Nitazoxanida
Nitazoxanide
Nitrothiazolyl-salicylamide derivative
También conocido como: Alinia · Navigator · Daxon · Heliton · PH-5776 · desacetyl-nitazoxanide (active metabolite tizoxanide)
Revisado por el equipo veterinario de VetSheetActualizado 5 abr 2026Referencia veterinaria basada en la evidencia
Evidencia posológica v13 auditada
Evidencia estructurada para el cálculoGiardia spp associated diarrhea (extra-label)
Requiere verificación veterinaria
- once
NA
Contexto clínico obligatorio (1)
- The human-approved powder for oral suspension should be stored at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F-86°F). Once suspended with tap water, the oral suspension should be kept in tightly closed containers at room temperature and discarded after 7 days.
Cryptosporidia spp associated diarrhea (extra-label)
Requiere verificación veterinaria
- once
NA
Contexto clínico obligatorio (1)
- The human-approved powder for oral suspension should be stored at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F-86°F). Once suspended with tap water, the oral suspension should be kept in tightly closed containers at room temperature and discarded after 7 days.
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
Nitazoxanida es un agente antiparasitario y antibacteriano de amplio espectro perteneciente a la clase de las tiazolidas.
Aspectos clínicos destacados:
- Amplio espectro: Presenta actividad contra una amplia variedad de protozoos (incluyendo Sarcocystis neurona, Giardia, Cryptosporidium), nematodos, trematodos y bacterias anaerobias (p. ej., Helicobacter pylori).
- Uso en equinos: Históricamente aprobada por la FDA como pasta oral (Navigator®) para la mieloencefalitis protozoaria equina (EPM), aunque este producto ha sido retirado del mercado estadounidense.
- Uso en animales pequeños: Existe un interés considerable en su uso fuera de etiqueta (off-label) para infecciones refractarias por Cryptosporidium y Giardia en perros y gatos. Sin embargo, su utilidad clínica en animales pequeños suele verse limitada por efectos adversos gastrointestinales significativos (especialmente en perros).
- Uso en humanos: Aprobada por la FDA para el tratamiento de la diarrea causada por Cryptosporidium parvum y Giardia lamblia en humanos, donde generalmente es muy bien tolerada.
Mecanismo de acción
Nitazoxanide acts as a prodrug and is rapidly converted into its active metabolites, tizoxanide and tizoxanide glucuronide.
- Mechanism: It inhibits the pyruvate:ferredoxin oxidoreductase (PFOR) enzyme-dependent electron transfer reactions.
- Pathway: Inhibition of PFOR → disruption of essential anaerobic energy metabolism → death of susceptible protozoa and anaerobic bacteria.
- Unlike nitroimidazoles (e.g., metronidazole), nitazoxanide does not appear to cause DNA damage, reducing its mutagenic potential.
Seguridad y advertencias
Contraindicaciones
- Horses less than 1 year of age
- Horses that are sick or debilitated for reasons other than EPM
- Use with extreme caution in stallions and horses predisposed to laminitis
- Animals with compromised renal or hepatic function (safety not established)
Efectos adversos
- Horses: Fever, anorexia, lethargy/depression, decreased gut sounds, diarrhea/enterocolitis, colic, laminitis, head/limb edema
- Horses: 'Treatment crisis' (CNS inflammation secondary to dying protozoa)
- Dogs: Excessive salivation, vomiting, diarrhea (often therapy-limiting)
- Humans: Yellow discoloration of sclera (rare, reversible)
Precauciones
Use with caution in animals with compromised renal or hepatic function. In horses, monitor closely for signs of enterocolitis (disruption of normal flora) and laminitis (stallions may be more prone). A 'treatment crisis' may occur in horses during the first two weeks of EPM therapy due to CNS inflammation from dying protozoa, which may require anti-inflammatory therapy. Not evaluated in horses weighing > 1200 lbs.
Interacciones farmacológicas
Use with caution; tizoxanide is >99% protein bound and may displace or be displaced by other highly bound drugs, potentially altering free drug concentrations.
Monitorización
- Clinical efficacy (resolution of diarrhea or neurological signs)
- Weekly body weight
- Adverse reactions (GI upset, hypersalivation)
- If adverse reactions occur: Physical exam, CBC, serum albumin, total serum protein
Farmacocinética
Vida media
Absorción
Absorbed orally and rapidly converted to the active metabolite tizoxanide (desacetyl-nitazoxanide).
Distribución
More than 99% of tizoxanide is bound to plasma proteins.
Metabolismo
Rapidly hydrolyzed to tizoxanide, which is further conjugated to tizoxanide glucuronide.
Eliminación
Tizoxanide is excreted in the urine, bile, and feces; the glucuronide metabolite is secreted in the urine and bile.
Sobredosis
Information on acute toxicity is limited.
- Horses: Overdoses of 2.5X have been associated with fatalities. Doses of ~5X labeled dose caused anorexia, diarrhea, and lethargy within 4 days.
- Dogs/Cats: Oral LD50 is > 10 g/kg.
- Rats: Repeated doses of 450 mg/kg caused intense salivation and increased liver/spleen weights.
- Humans: Doses up to 4 grams have been taken without significant adverse effects.
Treatment: In the event of an overdose, observe the patient closely and provide supportive care.
Productos disponibles
Formulaciones
- Oral Tablets
- Powder for Oral Suspension
- Oral Paste (Veterinary - Withdrawn)
Veterinario
- Nitazoxanide oral paste (32%); Navigator® (FDA approval withdrawn; no longer marketed)
Etiquetado para humanos
- Nitazoxanide Oral Tablets: 500 mg; Alinia®
- Nitazoxanide Powder for Oral Suspension: 20 mg/mL (100 mg/5 mL after reconstitution); Alinia®
Estado regulador
Sin datos reguladores para: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
Store the human-approved powder for oral suspension at 25°C (77°F); excursions permitted to 15-30°C (59-86°F). Once reconstituted with tap water, keep the oral suspension in tightly closed containers at room temperature and discard after 7 days.
Información para el cliente
Nota importante para los propietarios de mascotas: La nitazoxanida no se utiliza comúnmente en perros y gatos, y se considera un tratamiento 'fuera de etiqueta' (off-label) en medicina veterinaria.
- Efectos secundarios: En perros y gatos, este medicamento puede causar malestar estomacal significativo, incluyendo babeo excesivo (hipersalivación), vómitos y diarrea. Si esto ocurre, comuníquese con su veterinario, ya que es posible que deba suspenderse el medicamento.
- Administración: Siga exactamente las instrucciones de dosificación de su veterinario. No ajuste la dosis sin consultarlo.
- Monitoreo: Vigile el apetito, los niveles de energía y el peso corporal de su mascota durante el tratamiento.
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.