Leucovorina cálcica
Leucovorin Calcium
5-formyl tetrahydrofolic acid
También conocido como: Citrovorum factor · 5-formyl tetrahydrofolate · citrovorin · folidan · FTHF · NSC-3590 · calcium folinate · calcifolin · calfonat · folinic acid calcium salt
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 |
|---|---|---|---|---|---|
| Folate deficiency associated with pyrimethamine use | 5-15 mg (total dose) PO or parenterally once daily | PO/Parenteral | q24h | — | 🌎 NA |
| Methotrexate overdose | 25-200 mg/m2 parenterally every 6 hours until methotrexate levels are less than 1 X 10 -8 M | Parenteral | q6h | Until methotrexate levels are < 1 X 10^-8 M | 🌎 NA |
- Methotrexate overdose: Most effective if given within 48 hours of overdose. Dose is dependent on serum methotrexate concentration.
Gatos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Folate deficiency associated with pyrimethamine use | 5-15 mg (total dose) PO or parenterally once daily | PO/Parenteral | q24h | — | 🌎 NA |
| Bone marrow suppression associated with pyrimethamine or trimethoprim/sulfa | 5 mg once daily | Not specified | q24h | — | 🌎 NA |
| To prevent bone marrow toxicity associated with pyrimethamine | 1 mg/kg once daily | Not specified | q24h | — | 🌎 NA |
| Methotrexate overdose | 25-200 mg/m2 parenterally every 6 hours until methotrexate levels are less than 1 X 10 -8 M | Parenteral | q6h | Until methotrexate levels are < 1 X 10^-8 M | 🌎 NA |
- Methotrexate overdose: Most effective if given within 48 hours of overdose.
Caballos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Macrocytic anemia and neutropenia associated with pyrimethamine and/or trimethoprim (especially in pregnant mares) | 0.1-0.3 mg/kg PO once daily | PO | q24h | — | 🌎 NA |
- Macrocytic anemia and neutropenia associated with pyrimethamine and/or trimethoprim (especially in pregnant mares): A more practical approach would be to ensure that the horse receives green hay or pasture (high tetrahydrofolate levels in green roughage).
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
La leucovorina cálcica (también conocida como ácido folínico o factor citrovorum) es un derivado del ácido fólico reducido utilizado principalmente en medicina veterinaria como agente de rescate o antídoto.
- Indicación principal: Se utiliza para revertir o prevenir la toxicidad hematológica (como la supresión de la médula ósea, anemia macrocítica y neutropenia) asociada con inhibidores de la dihidrofolato reductasa (p. ej., pirimetamina, trimetoprima u ormetoprima).
- Rescate de metotrexato: Aunque se utiliza habitualmente en medicina humana como agente de rescate para la quimioterapia con dosis altas de metotrexato, rara vez se usa con este fin en medicina veterinaria, excepto en casos de sobredosis accidental de metotrexato.
- Nota clínica: A diferencia del ácido fólico estándar, la leucovorina no requiere la enzima dihidrofolato reductasa para ser biológicamente activa. Esto le permite eludir el bloqueo enzimático causado por los antagonistas del ácido fólico, suministrando directamente los folatos necesarios para la función celular.
Mecanismo de acción
Leucovorin is a reduced form of folic acid that acts as a direct coenzyme in cellular metabolism.
- Bypassing DHFR: It does not require conversion by dihydrofolate reductase (DHFR) to become biologically active.
- Active Metabolite: It is converted in the body to active reduced forms, predominantly 5-methyltetrahydrofolate (5-methyl THF).
- DNA Synthesis: These reduced folates act as coenzymes in the synthesis of purine and pyrimidine nucleotides → essential for DNA synthesis and the maintenance of normal erythropoiesis (red blood cell production).
- Enzyme Inhibition: Leucovorin inhibits thymidylate synthase by stabilizing the binding of fluorodeoxyuridylic acid to the enzyme. This mechanism potentiates both the antineoplastic activity and the toxicity of fluorouracil (5-FU).
Seguridad y advertencias
Contraindicaciones
- Known intolerance or hypersensitivity to leucovorin
Efectos adversos
- Gastrointestinal effects (noted in humans with oral administration)
- Seizures (very rare, noted in humans)
- Hypersensitivity reactions (very rare, noted in humans)
Precauciones
Use with extreme caution in patients receiving systemic fluorouracil. Because of its calcium content, large intravenous doses should be given slowly and not bolused. In humans, folinic acid therapy may mask the signs associated with cobalamin (B-12) deficiency in megaloblastic anemias. When reconstituting powder with bacteriostatic water (which contains benzyl alcohol), avoid use in neonates or very small animals.
Interacciones farmacológicas
Large doses of leucovorin may reduce the antiseizure efficacy of these agents.
Leucovorin may increase both the antineoplastic efficacy and toxicity of 5-FU.
Leucovorin may reduce their efficacy somewhat; however, protozoa cannot utilize leucovorin, preserving the antimicrobial effect against them.
Monitorización
- Complete Blood Count (CBC)
- Methotrexate serum levels (if used for methotrexate overdoses; may require contacting a local human hospital)
Farmacocinética
Vida media
Absorción
In humans, oral bioavailability is dose-dependent (97% at 25 mg, decreasing to 37% at 100 mg). IM bioavailability is similar to IV. Peak levels of active reduced folates occur 1.7-2.4 hours after oral dosing, and about 10 minutes after IV administration.
Distribución
Apparent volume of distribution for both L- and D-forms is about 0.6 L/kg in dogs. About 50% of oral body stores of reduced folates are found in the liver.
Metabolismo
Extensively metabolized to active reduced forms, predominantly 5-methyltetrahydrofolate (5-methyl THF).
Eliminación
Excreted into the urine, primarily as 10-formyl-THF or 5,10-methyl-THF.
Sobredosis
Except in situations where drug interactions are possible (e.g., with fluorouracil or antiseizure medications), an inadvertent overdose is unlikely to be of clinical concern.
Productos disponibles
Formulaciones
- Oral tablets
- Injection solution
- Powder for injection
Etiquetado para humanos
- Leucovorin Calcium Oral Tablets: 5 mg, 15 mg, & 25 mg
- Leucovorin Calcium Injection Solution: 10 mg/mL in 5 mg single dose vials
- Leucovorin Calcium Powder for Injection: 50 mg, 100 mg, 200 mg & 350 mg in vials
Estado regulador
Sin datos reguladores para: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
Tablets and powder for injection should be stored below 40°C (preferably between 15-30°C) in a well-closed container and protected from light. Injection solution should be refrigerated between 2-8°C and protected from light. Reconstituted solutions made with sterile water should be used immediately; those made with bacteriostatic water are stable up to 7 days. IV solutions in LRS, Ringer's, or 0.9% NaCl are stable up to 24 hours at room temperature. Not compatible with fluorouracil solutions.
Información para el cliente
Importante: Si este medicamento se está utilizando para tratar la toxicidad por metotrexato, solo debe administrarse en un entorno hospitalario bajo estricta supervisión veterinaria.
- Administración: La leucovorina oral puede administrarse con o sin alimentos.
- Adherencia estricta: Es fundamental seguir el programa de dosificación exacto prescrito por su veterinario. Omitir dosis puede comprometer el tratamiento o la prevención de anomalías graves en las células sanguíneas (toxicidad hematológica).
- Dosis omitidas: Si olvida una dosis, comuníquese con su veterinario para recibir instrucciones. No duplique las dosis sin orientación profesional.
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.