Phytonadione (Vitamin K1)
別名: Mephyton, K-Caps, Veda-K1, Veta-K1, K-Chews, K-Ject, Vita-Jec, Aqua-Mephyton, Konakion, Vitamine K1 Laboratoire TVM, Vitamin K1, K-1
* **Strict Adherence to Schedule:** Because modern rat poisons (second-generation rodenticides) stay in the body for a very long time, it is critical to give this medication for the **entire duration** prescribed (often 3-4 weeks). Stopping early can result in sudden, life-threatening internal bleeding. * **Give with Food:** Administer oral Vitamin K1 with a **fatty meal** (like canned pet food, a small amount of cheese, or peanut butter) to significantly boost how much drug is absorbed into the bloodstream. * **Exercise Restriction:** Keep your pet quiet and strictly confined (leash walks only, no jumping or rough play) during therapy to minimize the risk of bruising or internal bleeding from minor bumps. * **Follow-up Testing:** Your veterinarian will likely need to recheck your pet's blood clotting times about 48 hours *after* the last dose of Vitamin K1 to ensure the poison is completely out of their system.
劑量必須由獸醫按你寵物的個別情況決定。切勿在沒有獸醫指導下給予人類藥物或其他寵物的處方藥。
用途
- Adjunctive therapy of acute liver failure
- Anticoagulant rodenticide toxicity (exposed but non-bleeding)
- Anticoagulant rodenticide toxicity (bleeding patient)
- Anticoagulant rodenticide toxicity (symptomatic)
- Known 1st generation coumarin toxicity or vitamin K1 deficiency
- Known 2nd generation coumarin (brodifacoum) toxicity
- Known inandione (diphacinone) or unknown anticoagulant toxicity
- Liver disease (pre-biopsy)
- Warfarin (or related compounds) toxicity
- Warfarin (or related compounds) toxicity
- Warfarin (or related compounds) toxicity
- Warfarin (or related compounds) toxicity
給藥方式
可能的副作用
- Anaphylactoid reactions (especially following IV administration)
- Acute bleeding from the injection site (IM administration during early stages of treatment)
- Slow or poor absorption from SC or PO routes in hypovolemic patients
- Anaphylactic reactions (following IV administration)
- Haemolytic anaemia (in cats when overdosed)
- Anaphylaxis (primarily with IV administration)
- Injection site reactions (pain, swelling)
- Hematoma formation at injection sites (due to underlying coagulopathy)
注意事項與禁忌
- Known hypersensitivity to phytonadione or its components
- Hypoprothrombinemia due to hepatocellular damage (Vitamin K cannot correct this if the liver cannot synthesize the protein precursors)
- Intravenous administration (relative contraindication due to anaphylaxis risk)
- Known hypersensitivity to phytomenadione
- Intramuscular administration in severely coagulopathic patients (risk of severe hematoma)
- **Intravenous Administration Warning:** The FDA-CVM warns against administering phytonadione IV due to a significant risk of severe anaphylactoid reactions. If IV use is absolutely necessary (e.g., severe bleeding with very high INR in large animals), it must be diluted and given extremely slowly. **Injection Site Bleeding:** IM injections can cause acute bleeding at the site in coagulopathic patients. Use small-gauge needles for SC or IM injections. **Delayed Onset:** It takes 6-12 hours for new clotting factors to be synthesized. Emergency needs for clotting factors in actively bleeding patients MUST be met with blood products (fresh frozen plasma or whole blood). **Absorption:** SC or PO doses may be poorly absorbed in hypovolemic animals. Oral absorption requires bile salts and is significantly enhanced (4-5x) by administering with a fatty meal.
藥物相互作用
- Oral Antibiotics: May decrease the numbers of Vitamin K-producing bacteria in the gut, though chronic therapy usually has no significant effect on phytonadione absorption.
- Mineral Oil: Concomitant oral administration may reduce the GI absorption of oral Vitamin K.
- Warfarin (and other coumarin/indanedione anticoagulants): Phytonadione directly antagonizes the anticoagulant effects of these drugs.
- Phenylbutazone, Aspirin, Chloramphenicol, Sulfonamides, Diazoxide, Allopurinol, Cimetidine, Metronidazole, Anabolic Steroids, Erythromycin, Ketoconazole, Propranolol, Thyroid Drugs: May prolong or enhance the effects of anticoagulants, thereby antagonizing some of the therapeutic effects of phytonadione.
- Aspirin: Antagonizes the effects of vitamin K
- Chloramphenicol: Antagonizes the effects of vitamin K
- Allopurinol: Antagonizes the effects of vitamin K
- Diazoxide: Antagonizes the effects of vitamin K
- Cimetidine: Antagonizes the effects of vitamin K
- Metronidazole: Antagonizes the effects of vitamin K
常見問題
Phytonadione (Vitamin K1)用於寵物有甚麼用途？
* **Strict Adherence to Schedule:** Because modern rat poisons (second-generation rodenticides) stay in the body for a very long time, it is critical to give this medication for the **entire duration** prescribed (often 3-4 weeks). Stopping early can result in sudden, life-threatening internal bleeding. * **Give with Food:** Administer oral Vitamin K1 with a **fatty meal** (like canned pet food, a small amount of cheese, or peanut butter) to significantly boost how much drug is absorbed into the bloodstream. * **Exercise Restriction:** Keep your pet quiet and strictly confined (leash walks only, no jumping or rough play) during therapy to minimize the risk of bruising or internal bleeding from minor bumps. * **Follow-up Testing:** Your veterinarian will likely need to recheck your pet's blood clotting times about 48 hours *after* the last dose of Vitamin K1 to ensure the poison is completely out of their system.
Phytonadione (Vitamin K1)對我的寵物安全嗎？
劑量必須由獸醫按你寵物的個別情況決定。切勿在沒有獸醫指導下給予人類藥物或其他寵物的處方藥。
本文僅供一般健康教育，不能取代專業獸醫意見。如寵物身體不適，請諮詢獸醫。