.
代謝
Absorbed drug is rapidly deacetylated into the amino acid cysteine in the liver, which is then further metabolized.
過量
Acetylcysteine is considered quite safe in overdose situations. The LD50 in dogs is reported to be 1 g/kg orally and 700 mg/kg intravenously. Massive overdoses may result in gastrointestinal distress (nausea, vomiting) or hypersensitivity reactions, but life-threatening toxicity from the drug itself is rare.
可用產品
劑型
- Injection: 20% (200 mg/mL)
- Oral/Inhalation Solution: 10% and 20%
- Oral capsules: 600 mg (OTC nutritional supplement)
人用標示
- Acetylcysteine injection: 20% (200 mg/mL) in 30 mL single-dose vials (Acetadote)
- Acetylcysteine Oral Solution: 10% & 20% (Mucomyst)
- Acetylcysteine Inhalation Solution: 10% & 20% (Mucomyst)
- N-Acetylcysteine (NAC) 600 mg capsules (OTC nutritional supplement)
各地核准狀態
Human authorized products used under the cascade.
Human authorized products used under the cascade.
暫無法規資料: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
儲存與穩定性
Unopened vials should be stored at room temperature (15-30°C). Once opened, vials must be refrigerated and used within 96 hours (products labeled specifically for IV use should be used within 24 hours). Acetylcysteine is incompatible with oxidizing agents and can liberate hydrogen sulfide when exposed to rubber, copper, or iron. It is incompatible in solution with amphotericin B, ampicillin, erythromycin, tetracyclines, hydrogen peroxide, and trypsin.
飼主須知
僅限緊急使用： 乙醯半胱胺酸通常在臨床監督的緊急情況下使用，用於治療危及生命的毒物攝入（如普拿疼/對乙醯氨基酚中毒）。
- 味道與氣味： 口服液體製劑具有非常強烈、難聞的氣味（類似臭雞蛋或硫磺味），且味道極差。您的寵物很可能會抗拒服用。在醫院中，通常會透過餵食管給藥，或與強烈調味劑混合，以確保寵物攝入完整劑量。
- 副作用： 最常見的副作用是噁心或嘔吐。如果您的寵物在口服後不久嘔吐，請立即聯繫您的獸醫師，因為可能需要重新給藥。
- 監測： 您的寵物將需要密切的醫療監測，包括頻繁的血液檢查，以確保肝臟正在恢復且毒素正從體內清除。
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