Hidroxicina
Hydroxyzine
Hydroxyzine hydrochloride, Hydroxyzine pamoate
También conocido como: Atarax · Vistaril · Masmoran · Ucerax · Hydroxyzine embonate · Hydroxyzine pamoate · Hydroxyzine HCl · Hydroxyzini HCl · Hydroxyzine hydrochloride
Revisado por el equipo veterinario de VetSheetActualizado 5 abr 2026Referencia veterinaria basada en la evidencia
Evidencia posológica v13 auditada
Evidencia estructurada para el cálculoAntipruritic/antihistamine (extra-label)
- q8-12h
NA
Contexto clínico obligatorio (2)
- ■ This medicine may be given with or without food. If your animal drools, vomits, or acts sick after receiving this medicine on an empty stomach, give with food or a small treat to see if this helps.
- Hydroxyzine oral products should be stored in tight, light-resistant containers at room temperature 20°C to 25°C (68°F-77°F). Hydroxyzine injection should be stored protected from light at room temperature 20°C to 25°C (68°F-77°F) with excursions permitted to 15°C to 30°C (59°F-86°F). Avoid freezing all liquid products.
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
La hidroxicina es un antihistamínico derivado de la piperazina de primera generación ampliamente utilizado en medicina veterinaria. Se prescribe principalmente por sus propiedades antipruriginosas y antihistamínicas, lo que lo convierte en un pilar en el manejo de la dermatitis atópica, la dermatitis alérgica por picadura de pulgas y otras afecciones alérgicas en perros y gatos.
Debido a que atraviesa fácilmente la barrera hematoencefálica, también proporciona efectos sedantes y tranquilizantes, lo cual puede ser altamente beneficioso para animales ansiosos o con prurito intenso que se automutilan. En gatos, se utiliza ocasionalmente para manejar la enfermedad del tracto urinario inferior felino (FLUTD) idiopática recurrente debido a sus propiedades antiespasmódicas y ansiolíticas leves.
Mecanismo de acción
Hydroxyzine acts as a competitive antagonist at H1-receptors on effector cells.
- Histamine Blockade: Competes with histamine for H1-receptor sites → prevents histamine-induced bronchoconstriction, vasodilation, and capillary permeability. Note: It does not inhibit the release of histamine from mast cells, but antagonizes its effects.
- CNS Effects: Readily crosses the blood-brain barrier → binds to central H1 receptors → causes sedation and tranquilization.
- Additional Properties: Exhibits anticholinergic, antispasmodic, local anesthetic, mild bronchodilative, and antiemetic activities.
- Metabolism Pearl: In vivo, hydroxyzine is metabolized in the liver to its active metabolite, cetirizine, which contributes significantly to its prolonged antihistaminic effects.
Seguridad y advertencias
Contraindicaciones
- Hypersensitivity to hydroxyzine or its metabolites (e.g., cetirizine)
- Known hypersensitivity to hydroxyzine or cetirizine
- Early pregnancy (teratogenic in some animal models)
Efectos adversos
- Sedation (most common, usually mild and transient in dogs)
- Hyperexcitability (occasional paradoxical reaction)
- Fine rapid tremors (dogs)
- Whole body tremors (dogs)
- Seizures (rare in dogs)
- Polydipsia (cats)
- Depression (cats)
- Behavioral changes (cats)
- Sedation / Lethargy
- Dry mouth
- Urinary retention
- Gastrointestinal upset
- Paradoxical excitation (rare)
Precauciones
Use with caution in patients with prostatic hypertrophy, bladder neck obstruction, severe cardiac failure, angle-closure glaucoma, or pyeloduodenal obstruction due to its anticholinergic effects.
Pregnancy Warning: At doses substantially greater than those used therapeutically, hydroxyzine has been shown to be teratogenic in lab animals. Use during pregnancy (particularly during the first trimester) only when the benefits outweigh the risks (FDA Category C). It is unknown if hydroxyzine enters maternal milk, but its active metabolite cetirizine does.
Interacciones farmacológicas
Additive anticholinergic effects may occur when used concomitantly.
Additive CNS depression may be seen.
Hydroxyzine may inhibit or reverse the vasopressor effects of epinephrine; use norepinephrine or metaraminol instead.
Additive CNS depression and sedation
Monitorización
- Efficacy (reduction in pruritus or clinical signs)
- Adverse effects (degree of sedation, excitability, or behavioral changes)
- Resolution of pruritus or allergic signs
- Adverse anticholinergic effects (e.g., monitoring urination)
Farmacocinética
Vida media
Absorción
Rapidly and well absorbed after oral administration.
Distribución
Readily crosses the blood-brain barrier. It is unknown if hydroxyzine enters maternal milk, but its active metabolite cetirizine has been detected in milk.
Metabolismo
Apparently metabolized in the liver (to its active metabolite, cetirizine).
Eliminación
Effects generally persist for 6-8 hours in dogs and up to 12 hours in cats.
Sobredosis
Overdoses would be expected to cause increased sedation and perhaps hypotension. At high doses, fine rapid tremors and rarely seizures have been reported.
Common clinical signs of toxicity in dogs include:
- Hyperthermia
- Lethargy
- Tachycardia
- Trembling / Tremors
- Ataxia
- Somnolence
Treatment: There are no specific antidotes available. Gut emptying protocols should be considered with large or unknown quantity overdoses. Supportive and symptomatic treatment is recommended if necessary.
Productos disponibles
Formulaciones
- Oral Tablets
- Oral Syrup
- Injection
- Oral Capsules
- Oral Suspension
- 10 mg tablet
- 25 mg tablet
- 2 mg/ml syrup
Etiquetado para humanos
- Hydroxyzine HCl Oral Tablets: 10 mg, 25 mg, & 50 mg
- Hydroxyzine HCl Oral Syrup: 10 mg/5 mL
- Hydroxyzine HCl Injection: 25 mg/mL & 50 mg/mL
- Hydroxyzine Pamoate Oral Capsules: 25 mg, 50 mg, & 100 mg
- Hydroxyzine Pamoate Suspension: 25 mg/5 mL
- Atarax 10 mg tablets
- Atarax 25 mg tablets
- Ucerax 2 mg/ml syrup
Estado regulador
Classified as POM (Prescription Only Medicine).
Classified as POM (Prescription Only Medicine).
Sin datos reguladores para: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
Hydroxyzine oral products should be stored at room temperature in tight, light-resistant containers. Avoid freezing all liquid products.
Información para el cliente
- La somnolencia es común: Su mascota puede parecer adormilada o letárgica, especialmente al comenzar el tratamiento. Esto es normal, pero contacte a su veterinario si parece excesivo.
- Perros de trabajo: Este medicamento puede afectar el rendimiento y el estado de alerta de perros de trabajo, de caza o de servicio.
- La constancia es clave: Los antihistamínicos suelen funcionar mejor cuando se administran de forma constante para prevenir los brotes alérgicos en lugar de tratarlos una vez que son graves.
- Pruebas de alergia: Si su mascota tiene programada una prueba de alergia intradérmica, deberá suspender este medicamento de 3 a 7 días antes. Consulte a su veterinario para conocer el tiempo exacto.
- No duplique la dosis: Si olvida una dosis, adminístrela cuando lo recuerde, pero nunca dé dos dosis a la vez.
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.