響尾蛇抗毒血清 / 多價蝮蛇抗毒血清
多價蝮蛇抗毒血清是一種關鍵且能挽救生命的**解毒劑**，用於治療北美、中美及南美洲蝮蛇（如響尾蛇、銅頭蛇、棉口蛇、三色矛頭蝮）的毒液咬傷。 * **劑型**：提供**馬來源**產品（完整IgG抗體）及**羊來源**產品（Fab片段，例如CroFab®）。 * **風險**：獸醫標籤的馬來源產品中高達50%含有馬白蛋白及其他蛋白質，具有顯著的過敏反應（過敏性休克）風險。 * **臨床要點**：雖然羊來源Fab產品（CroFab）為人類標籤，但在獸醫學中常被標示外使用。與完整IgG馬來源產品相比，Fab片段引發過敏性休克的風險通常較低，但其半衰期較短，可能需要重複給藥以防止毒性復發。 * 治療需要積極的支持性護理，且費用通常非常高昂。
作用機制: Antivenins provide **passive immunity** to the patient. * They contain concentrated serum globulins (or Fab fragments) obtained from animals (horses or sheep) hyperimmunized with pit viper venom. * **Mechanism**: The immunoglobulins directly bind to and neutralize the complex toxic proteins and enzymes present in the venom. * **Effect** → Rapidly reverses venom-related systemic signs and coagulation abnormalities. * *Note*: Venom-induced thrombocytopenia, particularly from Timber Rattlesnakes, may be resistant to antivenin treatment.
各物種劑量
- Pit viper envenomation · 1-2 vials of antivenin. Initially, give one vial, by diluting to 100-250 mL of crystalloid fluids and initially administer by slow IV · IV · prn · Adjust infusion volume in smaller patients to prevent fluid overload.
- Systemic effects of envenomation · 1-2 vials slowly IV diluted in 250-500 mL saline or lactated Ringer's · IV · prn · Use only if necessary to treat systemic effects. Administer antihistamines; corticosteroids are contraindicated.
- Pit viper envenomation · 1-2 vials of antivenin. Initially, give one vial, by diluting to 100-250 mL of crystalloid fluids and initially administer by slow IV · IV · prn · Adjust infusion volume in smaller patients to prevent fluid overload. Intravascular bites or bites to torso/tongue require prompt, aggressive administration.
- Pit viper envenomation · 1-5 rehydrated vials (10-50 mL) IV depending on severity of symptoms, duration of time after the bite, snake size, patient size. Additional doses may be given every 2 hours as required. If unable to give IV, may administer IM as close to bite as practical. · IV/IM · q2h as required · The smaller the victim, the larger the dose (venom amount/kg is higher).
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。
給藥途徑
禁忌症
- Known severe hypersensitivity to equine or ovine proteins (relative contraindication in life-threatening envenomation)
不良反應
- Anaphylaxis (Type I hypersensitivity)
- Anaphylactoid reactions
- Serum sickness (Type III hypersensitivity, delayed)
- Nausea
- Pruritus
- Hyperemia of the inner pinna
藥物相互作用
- Analgesics/Sedatives · May mask the clinical signs associated with the venom; use with caution initially.
- Antihistamines · Theoretical risk of potentiating venom, though diphenhydramine is routinely and safely used by clinicians for pre-treatment.
- Beta-blockers · May mask the early signs associated with anaphylaxis.
- Corticosteroids · Generally out of favor for treating snakebite envenomation, but may be useful to treat secondary anaphylaxis. Contraindicated in horses per some references.
- Heparin · Reportedly not effective in treating the thrombin-like enzymes found in rattlesnake venom.
監測
- Signs associated with an allergic response (anaphylaxis, anaphylactoid-reactions, serum sickness)
- CBC with platelets
- Coagulation parameters
- Biochemical profile
- Hydration status
- ECG
過量
Specific overdose information is not provided, but fluid overload is a significant risk in smaller patients receiving large volumes of crystalloid fluids used to dilute the antivenin.
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。