解磷定 / 普拉肟
解磷定（通常稱為2-PAM）是獸醫學中用於治療**有機磷（OP）**中毒的特效解毒劑。它用於逆轉與有機磷中毒相關的神經肌肉麻痺。 > **警告：** 解磷定通常禁忌用於氨基甲酸酯（Carbamate）中毒，因為它可能會使臨床症狀惡化或無效。 **臨床提示：** 解磷定不易穿過血腦屏障；因此，它主要緩解周邊菸鹼受體症狀（肌肉震顫、無力、麻痺），但不能緩解中樞神經系統症狀。它必須始終與**阿托品（Atropine）**結合使用，阿托品可解決危及生命的毒蕈鹼受體症狀（心動過緩、支氣管收縮和SLUDGE症狀：流涎、流淚、排尿、排便、腸胃不適、嘔吐）。為了有效，解磷定必須在有機磷-酵素複合物發生「老化」（永久不可逆結合）之前儘早給藥，這通常發生在暴露後24-48小時內。
作用機制: Pralidoxime works by reactivating the **acetylcholinesterase (AChE)** enzyme that has been inactivated by organophosphate binding. It binds to the OP-AChE complex → cleaves the phosphate bond → releases the OP → restores the enzyme's ability to break down **acetylcholine** at the synaptic cleft. Additionally, it directly detoxifies certain unbound OP molecules through chemical inactivation and retards the 'aging' of phosphorylated cholinesterase into a non-reactive, permanently damaged form.
各物種劑量
- Organophosphate toxicity · 10-20 mg/kg · IV/IM/SC · bid to tid · Until nicotinic signs resolve (usually 1-2 days) · Administer IV very slowly over 15-30 minutes. Can also be given as a continuous rate infusion (CRI). Must be given in conjunction with atropine.
- Organophosphate toxicity · 10-20 mg/kg · IV/IM/SC · bid to tid · Until nicotinic signs resolve (usually 1-2 days) · Administer IV very slowly over 15-30 minutes. Must be given in conjunction with atropine.
劑量為合格獸醫專業人員的臨床參考。請務必對照最新藥品仿單及個別病患確認。
給藥途徑
禁忌症
- Carbamate toxicity (can exacerbate toxicity)
- Poisoning by non-anticholinesterase compounds
- Hypersensitivity to pralidoxime
不良反應
- Tachycardia
- Muscle rigidity
- Transient neuromuscular blockade (if given too rapidly IV)
- Hypertension
- Hyperventilation
藥物相互作用
- Phenothiazines · May exacerbate organophosphate toxicity · major
- Succinylcholine · Prolonged neuromuscular blockade due to cholinesterase inhibition · major
- Morphine · May exacerbate respiratory depression in OP toxicity · moderate
- Aminophylline · May exacerbate toxicity · moderate
監測
- Heart rate and rhythm (ECG)
- Respiratory rate and effort
- Resolution of muscle fasciculations and weakness
- Blood pressure
- Renal function (urine output)
過量
Overdose can cause paradoxical neuromuscular blockade, muscle rigidity, tachycardia, and worsening of cholinergic signs. Treatment is supportive, including artificial ventilation if respiratory paralysis occurs.
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。