Mirtazapina
Mirtazapine
6-azamianserin, Org-3770, mepirzapine
También conocido como: Remeron SolTab · Zispin · Mirataz · 6-azamianserin · Org-3770 · mepirzapine · Mirtazapinum
Revisado por el equipo veterinario de VetSheetActualizado 5 abr 2026Referencia veterinaria basada en la evidencia
Evidencia posológica v13 auditada
Evidencia estructurada para el cálculoChemotherapy-induced anorexia
- q24-72h
NA
Contexto clínico obligatorio (2)
- Management of weight loss (label dosage; FDA-approved): Using the transdermal formulation, apply 1.5-inch ribbon (≈2 mg/cat) to the inner pinna of the cat’s ear every 24 hours for 14 days. 1 The person applying medication should wear gloves. Alternate application of ointment between the left and right inner pinnae of the ears.
- ■ This medicine may be given with or without food. If your animal vomits after receiving the medication on an empty stomach, give it with food or a small treat. If vomiting continues, contact your veterinarian.
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
La mirtazapina es un antidepresivo tetracíclico atípico ampliamente utilizado en medicina veterinaria, principalmente como un potente estimulante del apetito y antiemético para perros y gatos.
- Perla clínica: Es particularmente beneficiosa para pacientes con enfermedad renal crónica (ERC), insuficiencia cardíaca congestiva, trastornos gastrointestinales, enfermedad hepática o neoplasias, donde aborda tanto las náuseas como la inapetencia.
- Puede combinarse de forma segura con otros antieméticos para el vómito refractario o las náuseas y vómitos inducidos por quimioterapia (CINV).
- El principal efecto secundario que limita la dosis es la sedación, aunque en gatos se observa frecuentemente una excitación paradójica (vocalización, aumento del afecto).
Importante: Utilice siempre la dosis efectiva más baja para minimizar las propiedades sedantes. No exceda los 30 mg/día en perros, ya que dosis más altas pierden paradójicamente los efectos estimulantes del apetito.
Mecanismo de acción
Mirtazapine has a complex, multi-receptor pharmacological profile (often classified as a NaSSA - Noradrenergic and Specific Serotonergic Antidepressant):
- Central pre-synaptic α2-adrenergic receptors: Antagonism blocks the negative feedback loop → increases Norepinephrine (NE) release → stimulates appetite via other α-receptors.
- 5-HT3 receptors: Potent antagonism in the Chemoreceptor Trigger Zone (CRTZ) and GI tract → provides robust anti-nausea and antiemetic effects.
- 5-HT2 receptors: Antagonism contributes to its anxiolytic profile.
- H1 (Histamine) receptors: Potent antagonism → produces prominent sedative effects.
- Peripheral α1-adrenergic & Muscarinic receptors: Moderate antagonism → may cause occasional orthostatic hypotension and mild anticholinergic effects.
Seguridad y advertencias
Contraindicaciones
- Hypersensitivity to mirtazapine
- Use of monoamine oxidase inhibitors (MAOIs, e.g., selegiline) within the past 14 days
- Pre-existing haematological disease
Efectos adversos
- Drowsiness/sedation
- Increased affection (cats)
- Hypotension
- Tachycardia
- Sedation (common and can be profound)
- Increased vocalization (especially in cats)
- Altered behavior and increased interaction with others
- Blood dyscrasias (reported in humans)
Precauciones
Use with caution in patients with known cardiac disease or cerebrovascular disease that could be exacerbated by hypotension.
- Monitor patients with renal impairment, renal failure, or hepatic disease closely, as clearance may be reduced.
- Use with caution in patients with diabetes mellitus, as antidepressants may indirectly affect blood glucose concentrations.
- Due to weak anticholinergic activity, use vigilance in patients susceptible to these effects (e.g., urinary retention, prostatic hypertrophy, acute closed-angle glaucoma, increased intraocular pressure, GI obstruction, or ileus).
- May impair concentration and alertness in active animals.
- Use cautiously in patients with pre-existing hematological disease (leukopenia, neutropenia, thrombocytopenia), as it has been rarely associated with blood dyscrasias in humans.
Interacciones farmacológicas
Mirtazapine may cause increases in blood pressure
Minimal effects on mirtazapine blood levels, but may cause additive impairment of motor skills
May cause increased serum concentrations of mirtazapine
Increased risk for serotonin syndrome
Increased risk for serotonin syndrome; MAO inhibitors considered contraindicated with mirtazapine
Increased risk for serotonin syndrome
Increased risk of serotonin syndrome
Monitorización
- Increased appetite
- Decreased episodes of vomiting
- Weight gain
- Adverse effects (sedation, vocalization, tachycardia)
- Appetite and body weight
- Behavioral changes (sedation, vocalization)
- Complete blood count (due to human risk of blood dyscrasias)
- Hepatic and renal function parameters
Farmacocinética
Vida media
Absorción
Rapidly and completely absorbed following oral administration. Food has minimal effects on rate and extent of absorption. Oral bioavailability is about 20% for dogs and 50% for humans.
Distribución
Plasma protein binding is approximately 70-72% for dogs, mice, and rats.
Metabolismo
Metabolized via multiple pathways including 8-hydroxylation, N-oxidation, and demethylation followed by conjugation. Cats have a limited capacity for glucuronidation, leading to less rapid clearance and requiring extended dosing intervals.
Eliminación
Elimination occurs primarily via urine (75%) and feces (15%). Renal or hepatic impairment may reduce clearance.
Sobredosis
Ingestion of upwards of 10-fold to 30-fold the therapeutic dose in humans exhibits minimal toxicity requiring no acute intervention other than observation.
Treatment: Despite the wide safety margin, standard overdose protocols (including the administration of activated charcoal) and monitoring are recommended in acute overdose situations.
Productos disponibles
Formulaciones
- Oral Tablets
- Orally Disintegrating Tablets (ODT)
- 15 mg tablets
- 15 mg/ml oral solution
- Transdermal formulation (named patient basis / authorized veterinary preparations)
Veterinario
- None
- Mirataz 20 mg/g transdermal ointment
Etiquetado para humanos
- Mirtazapine Oral Tablets: 7.5 mg, 15 mg, 30 mg & 45 mg (Remeron, generic)
- Mirtazapine Orally Disintegrating Tablets: 15 mg, 30 mg & 45 mg (Remeron SolTab, generic)
- Zispin 15 mg tablets
- Zispin 15 mg/ml oral solution
Estado regulador
Mirataz transdermal ointment is authorized for cats.
Mirataz transdermal ointment is authorized for cats.
Sin datos reguladores para: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
Store coated and orally disintegrating tablets at 25°C (77°F) with excursions permitted to 15-30°C (59-86°F). Protect from light and moisture. Orally disintegrating tablets should be used immediately once removed from the blister pack.
Información para el cliente
- Administración: Administre exactamente según lo prescrito. Puede administrarse con o sin alimentos.
- Comprimidos de desintegración oral (ODT): Si utiliza los comprimidos que se disuelven, asegúrese de que sus manos estén completamente secas antes de manipularlos. Coloque el comprimido debajo de la lengua de su mascota y mantenga su boca cerrada durante unos segundos hasta que se disuelva. Ofrézcale agua inmediatamente después.
- Qué esperar: Debería observar una mejora en el apetito y una disminución de los vómitos.
- Efectos secundarios a reportar: Contacte a su veterinario si nota somnolencia excesiva, debilidad severa, frecuencia cardíaca rápida o comportamiento inusual.
Nota para propietarios de gatos: Es muy común que los gatos se vuelvan inusualmente vocales (maullidos fuertes) o excesivamente cariñosos después de tomar este medicamento. Por lo general, esto es inofensivo, pero informe a su veterinario si se vuelve disruptivo.
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.