Paroxetina
Paroxetine
Paroxetine HCl
También conocido como: Paxil CR · Pexeva · Seroxat · BRL-29060 · FG-7051 · Paroxetine hydrochloride · Paroxetina · Paroxetinum
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 |
|---|---|---|---|---|---|
| Compulsive disorders | 1 mg/kg (up to 3 mg/kg) PO once daily (q24h) | PO | q24h | — | 🌎 NA |
| Generalized anxiety disorder | 1-1.5 mg/kg q24h | PO | q24h | — | 🌎 NA |
| Adjunctive treatment of phobias, fears, and anxieties | 0.5-1 mg/kg PO once daily | PO | q24h | — | 🌎 NA |
| Generalized anxiety and impulsivity | 1-2 mg/kg | PO | q24h | Long-term as needed | 🌍 EU |
- Generalized anxiety and impulsivity: Fluoxetine or clomipramine may be preferable due to authorized veterinary status.
Gatos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| SSRI responsive behavior problems | 0.5-1 mg/kg q24h (2.5-5 mg per cat q24h) | PO | q24h | — | 🌎 NA |
| Compulsive disorders | 0.5-1 mg/kg PO once daily (q24h) | PO | q24h | — | 🌎 NA |
| Generalized anxiety disorder | 0.5-1.5 mg/kg q24h | PO | q24h | — | 🌎 NA |
| Marking | 0.5-1 mg/kg PO once daily | PO | q24h | — | 🌎 NA |
| Intercat aggression | 0.5-1 mg/kg PO once daily | PO | q24h | — | 🌎 NA |
| SSRI responsive behavior problems | 0.5-1.5 mg/kg PO q24-48h | PO | q24-48h | — | 🌎 NA |
| Urine marking (especially with overt aggression) | 0.5-1 mg/kg | PO | q24h | Long-term as needed | 🌍 EU |
- Urine marking (especially with overt aggression): Can be increased to 2 mg/kg PO q24h but close monitoring is required. Monitor urination frequency.
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
La paroxetina es un potente inhibidor selectivo de la recaptación de serotonina (ISRS) utilizado fuera de indicación (off-label) en medicina veterinaria principalmente para la modificación de la conducta. Está estructuralmente relacionada con la fluoxetina, pero posee propiedades farmacocinéticas y farmacodinámicas distintas.
- Perros: Se utiliza para tratar la agresividad, comportamientos estereotipados, trastornos obsesivo-compulsivos (TOC) y ansiedad generalizada.
- Gatos: Es beneficiosa para el manejo del marcaje urinario, la agresividad entre gatos y los trastornos del sueño relacionados con la ansiedad.
Perla clínica: En comparación con la fluoxetina, la paroxetina tiene una vida media más corta y no posee metabolitos activos, lo que puede permitir un periodo de lavado (washout) más rápido si aparecen efectos adversos. Sin embargo, también posee propiedades anticolinérgicas leves, lo que hace que el estreñimiento sea un efecto secundario más común, particularmente en felinos.
Mecanismo de acción
Paroxetine acts by selectively blocking the serotonin transporter (SERT) on the presynaptic neuronal membrane in the central nervous system.
- Inhibition of SERT → Decreased reuptake of serotonin (5-HT) from the synaptic cleft → Increased concentration and prolonged activity of 5-HT at postsynaptic 5-HT receptors.
- This potentiation of serotonergic neurotransmission helps regulate mood, anxiety, and compulsive behaviors.
- Paroxetine has minimal affinity for dopamine or norepinephrine receptors, but does exhibit mild affinity for muscarinic acetylcholine receptors, contributing to its anticholinergic side effect profile.
Seguridad y advertencias
Contraindicaciones
- Patients with known hypersensitivity to paroxetine
- Patients receiving monoamine oxidase inhibitors (MAOIs)
- Known hypersensitivity to paroxetine or other SSRIs
- History of seizures or epilepsy
- Concurrent use of Monoamine Oxidase Inhibitors (MAOIs)
- Concurrent use of other serotonergic agents (due to serotonin syndrome risk)
Efectos adversos
- Anorexia (common, usually transient)
- Lethargy
- GI effects
- Irritability
- Insomnia/hyperactivity
- Panting
- Aggressive behavior in previously unaggressive dogs
- Constipation (especially in cats)
- Changes in elimination patterns
- Changes in blood glucose levels
- Reduced seizure threshold
- Decreased appetite
- Vomiting
- Trembling
- Restlessness
- Gastrointestinal disturbance
- Paradoxical increase in anxiety
- Potential increase in aggression
- Changes in urination frequency (cats)
Precauciones
Use with caution in patients with seizure disorders, or severe cardiac, hepatic, or renal disease. Dosages may need to be reduced in patients with severe hepatic or renal impairment.
If paroxetine is rapidly discontinued, withdrawal reactions can occur. If the patient has been receiving the drug for an extended period, a gradual withdrawal is recommended. Safety during pregnancy has not been established (FDA Category C in humans); use caution in nursing patients as the drug is excreted into milk at low levels.
Interacciones farmacológicas
Increased risk for serotonin syndrome
May increase paroxetine levels
May decrease or reverse the effects of SSRIs
Paroxetine (in humans) can decrease digoxin AUC by 15%
May alter insulin requirements
Increased risk for serotonin syndrome
High risk for serotonin syndrome; use contraindicated. A 5-week washout period is required after discontinuing paroxetine, and a 2-week washout if discontinuing the MAOI first.
Serotonin syndrome-like adverse effects possible
May decrease paroxetine levels
Increased plasma levels of phenytoin possible; may decrease paroxetine levels
Paroxetine may increase these beta-blockers' plasma levels and cause hypotension; atenolol may be safer
SSRIs can inhibit the metabolism of tramadol to active metabolites, decreasing efficacy and increasing toxicity risk (serotonin syndrome, seizures)
Paroxetine may increase TCA blood levels and may increase the risk for serotonin syndrome
Increased plasma levels of theophylline possible
Paroxetine may increase the risk for bleeding
High risk of fatal serotonin syndrome. Do not use paroxetine within 2 weeks of an MAOI, and do not use an MAOI within 6 weeks of stopping paroxetine.
Paroxetine antagonizes the effects of anticonvulsants and lowers the seizure threshold.
May lower seizure threshold and increase risk of adverse neurological events.
Increased risk of bleeding in the case of tissue trauma.
Increased risk of bleeding.
Increased risk of serotonin syndrome. Use only in exceptional cases with careful monitoring.
Monitorización
- Efficacy of behavioral modification
- Adverse effects (including appetite and weight changes)
- Behavioral changes (efficacy, paradoxical anxiety, or increased aggression)
- Frequency of urination (especially in cats)
- Signs of serotonin syndrome (tremors, agitation, hyperthermia)
- Gastrointestinal tolerance (appetite, vomiting)
Farmacocinética
Vida media
Absorción
No veterinary data located. In humans, slowly but nearly completely absorbed from the GI tract. High first-pass effect means relatively small amounts reach systemic circulation unchanged. Food does not impair absorption.
Distribución
About 95% bound to plasma proteins.
Metabolismo
Extensively metabolized, probably in the liver.
Eliminación
Excreted primarily in urine as metabolites, with some fecal excretion.
Sobredosis
Experience with overdoses in humans yields a mixed picture; while not as toxic as tricyclic antidepressants, fatalities and significant morbidity have occurred.
- Clinical Signs: ASPCA APCC data (2008-2009) reported common findings in dogs including hyperactivity, lethargy, mydriasis, and trembling. In cats, mydriasis was commonly noted.
- Treatment: In small animal overdoses, err on the safe side. Employ gut evacuation (if not contraindicated) followed by supportive care. Activated charcoal is very effective in binding paroxetine.
- Serotonin Syndrome: If serotonin syndrome develops, phenothiazines and cyproheptadine can be effective for control. Contact an animal poison control center for additional guidance.
Productos disponibles
Formulaciones
- Controlled-release oral tablets
- Oral suspension
- 20 mg oral tablet
- 30 mg oral tablet
- 2 mg/ml oral liquid suspension
Etiquetado para humanos
- Paroxetine Oral Tablets: 10 mg, 20 mg, 30 mg & 40 mg; Paxil® (GlaxoSmithKline); Pexeva® (Synthon); generic; (Rx)
- Paroxetine Oral Tablets Controlled-release: 12.5 mg, 25 mg & 37.5 mg; Paxil® CR (GlaxoSmithKline); generic; (Rx)
- Paroxetine Oral Suspension: 2 mg/mL in 250 mL; Paxil® (GlaxoSmithKline); generic; (Rx)
- Paxil 20 mg, 30 mg tablets
- Seroxat 20 mg, 30 mg tablets
- Seroxat 2 mg/ml oral suspension
Estado regulador
POM (Prescription Only Medicine). Used under the prescribing cascade.
POM (Prescription Only Medicine). Used under the prescribing cascade.
Sin datos reguladores para: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
Paroxetine oral tablets should be stored at 15-30°C. The oral suspension should be stored below 25°C.
Información para el cliente
- La paciencia es clave: Los medicamentos conductuales como la paroxetina pueden tardar varias semanas (a menudo de 4 a 8 semanas) en mostrar efectos completos. No suspenda la medicación bruscamente a menos que su veterinario se lo indique.
- Administración: Puede administrarse con o sin comida. Si su mascota experimenta malestar estomacal, dársela con un pequeño premio o comida puede ayudar.
- Efectos secundarios: Esté atento a cambios en el apetito (es común que coman menos al principio), letargo o malestar gastrointestinal. En gatos, vigile de cerca si hay estreñimiento o cambios en los hábitos de uso del arenero.
- Seguridad: Mantenga el medicamento estrictamente fuera del alcance de niños y otras mascotas. Nunca administre a su mascota medicamentos para humanos sin la aprobación veterinaria, ya que las dosis difieren significativamente.
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.