Fitonadiona (Vitamina K1)
Phytonadione (Vitamin K1)
Phylloquinone (2-methyl-3-phytyl-1,4-naphthoquinone)
También conocido como: K-Caps · Veda-K1 · Veta-K1 · K-Chews · K-Ject · Vita-Jec · Aqua-Mephyton · Konakion · Vitamine K1 Laboratoire TVM · Vitamin K1 · K-1 · methylphytylnaphthochinonum · phylloquinone · phytomenadionum · phytomenadione · Phytonadione · Methylphytylnaphthoquinone
Revisado por el equipo veterinario de VetSheetActualizado 5 abr 2026Referencia veterinaria basada en la evidencia
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Dosis por especie
🌎 NA — North America🌍 EU — Europe
Perros
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Adjunctive therapy of acute liver failure | 1-5 mg/kg PO or SC q24h | PO, SC | q24h | — | 🌎 NA |
| Anticoagulant rodenticide toxicity (exposed but non-bleeding) | 1.25-2.5 mg/kg PO twice daily with a fatty meal | PO | q12h | 2-4 weeks | 🌎 NA |
| Anticoagulant rodenticide toxicity (bleeding patient) | 2.5 mg/kg PO twice daily with a fatty meal | PO | q12h | minimum of 4 weeks | 🌎 NA |
| Anticoagulant rodenticide toxicity (symptomatic) | Loading dose of 2.5-5 mg/kg PO, then 3-5 mg/kg PO divided twice daily | PO | q12h | 14 days (1st gen) or at least 30 days (2nd gen/unknown) | 🌎 NA |
| Known 1st generation coumarin toxicity or vitamin K1 deficiency | initially 2.5 mg/kg s.c. in several sites, then 1-2.5 mg/kg in divided doses p.o. | SC/PO | q8-12h | 5-7 days | 🌍 EU |
| Known 2nd generation coumarin (brodifacoum) toxicity | initially 5 mg/kg s.c. in several sites, then 2.5 mg/kg p.o. | SC/PO | q12h | 3 weeks | 🌍 EU |
| Known inandione (diphacinone) or unknown anticoagulant toxicity | initially 2.5-5 mg/kg s.c. over several sites. Then 2.5 mg/kg p.o. divided | SC/PO | q8-12h | 3-4 weeks | 🌍 EU |
| Liver disease (pre-biopsy) | 0.5-1.0 mg/kg | SC | q12h | 1-2 days | 🌍 EU |
- Anticoagulant rodenticide toxicity (exposed but non-bleeding): Only give SC with starting dose if patient is vomiting or activated charcoal was administered.
- Anticoagulant rodenticide toxicity (bleeding patient): Plasma/blood transfusions are a necessity. Re-examine clotting times 2-3 days following cessation of therapy.
- Anticoagulant rodenticide toxicity (symptomatic): Check PT or PIVKA 48 hours after stopping therapy; if prolonged, continue for another week.
- Known 1st generation coumarin toxicity or vitamin K1 deficiency: Administer SC initially, followed by oral maintenance.
- Known 2nd generation coumarin (brodifacoum) toxicity: Restrict activity for 1 week post-treatment. Re-evaluate coagulation status 3 weeks after cessation of treatment.
- Known inandione (diphacinone) or unknown anticoagulant toxicity: Re-evaluate coagulation status 2 days after stopping therapy. If PT is elevated, continue therapy for 2 additional weeks. If normal, rest for 1 week.
- Liver disease (pre-biopsy): Re-evaluate coagulation time before biopsy. If minimal improvement, fresh frozen plasma may be required.
Gatos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Adjunctive therapy of acute liver failure | 1-5 mg/kg PO or SC q24h | PO, SC | q24h | — | 🌎 NA |
| Anticoagulant rodenticide toxicity (exposed but non-bleeding) | 1.25-2.5 mg/kg PO twice daily with a fatty meal | PO | q12h | 2-4 weeks | 🌎 NA |
| Anticoagulant rodenticide toxicity (bleeding patient) | 2.5 mg/kg PO twice daily with a fatty meal | PO | q12h | minimum of 4 weeks | 🌎 NA |
| Anticoagulant rodenticide toxicity (symptomatic) | Loading dose of 2.5-5 mg/kg PO, then 3-5 mg/kg PO divided twice daily | PO | q12h | 14 days (1st gen) or at least 30 days (2nd gen/unknown) | 🌎 NA |
| Known 1st generation coumarin toxicity or vitamin K1 deficiency | initially 2.5 mg/kg s.c. in several sites, then 1-2.5 mg/kg in divided doses p.o. | SC/PO | q8-12h | 5-7 days | 🌍 EU |
| Known 2nd generation coumarin (brodifacoum) toxicity | initially 5 mg/kg s.c. in several sites, then 2.5 mg/kg p.o. | SC/PO | q12h | 3 weeks | 🌍 EU |
| Known inandione (diphacinone) or unknown anticoagulant toxicity | initially 2.5-5 mg/kg s.c. over several sites. Then 2.5 mg/kg p.o. divided | SC/PO | q8-12h | 3-4 weeks | 🌍 EU |
| Liver disease (pre-biopsy) | 0.5-1.0 mg/kg | SC | q12h | 1-2 days | 🌍 EU |
- Known 1st generation coumarin toxicity or vitamin K1 deficiency: Administer SC initially, followed by oral maintenance.
- Known 2nd generation coumarin (brodifacoum) toxicity: Restrict activity for 1 week post-treatment. Re-evaluate coagulation status 3 weeks after cessation of treatment.
- Known inandione (diphacinone) or unknown anticoagulant toxicity: Re-evaluate coagulation status 2 days after stopping therapy. If PT is elevated, continue therapy for 2 additional weeks. If normal, rest for 1 week.
- Liver disease (pre-biopsy): Re-evaluate coagulation time before biopsy. If minimal improvement, fresh frozen plasma may be required.
Pequeños mamíferos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Anticoagulant rodenticide toxicity | 5 mg/kg/day divided q8-12h | PO | q8-12h | — | 🌎 NA |
| Anticoagulant rodenticide toxicity (symptomatic) | Loading dose of 2.5-5 mg/kg PO, then 3-5 mg/kg PO divided twice daily | PO | q12h | 14-30 days | 🌎 NA |
- Anticoagulant rodenticide toxicity: Give with a fatty meal (e.g., peanut butter). Do not give IV; SC can cause anaphylaxis.
- Anticoagulant rodenticide toxicity (symptomatic): Treat pocket pets at the high end of this dosage range.
Aves
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Hemorrhagic disorders | 0.25-0.5 mL/kg IM of the 10 mg/mL injectable product | IM | — | — | 🌎 NA |
| Hemorrhagic disorders | 0.2-2.5 mg/kg IM as needed | IM | as needed | usually only 1-2 injections required | 🌎 NA |
- Hemorrhagic disorders: Commonly used before surgery where hemorrhage is anticipated.
- Hemorrhagic disorders: May also be used prophylactically when amprolium and sulfas are administered.
Caballos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Warfarin (or related compounds) toxicity | 500 mg SC q4-6h | SC | q4-6h | Until OSPT returns to normal | 🌎 NA |
| Warfarin (or related compounds) toxicity | 0.5-2.5 mg/kg IM, if IV use is necessary dilute in saline or D5W/saline and give very slowly (not to exceed 5 mg/minute) | IM, IV | — | — | 🌎 NA |
- Warfarin (or related compounds) toxicity: Whole blood or fresh plasma may also be necessary early in treatment.
- Warfarin (or related compounds) toxicity: Avoid IV if possible.
Ganado
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Anticoagulant rodenticide toxicity | Initially 0.5-2.5 mg/kg IV in D5W at a rate of 10 mg/minute. Subsequent doses may be given IM or SC. | IV, IM, SC | — | 3-4 weeks for second generation agents | 🌎 NA |
| Anticoagulant rodenticide toxicity | 0.5-2.5 mg/kg IM, if IV use is necessary dilute in saline or D5W/saline and give very slowly (not to exceed 5 mg/minute) | IM, IV | — | — | 🌎 NA |
| Acute hypoprothrombinemia with hemorrhage | 0.5-2.5 mg/kg IV, not to exceed 10 mg/minute in mature animals and 5 mg/minute in newborn and very young animals | IV | — | — | 🌎 NA |
| Non-acute hypoprothrombinemia | 0.5-2.5 mg/kg IM or SC | IM, SC | — | — | 🌎 NA |
| Sweet clover or lespedeza toxicity | 1-1.5 mg/kg SC for several days | SC | q24h | several days | 🌎 NA |
- Anticoagulant rodenticide toxicity: Avoid IV if possible.
- Sweet clover or lespedeza toxicity: Remove from source, avoid stress/injury.
Cerdos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Warfarin (or related compounds) toxicity | 0.5-2.5 mg/kg IM, if IV use is necessary dilute in saline or D5W/saline and give very slowly (not to exceed 5 mg/minute) | IM, IV | — | — | 🌎 NA |
- Warfarin (or related compounds) toxicity: Avoid IV if possible.
Ovejas
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Warfarin (or related compounds) toxicity | 0.5-2.5 mg/kg IM, if IV use is necessary dilute in saline or D5W/saline and give very slowly (not to exceed 5 mg/minute) | IM, IV | — | — | 🌎 NA |
- Warfarin (or related compounds) toxicity: Avoid IV if possible.
Cabras
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Warfarin (or related compounds) toxicity | 0.5-2.5 mg/kg IM, if IV use is necessary dilute in saline or D5W/saline and give very slowly (not to exceed 5 mg/minute) | IM, IV | — | — | 🌎 NA |
- Warfarin (or related compounds) toxicity: Avoid IV if possible.
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
La Fitonadiona (Vitamina K1) es una vitamina sintética liposoluble idéntica a la vitamina K1 que se encuentra de forma natural. Es un antídoto crítico en medicina veterinaria, utilizado principalmente para revertir las coagulopatías causadas por la ingestión de rodenticidas anticoagulantes (p. ej., warfarina, brodifacoum, bromadiolona).
Las aplicaciones clínicas clave incluyen:
- Toxicidad por rodenticidas anticoagulantes: El pilar del tratamiento. Los rodenticidas de segunda generación tienen una vida media muy larga, lo que a menudo requiere 3-4 semanas de suplementación continua con vitamina K1.
- Intoxicación por trébol dulce: Utilizada en rumiantes para tratar la toxicidad por dicumarol proveniente de trébol dulce mohoso.
- Enfermedad hepática: Utilizada como coadyuvante en insuficiencia hepática aguda u obstrucción biliar donde la absorción o utilización de vitamina K está alterada.
- Toxicidad por sulfaquinoxalina: Revierte los trastornos hemorrágicos asociados con este coccidiostato.
Perla clínica: La vitamina K1 (fitonadiona) es efectiva para estas toxicidades, mientras que la vitamina K3 (menadiona) es ineficaz y conlleva un mayor riesgo de toxicidad. La fitonadiona requiere de 6-12 horas para sintetizar nuevos factores de coagulación; por lo tanto, los pacientes con hemorragia activa requieren transfusiones inmediatas de plasma o sangre entera para proporcionar factores de coagulación activos.
Mecanismo de acción
Phytonadione is essential for the hepatic synthesis of Vitamin K-dependent coagulation factors (Factors II, VII, IX, and X).
- Mechanism: In the liver, inactive precursors of these factors require γ-carboxylation of their glutamic acid residues to become functional. This carboxylation is catalyzed by the enzyme γ-glutamyl carboxylase, which requires the reduced form of Vitamin K (Vitamin K hydroquinone) as a cofactor.
- The Vitamin K Cycle: During carboxylation, Vitamin K is oxidized to Vitamin K epoxide. The enzyme Vitamin K epoxide reductase (VKOR) recycles the epoxide back to the active hydroquinone form.
- Anticoagulant Rodenticides → inhibit VKOR, depleting active Vitamin K and halting the production of functional clotting factors. Exogenous phytonadione bypasses this blockade, providing the necessary substrate to resume factor synthesis.
Seguridad y advertencias
Contraindicaciones
- 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)
Efectos adversos
- 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)
Precauciones
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.
Interacciones farmacológicas
May decrease the numbers of Vitamin K-producing bacteria in the gut, though chronic therapy usually has no significant effect on phytonadione absorption.
Concomitant oral administration may reduce the GI absorption of oral Vitamin K.
Phytonadione directly antagonizes the anticoagulant effects of these drugs.
May prolong or enhance the effects of anticoagulants, thereby antagonizing some of the therapeutic effects of phytonadione.
Antagonizes the effects of vitamin K
Antagonizes the effects of vitamin K
Antagonizes the effects of vitamin K
Antagonizes the effects of vitamin K
Antagonizes the effects of vitamin K
Antagonizes the effects of vitamin K
Antagonizes the effects of vitamin K
Antagonizes the effects of vitamin K
Antagonizes the effects of vitamin K
Antagonizes the effects of vitamin K
Antagonizes the effects of vitamin K
May decrease gut flora production of vitamin K, though clinically minor when exogenous K1 is supplemented
May exacerbate bleeding tendencies through platelet inhibition
Monitorización
- Clinical efficacy (resolution or lack of hemorrhage, pale mucous membranes, weakness)
- One-stage prothrombin time (OSPT / PT)
- Proteins Induced by Vitamin K Absence (PIVKA)
- International Normalized Ratio (INR)
- Prothrombin time (PT) is the best method of monitoring therapy
- Prothrombin Time (PT) - typically normalizes within 12-24 hours of starting therapy
- Activated Partial Thromboplastin Time (aPTT)
- PIVKA (Proteins Induced by Vitamin K Absence or Antagonism)
- Clinical signs of bleeding (mucous membranes, heart rate, respiratory rate)
Farmacocinética
Vida media
Absorción
Absorbed from the GI tract via intestinal lymphatics, requiring bile salts. Oral absorption is significantly enhanced (4-5 times in dogs) when administered with fatty foods. SC or PO doses may be poorly absorbed in hypovolemic animals.
Distribución
Concentrates in the liver for a short period but is not appreciably stored in the liver or other tissues. Small amounts cross the placenta. Enters maternal milk.
Metabolismo
Rapidly metabolized in the liver to polar metabolites.
Eliminación
The exact elimination pathways of Vitamin K1 are not completely understood, but metabolites are excreted in bile and urine.
Sobredosis
Phytonadione is relatively non-toxic. It is highly unlikely that toxic clinical signs would result after a single overdosage. However, inappropriate routes of administration (like rapid IV injection) can cause severe anaphylactoid reactions regardless of the dose.
Productos disponibles
Formulaciones
- Oral capsules
- Oral chewable tablets
- Aqueous colloidal solution for injection
- Emulsion for injection
- Injectable: 10 mg/ml
- Oral: 50 mg tablets
- Nutraceuticals (containing small amounts)
- Injectable solution (10 mg/ml)
- Oral tablets (10 mg, 25 mg, 50 mg)
Veterinario
- Phytonadione Oral Capsules: 25 mg, 50 mg (K-Caps, Veda-K1, Veta-K1, Vitamin K1 Double Strength)
- Phytonadione Oral Tablets, Chewable: 25 mg, 50 mg (Vitamin K1 Chewable, K-Chews)
- Phytonadione Aqueous Colloidal Solution for Injection: 10 mg/mL (K-Ject, Veda-K1, Vita-Jec)
- Vitamine K1 Laboratoire TVM
- Konakion
- Vitamin K1 Injection (10 mg/ml)
- Vitamin K1 Tablets (10 mg, 50 mg)
Etiquetado para humanos
- Phytonadione Oral Tablets: 5 mg (Mephyton)
- Phytonadione Injection, Emulsion: 2 mg/mL & 10 mg/mL
- Konakion (Phytomenadione) injection (10 mg/ml)
- Konakion tablets (10 mg)
Estado regulador
Widely approved across EU member states for veterinary use.
Available as authorized veterinary medicines.
Sin datos reguladores para: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
Phytonadione is highly sensitive to light and must be protected from light at all times. Store tablets and capsules in well-closed, light-resistant containers. If used as an IV infusion, the container and tubing should be wrapped with an opaque material.
Información para el cliente
- Adherencia estricta al horario: Debido a que los venenos para ratas modernos (rodenticidas de segunda generación) permanecen en el cuerpo durante mucho tiempo, es fundamental administrar este medicamento durante todo el tiempo prescrito (a menudo 3-4 semanas). Suspender el tratamiento antes de tiempo puede provocar una hemorragia interna repentina que ponga en peligro la vida.
- Administrar con comida: Administre la vitamina K1 oral con una comida grasa (como comida enlatada para mascotas, una pequeña cantidad de queso o mantequilla de maní) para aumentar significativamente la cantidad de medicamento que se absorbe en el torrente sanguíneo.
- Restricción de ejercicio: Mantenga a su mascota tranquila y estrictamente confinada (solo paseos con correa, sin saltos ni juegos bruscos) durante el tratamiento para minimizar el riesgo de hematomas o hemorragias internas por golpes menores.
- Pruebas de seguimiento: Es probable que su veterinario necesite volver a verificar los tiempos de coagulación sanguínea de su mascota aproximadamente 48 horas después de la última dosis de vitamina K1 para asegurarse de que el veneno haya sido eliminado completamente de su sistema.
La referencia de medicamentos de VetSheet está destinada a profesionales veterinarios autorizados como ayuda para la toma de decisiones clínicas, no como sustituto del criterio profesional ni del prospecto actual del fabricante.