Amitriptilina
Amitriptyline
Amitriptyline hydrochloride
También conocido como: Elavil · Lentizol · Tryptanol · Amitriptylini hydrochloridum · Amitriptylinum · Amitriptyline hydrochloride
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 |
|---|---|---|---|---|---|
| Adjunctive treatment of pruritus | 1-2 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
| Acral pruritic dermatitis | 2.2 mg/kg PO twice daily | PO | q12h | 2-4 week trial recommended | 🌎 NA |
| Separation anxiety or generalized anxiety | 1-2 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
| Behavior disorders amenable to tricyclics | 1-4 mg/kg PO q12h. Begin at 1-2 mg/kg PO q12h for 2 weeks, increase by 1 mg/kg up to maximum dosage (4 mg/kg) as necessary. If no clinical response, decrease by 1 mg/kg PO q12h for 2 weeks until at initial dosage. | PO | q12h | — | 🌎 NA |
| Behavior disorders amenable to tricyclics | 2.2-4.4 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
| Behavior disorders amenable to tricyclics | 0.25-1.5 mg/kg PO every 12-24h | PO | q12-24h | — | 🌎 NA |
| Neuropathic pain | 1-2 mg/kg PO q12-24h | PO | q12-24h | — | 🌎 NA |
| Adjunctive treatment of pain associated with appendicular osteosarcoma | 1-2 mg/kg PO q12-24h | PO | q12-24h | — | 🌎 NA |
| Management of chronic anxiety, compulsive disorders, and separation anxiety | 1-2 mg/kg | PO | q12-24h | — | 🌍 EU |
- Acral pruritic dermatitis: Only occasionally effective.
- Separation anxiety or generalized anxiety: Use with behavior modification.
- Management of chronic anxiety, compulsive disorders, and separation anxiety: Clomipramine is an authorized preparation for dogs and is claimed to have better anticompulsive properties.
Gatos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Adjunctive treatment of behavior disorders amenable to tricyclics | 5-10 mg per cat PO once daily | PO | q24h | — | 🌎 NA |
| Adjunctive treatment of behavior disorders amenable to tricyclics | 0.5-2 mg/kg PO q12-24h; start at 0.5 mg/kg PO q12h | PO | q12-24h | — | 🌎 NA |
| Adjunctive treatment of behavior disorders amenable to tricyclics | 0.5-1 mg/kg PO q12-24h | PO | q12-24h | — | 🌎 NA |
| Adjunctive treatment of behavior disorders amenable to tricyclics | 0.5-1 mg/kg PO q12-24h. Allow 3-4 weeks for initial trial. | PO | q12-24h | 3-4 weeks initial trial | 🌎 NA |
| Self-mutilation behaviors associated with anxiety | 5-10 mg per cat PO once to twice daily | PO | q12-24h | — | 🌎 NA |
| Self-mutilation behaviors associated with anxiety | 1-2 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
| Pruritus (after other more conventional therapies have failed) | 5-10 mg per cat PO once daily or 2.5-7.5 mg/cat once to twice daily. When discontinuing, taper dose over 1-3 weeks. | PO | q12-24h | — | 🌎 NA |
| Symptomatic therapy of idiopathic feline lower urinary tract disease (FLUTD) | 2.5-12.5 mg (total dose) PO once daily at night | PO | q24h | — | 🌎 NA |
| Symptomatic therapy of idiopathic feline lower urinary tract disease (FLUTD) | 5-10 mg (total dose) PO once daily at night; the drug is in popular use at present and further studies are needed | PO | q24h | — | 🌎 NA |
| Symptomatic therapy of idiopathic feline lower urinary tract disease (FLUTD) | 2.5-12.5 mg (total dose) PO at the time the owner retires for the night. Dosage is adjusted to produce a barely perceptible calming effect on the cat. If no improvement is seen within 2 months, the medication may be gradually tapered and then stopped. | PO | q24h | 2 months trial | 🌎 NA |
| Neuropathic pain | 2.5-12.5 mg/cat PO once daily | PO | q24h | — | 🌎 NA |
| Neuropathic pain | 0.5-2 mg/kg PO once daily; may be a useful addition to NSAIDs for chronic pain. | PO | q24h | — | 🌎 NA |
| Management of psychogenic alopecia, hypervocalization, and idiopathic cystitis | 0.5-1 mg/kg | PO | q24h | — | 🌍 EU |
- Self-mutilation behaviors associated with anxiety: With behavior modification.
- Pruritus (after other more conventional therapies have failed): Taper dose over 1-3 weeks when discontinuing.
- Symptomatic therapy of idiopathic feline lower urinary tract disease (FLUTD): Reserved for cases with severe, recurrent signs.
- Management of psychogenic alopecia, hypervocalization, and idiopathic cystitis: Very bitter taste; can cause ptyalism.
Aves
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Adjunctive treatment of feather plucking | 1-2 mg/kg PO q12-24 hours. Anecdotal reports indicate some usefulness. Barring side-effects, may be worth a more prolonged course of therapy to determine efficacy. | PO | q12-24h | Prolonged course | 🌎 NA |
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
La amitriptilina es un antidepresivo tricíclico (ATC) de primera generación. Aunque fármacos más nuevos como la clomipramina o los ISRS (p. ej., fluoxetina) la han sustituido en gran medida para los trastornos conductuales primarios en perros (como la ansiedad por separación), la amitriptilina sigue siendo un fármaco muy versátil en medicina veterinaria.
Perla clínica: Su actividad multimodal sobre los receptores la hace particularmente útil para el tratamiento coadyuvante del dolor neuropático, el prurito (debido a sus potentes efectos antihistamínicos) y la enfermedad del tracto urinario inferior felino (FLUTD/FIC). También se utiliza ocasionalmente en medicina aviar para controlar conductas de picaje de plumas.
Mecanismo de acción
Amitriptyline and its active metabolite, nortriptyline, exhibit a complex pharmacologic profile, affecting multiple receptor systems:
- Serotonin (SERT) & Norepinephrine (NET) Reuptake Inhibition: Blocks the amine pump → increases synaptic levels of 5-HT and NE → mood stabilization and descending pain pathway modulation.
- H1-Receptor Antagonism: Potent antihistamine effect → stabilizes mast cells and provides antipruritic action.
- M1-Muscarinic (Anticholinergic) Antagonism: Causes smooth muscle relaxation (useful in FLUTD) but also leads to side effects like dry mouth and urine retention.
- Alpha-1 Adrenergic Antagonism: Can cause mild vasodilation and sedation.
- NMDA Receptor & Sodium Channel Blockade: Contributes to its efficacy in treating chronic, neuropathic pain.
Seguridad y advertencias
Contraindicaciones
- Prior sensitivity to any tricyclic antidepressant
- Concomitant use with monoamine oxidase inhibitors (MAOIs)
Efectos adversos
- Sedation
- Constipation
- Urinary retention
- Hyperexcitability (dogs)
- Seizures (rare)
- Cardiac dysrhythmias
- Bone marrow suppression
- Vomiting
- Diarrhea
- Hypersalivation (cats)
- Anorexia (cats)
- Thrombocytopenia
- Neutropenia
- Unkempt hair coat (cats)
- Ataxia
- Disorientation
Precauciones
Use with extreme caution in patients with seizure disorders as tricyclic agents may reduce seizure thresholds. Use with caution in patients with thyroid disorders, hepatic disorders, keratoconjunctivitis sicca (KCS), glaucoma, cardiac rhythm disorders, diabetes, or adrenal tumors. FDA Pregnancy Category D (restrict use to pregnant animals only when benefits clearly outweigh risks).
Interacciones farmacológicas
Increased effects; hyperthermia and ileus possible
May inhibit tricyclic antidepressant metabolism and increase the risk of toxicity
May have additive effects on QTc interval; possible serious arrhythmias may result
Potential life-threatening serotonin syndrome; use together not recommended
Increased sedative effects
Possible increased amitriptyline levels
Increased risk for QTc interval prolongation and tricyclic adverse effects
Potential increased amitriptyline levels, increased risk for serotonin syndrome; enhanced monitoring suggested if used together
May increase the risk of cardiac effects (arrhythmias, hypertension, hyperpyrexia)
Increased risk for arrhythmias; monitor closely
Risk of fatal serotonin syndrome. Requires a minimum 2-week washout period.
Metabolized by CYP2D6; may alter amitriptyline metabolism.
Concurrent use increases the risk of serotonin syndrome.
Concurrent use increases the risk of serotonin syndrome.
Increased risk of serotonin syndrome and seizure threshold reduction.
Monitorización
- Clinical efficacy (behavior, pain, or pruritus improvement)
- Adverse effects
- Baseline cardiac evaluation (ECG) prior to therapy
- Baseline CBC and serum chemistry panel prior to therapy
- Liver enzymes in cats (prior to therapy, 1 month after initial therapy, and yearly thereafter)
Farmacocinética
Vida media
Absorción
Rapidly absorbed from both the GI tract and parenteral injection sites. Transdermal (PLO-gel based) absorption in cats is poor. Peak levels occur in 1-2 hours after oral administration in cats and within 2-12 hours in other species.
Distribución
Highly bound to plasma proteins. Enters the CNS and enters maternal milk in levels at or greater than those found in maternal serum.
Metabolismo
Metabolized in the liver to several metabolites, including the active metabolite nortriptyline.
Eliminación
Eliminated primarily via hepatic metabolism.
Sobredosis
Overdosage with tricyclics can be life-threatening (arrhythmias, cardiorespiratory collapse). Because toxicities and therapies are complicated, it is recommended to contact an animal poison control center immediately in any potential overdose situation.
- Dogs: Common findings include lethargy and tachycardia.
- Cats: Common findings include vocalization, ataxia, mydriasis (dilated pupils), tachycardia, disorientation, lethargy, and agitation.
Productos disponibles
Formulaciones
- Tablets
- Injection
Etiquetado para humanos
- Amitriptyline HCl Tablets: 10 mg, 25 mg, 50 mg, 75 mg, 100 mg, & 150 mg
Estado regulador
POM (Prescription Only Medicine). Clomipramine is the authorized TCA for dogs in the EU.
POM-V. Prescribed under the cascade as human generic preparations.
Sin datos reguladores para: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
Tablets should be stored at room temperature. The injection should be kept from freezing and protected from light.
Información para el cliente
La paciencia es clave: Los cambios de comportamiento no ocurrirán de la noche a la mañana. Por lo general, se requieren varias semanas de administración diaria constante para observar el efecto completo.
- No suspender bruscamente: Si se interrumpe la medicación, la dosis debe reducirse gradualmente bajo supervisión veterinaria para evitar signos de abstinencia.
- Efectos secundarios: Su mascota puede parecer somnolienta o tener la boca seca (puede notar que se lame los labios con más frecuencia). Puede ocurrir estreñimiento o dificultad para orinar; informe a su veterinario si observa estos signos.
- Advertencia de toxicidad: Manténgase estrictamente fuera del alcance de los niños y otras mascotas en envases a prueba de niños. Una sobredosis puede ser fatal.
- Administración: Las pastillas pueden ser amargas. Se recomienda esconderlas en un premio muy apetecible o en un bolsillo para pastillas (pill pocket).
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.