Naproxeno
Naproxen
También conocido como: Aleve · Anaprox · EC-Naprosyn · Midol Extended Relief · Naprelan · Equiproxen · naproxeneum · RS-3540 · RS-3650 · naproxen sodium
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 |
|---|---|---|---|---|---|
| Osteoarthritis and musculoskeletal inflammatory diseases (Last resort) | 2 mg/kg PO every other day (q48h) | PO | q48h | — | 🌎 NA |
- Osteoarthritis and musculoskeletal inflammatory diseases (Last resort): Because of the difficulty in accurately dosing naproxen and its potential for adverse effects, use only when FDA-approved and safer NSAIDs have been ineffective.
Pequeños mamíferos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Septic arthritis pain; inflammation (Rabbits) | 2.4 mg/mL in drinking water for 21 days | PO | Continuous | 21 days | 🌎 NA |
- Septic arthritis pain; inflammation (Rabbits): Dose specific to rabbits.
Caballos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Myositis and soft tissue diseases of the musculoskeletal system | 5 mg/kg by slow IV, then 10 mg/kg, PO (top dressed in feed) twice daily for up to 14 days or 10 mg/kg, PO (top dressed in feed) twice daily for up to 14 consecutive days. | IV, PO | q12h | Up to 14 days | 🌎 NA |
| Systemic therapies for joint disease | 10 mg/kg PO daily | PO | q24h | — | 🌎 NA |
- Myositis and soft tissue diseases of the musculoskeletal system: ARCI UCGFS Class 4 Drug. Veterinary product no longer commercially available.
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
El naproxeno es un fármaco antiinflamatorio no esteroideo (AINE) perteneciente a la clase del ácido propiónico, estructuralmente similar al ibuprofeno y al ketoprofeno.
- Uso veterinario: Su uso en medicina veterinaria ha sido reemplazado en gran medida por AINE más nuevos, seguros y con mayor selectividad por la COX-2.
- Riesgo de toxicidad: Es notoriamente tóxico para los perros debido a su vida media excepcionalmente larga (74 horas) y a su extensa recirculación enterohepática, lo que conlleva un índice terapéutico muy estrecho. Muchos clínicos desaconsejan enérgicamente su uso en perros.
- Uso en equinos: Anteriormente utilizado para el dolor musculoesquelético, miositis y enfermedades de tejidos blandos en caballos, pero el producto específico para uso veterinario (Equiproxen®) ya no se comercializa en los EE. UU.
Mecanismo de acción
Naproxen exerts its analgesic, anti-inflammatory, and antipyretic effects by inhibiting the cyclooxygenase (COX) enzymes.
- Arachidonic Acid → COX-1 and COX-2 inhibition → Decreased synthesis of prostaglandins and thromboxanes.
- The reduction in pro-inflammatory prostaglandins mitigates inflammation, pain, and fever.
- Because naproxen is a non-selective COX inhibitor, it also blocks the constitutive, protective prostaglandins (via COX-1) in the gastric mucosa and kidneys. This mechanism explains its high propensity for causing gastrointestinal ulceration and renal toxicity, particularly in sensitive species like dogs and cats.
Seguridad y advertencias
Contraindicaciones
- Active GI ulcers
- History of hypersensitivity to naproxen or other NSAIDs
- Pre-existing hematologic, renal, or hepatic disease
Efectos adversos
- GI distress (anorexia, vomiting, diarrhea)
- Gastrointestinal ulcers and perforation
- Melena and bloody vomitus
- Renal effects (nephritis, nephrotic syndrome, fluid retention)
- Hepatic effects (increased liver enzymes)
- Hematologic effects (hypoproteinemia, decreased hematocrit, anemia)
- CNS effects (neuropathies, lethargy, depression)
Precauciones
WARNING: Extremely narrow therapeutic index in dogs. Use is generally discouraged unless all FDA-approved, safer NSAIDs have failed.
- Relatively Contraindicated: Patients with a history of or pre-existing hematologic, renal, or hepatic disease.
- Caution: Use cautiously in patients with a history of GI ulcers or heart failure (may cause fluid retention).
- Infection: Animals suffering from inflammation secondary to concomitant infection should receive appropriate antimicrobial therapy alongside NSAID treatment.
Interacciones farmacológicas
Increased risk for nephrotoxicity
Increased risk for bleeding
Decreased plasma levels of naproxen and increased likelihood of GI adverse effects (blood loss). Concomitant use is not recommended.
May increase risk for GI ulceration
Concomitant administration significantly increases the risks for GI adverse effects and ulceration
Naproxen may reduce the saluretic and diuretic effects of furosemide
Potential displacement leading to increased serum levels and duration of action of the displaced drug
Serious toxicity has occurred; use together with extreme caution
May cause a significant increase in serum levels and half-life of naproxen
Monitorización
- Analgesic/anti-inflammatory efficacy
- GI signs: appetite, feces (occult blood, diarrhea)
- PCV (packed cell volume) and hematocrit if indicated or on chronic therapy
- WBCs if indicated or on chronic therapy
- Renal and hepatic function panels (especially in dogs)
Farmacocinética
Vida media
Absorción
Horses: 50% bioavailability after oral dosing; absorption is not altered by food. Dogs: Rapid oral absorption with 68-100% bioavailability.
Distribución
Highly bound to plasma proteins (99% in humans). Crosses the placenta and enters milk at about 1% of serum levels.
Metabolismo
Metabolized in the liver.
Eliminación
Detectable in the urine for at least 48 hours in the horse after an oral dose.
Sobredosis
Toxicity is a major concern, particularly in dogs and cats.
- Dogs: The reported oral LD50 is >1000 mg/kg, but clinical toxicity occurs at much lower doses.
- >5 mg/kg: Gastrointestinal signs and GI ulceration.
- >25 mg/kg (some dogs as low as 10 mg/kg): Significant renal damage.
- >50 mg/kg: Neurologic signs.
- Clinical Signs: Vomiting (often bloody), lethargy, anorexia, diarrhea, melena, anemia, and elevated renal/hepatic values.
- Treatment:
- Decontamination: Emesis and/or activated charcoal if recent ingestion.
- GI Protection: Misoprostol and sucralfate are recommended for 10-14 days post-exposure.
- Renal Protection: Fluid diuresis should be considered if renal effects are expected.
- Supportive Care: Monitor electrolyte and fluid balance carefully; manage renal failure using established guidelines.
Productos disponibles
Formulaciones
- Oral tablets
- Gelcaps
- Capsules
- Delayed/controlled-release tablets
- Oral suspension
- Injection (historically available for horses)
Veterinario
- None currently marketed in the USA (Equiproxen® is discontinued)
Etiquetado para humanos
- Naproxen Oral Tablets/Gelcaps/Capsules: 200 mg, 250 mg, 375 mg, 500 mg
- Naproxen Delayed/Controlled-release Tablets: 375 mg, 500 mg, 750 mg
- Naproxen Oral Suspension: 125 mg/5 mL
Estado regulador
Sin datos reguladores para: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
Store in well-closed, light-resistant containers at room temperature. Avoid temperatures above 40°C (104°F).
Información para el cliente
PELIGRO: Nunca administre analgésicos de venta libre para humanos como Aleve® a sus mascotas sin instrucciones explícitas de un veterinario. El naproxeno es altamente tóxico para perros y gatos.
- Si a su mascota le recetan naproxeno, siga estrictamente el programa de dosificación (que puede ser tan poco frecuente como cada dos días para los perros).
- Suspenda la medicación y contacte a su veterinario inmediatamente si observa:
- Pérdida de apetito o letargo/depresión
- Vómitos (especialmente si contienen sangre o parecen posos de café)
- Diarrea o heces negras y alquitranadas
- Cambios en los hábitos de consumo de agua o micción
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.