Essential cofactor for hepatic carboxylation of coagulation factors II, VII, IX, and X; directly reverses vitamin K antagonist (anticoagulant rodenticide) poisoning
At a glance
Class
Fat-soluble vitamin / Coagulation factor cofactor
Storage
Store below 25°C, protect from light; give PO with fatty food to enhance absorption
Dosing
Anticoagulant rodenticide toxicosis
Frequency
BID (initially); then SID once stable
Max dose
250 mg/dose; 500 mg/day
Duration: First-gen warfarin: 7 days; Second-gen (brodifacoum): 4–6 weeks; recheck PT 48–72h after stopping
Anticoagulant rodenticide toxicosis
Frequency
BID initially; then SID
Max dose
50 mg/dose; 100 mg/day
Duration: Same as dog; duration depends on rodenticide generation
Safety
Absolute contraindications — do not use
Adverse effects
Common
Pain at SC/IM injection site
Serious
Anaphylactoid reaction (IV use)
Hematoma at injection site
PT/PTT (baseline, 48h after starting, 48–72h after stopping)Signs of bleeding
Interactions
No documented interactions.
Brands
India
Phytomenadione IP
Neon Labs
FAQs
Frequently asked questions
›What is Vitamin K1 (Phytonadione)?
Vitamin K1 (Phytonadione) is a fat-soluble vitamin / coagulation factor cofactor used in pets. Essential cofactor for hepatic carboxylation of coagulation factors II, VII, IX, and X; directly reverses vitamin K antagonist (anticoagulant rodenticide) poisoning
›What is Vitamin K1 (Phytonadione) used for in pets?
Vitamin K1 (Phytonadione) is used in veterinary medicine for: Anticoagulant rodenticide toxicosis.
›What is the Vitamin K1 (Phytonadione) dose for dogs?
For dogs, Vitamin K1 (Phytonadione) is typically dosed as follows — Anticoagulant rodenticide toxicosis: 2.5–5 mg/kg PO/SC/IM BID (initially); then SID once stable. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What is the Vitamin K1 (Phytonadione) dose for cats?
For cats, Vitamin K1 (Phytonadione) is typically dosed as follows — Anticoagulant rodenticide toxicosis: 2.5–5 mg/kg PO/SC/IM BID initially; then SID. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What are the side effects of Vitamin K1 (Phytonadione)?
Common: Pain at SC/IM injection site. Serious (call your vet immediately): Anaphylactoid reaction (IV use), Hematoma at injection site.
›Does Vitamin K1 (Phytonadione) need a prescription?
Yes. Vitamin K1 (Phytonadione) is a prescription medication and should only be administered under veterinary supervision.
›When should Vitamin K1 (Phytonadione) not be used?
Do not use Vitamin K1 (Phytonadione) if: IV injection (anaphylaxis risk).
References
CDSCO approvals (India) — 1
Injection of Vitamin A, D, B
M/s Roche Products Bombay · Approved 1970 April
Vitamin Preparation.
Source: CDSCO Veterinary Drug Approval Registry (1969–2026)
References
Textbooks & handbooks
- Plumb, D.C. Plumb's Veterinary Drug Handbook. 10th ed., Wiley-Blackwell, 2023.
- Vail, D.M., Thamm, D.H., & Liptak, J.M. (eds.). Withrow & MacEwen's Small Animal Clinical Oncology. 6th ed., Saunders/Elsevier, 2020.
- Riviere, J.E., & Papich, M.G. (eds.). Veterinary Pharmacology and Therapeutics. 10th ed., Wiley-Blackwell, 2018.
- National Research Council. Nutrient Requirements of Dogs and Cats. National Academies Press, Washington DC, 2006.
- The Merck Veterinary Manual. Merck & Co., Online edition. https://www.merckvetmanual.com/
Clinical guidelines & consensus
- Fletcher, D.J., Boller, M., Brainard, B.M., et al. "RECOVER Evidence and Knowledge Gap Analysis on Veterinary CPR." Journal of Veterinary Emergency and Critical Care, 2012;22(S1):S102–S131.
- American Animal Hospital Association. 2018 AAHA Diabetes Management Guidelines for Dogs and Cats. AAHA Press.
Journals & peer-reviewed studies
- Hogan, D.F., Fox, P.R., Jacob, K., et al. "Secondary prevention of cardiogenic arterial thromboembolism in the cat: The FAT CAT study." Journal of Veterinary Cardiology, 2015;17(Suppl 1):S306–S317.
- Boswood, A., Häggström, J., Gordon, S.G., et al. "Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly: The EPIC Study — A Randomized Clinical Trial." Journal of Veterinary Internal Medicine, 2016;30(6):1765–1779.
- ASPCA Animal Poison Control Center. Toxicology and Poison Management Guidelines. American Society for the Prevention of Cruelty to Animals. https://www.aspca.org/pet-care/animal-poison-control
Regulatory & approvals
- Central Drugs Standard Control Organisation (CDSCO), Government of India. Veterinary Drug Approval Registry, 1969–2026. Directorate General of Health Services. https://cdsco.gov.in/
Databases
- Washington State University, College of Veterinary Medicine. Veterinary Clinical Pharmacology Laboratory (VCPL) — MDR1 Multidrug Sensitivity Database. https://vcpl.vetmed.wsu.edu/
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet.
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