氯解磷定 (Pralidoxime Chloride)
Pralidoxime Chloride
2-Formyl-1-methylpyridinium chloride oxime
別名: Protopam Chloride · 2-Formyl-1-methylpyridinium chloride oxime · 2-PAM chloride · 2-PAMCl · 2-pyridine aldoxime methochloride
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 |
|---|---|---|---|---|---|
| Organophosphate poisoning | 20 mg/kg | IM or slow IV | 2-3 times a day | — | 🌎 NA |
| Organophosphate poisoning | 10-15 mg/kg | IM or SC | q8-12h | 36 hour minimum | 🌎 NA |
| Organophosphate poisoning | 50 mg/kg | slow IV | May repeat in one hour if severe | Recovery should occur gradually over 48 hours | 🌎 NA |
| Organophosphate poisoning | 50 mg/kg | IV | Repeat in one hour if signs persist, then q8h | 24-48 hours | 🌎 NA |
- Organophosphate poisoning: Works best when combined with atropine. Initial dose IM or slow IV; subsequent doses IM or SC.
- Organophosphate poisoning: Give atropine first (0.1 mg/kg IV, then 0.3 mg/kg IM). Dilute pralidoxime in 10% glucose. For small dogs, may administer IM or IP. Reduce dose in renal failure.
- Organophosphate poisoning: Give slowly or with fluids over a 30-minute period. If clinical signs intensify (e.g., respiratory depression), reduce dose and give as repeated one-hour infusions every 4-8 hours in combination with atropine.
貓
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Organophosphate poisoning | 20 mg/kg | IM or slow IV | 2-3 times a day | — | 🌎 NA |
| Organophosphate poisoning | 10-15 mg/kg | IM or SC | q8-12h | 36 hour minimum | 🌎 NA |
| Organophosphate poisoning | 50 mg/kg | slow IV | May repeat in one hour if severe | Recovery should occur gradually over 48 hours | 🌎 NA |
| Organophosphate poisoning | 20 mg/kg | IV | Repeat in one hour if signs persist, then q8h | 24-48 hours | 🌎 NA |
| Organophosphate poisoning | 20 mg/kg | IM or IV | May repeat q6-8h | — | 🌎 NA |
- Organophosphate poisoning: Works best when combined with atropine. Initial dose IM or slow IV; subsequent doses IM or SC.
- Organophosphate poisoning: Give atropine first. Dilute in 10% glucose. May administer IM or IP. Reduce dose in renal failure.
- Organophosphate poisoning: Give slowly or with fluids over a 30-minute period.
- Organophosphate poisoning: Give within first 24 hours of exposure. Combine with atropine or give separately. Do not use in carbamate toxicity.
鳥
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Organophosphate poisoning | 10-20 mg/kg | Not specified | q8-12h | — | 🌎 NA |
| Organophosphate poisoning | 10-100 mg/kg | IM | q24-48h or repeat once in 6 hours | — | 🌎 NA |
- Organophosphate poisoning: Give with atropine (0.2-0.5 mg/kg IM q3-4h).
馬
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Organophosphate poisoning | 20 mg/kg (may require up to 35 mg/kg) | IV | q4-6h | — | 🌎 NA |
牛
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Organophosphate poisoning | 30 mg/kg | IM | q8h | — | 🌎 NA |
| Organophosphate poisoning | 25-50 mg/kg | IV | Single dose, or maximum of 100 mg/kg/day as an IV drip | — | 🌎 NA |
- Organophosphate poisoning: FARAD recommends a 28-day meat and a 6-day milk withdrawal time.
- Organophosphate poisoning: Give as a 20% solution over 6 minutes.
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
氯解磷定（通常稱為 2-PAM）是一種特異性解毒劑，在獸醫學中主要用於治療有機磷 (OP) 中毒。有機磷常見於早期的殺蟲劑、農用化學品及某些神經毒劑中。它們會不可逆地結合並抑制乙醯膽鹼酯酶 (AChE)，導致神經突觸和神經肌肉接合處的乙醯膽鹼大量累積。
氯解磷定作為一種膽鹼酯酶復活劑，能在有機磷與酵素的結合變成永久性（此過程稱為「老化」）之前，有效地將有機磷分子從酵素上剝離。
臨床要點： 氯解磷定幾乎總是與阿托品 (Atropine) 併用。阿托品能阻斷乙醯膽鹼過多引起的毒蕈鹼樣作用（SLUDDE 症狀：流涎、流淚、排尿、排便、呼吸困難、嘔吐），而氯解磷定則是緩解菸鹼樣作用（特別是嚴重的肌肉震顫、無力和包括呼吸肌在內的癱瘓）所必需的。它通常不建議用於氨基甲酸酯 (Carbamate) 中毒，因為氨基甲酸酯與 AChE 的結合會自發性逆轉，不需要使用肟類復活劑。
作用機轉
Pralidoxime works by directly reactivating the acetylcholinesterase enzyme that has been inhibited by organophosphates.
- Organophosphates bind to the esteratic site of acetylcholinesterase (AChE) via phosphorylation, inactivating the enzyme.
- Accumulation of acetylcholine (ACh) occurs at muscarinic and nicotinic receptors → severe overstimulation.
- Pralidoxime possesses a high affinity for the AChE enzyme.
- Via nucleophilic attack, the oxime group of pralidoxime binds to the offending phosphoryl group of the organophosphate.
- The pralidoxime-organophosphate complex breaks away from the enzyme → AChE is reactivated and resumes breaking down ACh.
Important Mechanistic Note: If the phosphorylated enzyme undergoes a chemical change (loss of an alkyl group) before pralidoxime is administered, the bond becomes permanent. This is known as "aging". Therefore, pralidoxime is most effective when given within 24 hours of exposure, though some benefit may be seen up to 36-48 hours in massive exposures.
安全性與警告
禁忌症
- Hypersensitivity to pralidoxime
- Carbamate poisoning (generally not recommended as inhibition is rapidly reversible)
不良反應
- Tachycardia (especially with rapid IV injection)
- Muscle rigidity
- Transient neuromuscular blockade
- Laryngospasm
注意事項
Use with caution in patients receiving anticholinesterase agents for the treatment of myasthenia gravis, as it may precipitate a myasthenic crisis. Use cautiously and at a reduced dosage rate in patients with renal impairment. Must generally be given within 24 hours of exposure to be effective. Rapid IV injection should be avoided to prevent tachycardia, muscle rigidity, and laryngospasm.
藥物交互作用
Anticholinesterases can potentiate the action of barbiturates; use with caution.
Use should be avoided in patients with organophosphate toxicity.
Use should be avoided in patients with organophosphate toxicity.
Use should be avoided in patients with organophosphate toxicity.
Use should be avoided in patients with organophosphate toxicity.
Use should be avoided in patients with organophosphate toxicity.
監測
- Clinical signs associated with organophosphate poisoning (SLUDDE signs, muscle fasciculations, weakness)
- Heart rate and rhythm (especially during IV administration)
- Respiratory rate and effort
藥物動力學
吸收
Marginally absorbed after oral dosing; oral dosage forms are no longer available in the United States.
分佈
Distributed primarily throughout the extracellular water. Because of its quaternary ammonium structure, it is historically not believed to enter the CNS in significant quantities, but recent studies and clinical responses have led some to question this belief.
代謝
Thought to be metabolized by the liver.
排除
Excreted as both metabolite(s) and unchanged drug in the urine.
過量
The acute LD50 of pralidoxime in dogs is 190 mg/kg. At high dosages, it causes signs associated with its own anticholinesterase activity.
Clinical signs of toxicity in dogs may be exhibited as:
- Muscle weakness
- Ataxia
- Vomiting
- Hyperventilation
- Seizures
- Respiratory arrest
- Death
可用產品
劑型
- Powder for injection
人用標示
- Pralidoxime Chloride Powder for Injection: 1 gram in 20 mL single-use vials (Protopam Chloride)
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
Unless otherwise instructed by the manufacturer, pralidoxime chloride powder for injection should be stored at room temperature. After reconstituting with sterile water for injection, the solution should be used within a few hours. Do not use sterile water with preservatives added.
飼主須知
- 緊急治療： 本藥物是針對特定類型農藥或神經毒劑（有機磷）中毒的關鍵救命解毒劑。
- 需要住院： 您的寵物在接受此藥物治療期間，需要住院並由獸醫專業人員密切監測。
- 具時效性： 此解毒劑在接觸毒物後越早給予效果越好（理想情況下在最初 24 小時內）。
- 合併治療： 它幾乎總是與另一種稱為阿托品 (Atropine) 的解毒劑一起給予，以全面控制嚴重的中毒症狀。
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