Metoprolol
Metoprolol tartrate, Metoprolol succinate
También conocido como: Lopressor · Toprol XL · CGP-2175E · H-93/26
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 |
|---|---|---|---|---|---|
| For rate control in chronic atrial fibrillation | 0.25-1 mg/kg PO q1224h. | PO | q1224h | — | 🌎 NA |
| For CHF (early/mild or well-controlled) | 0.2 mg/kg PO twice daily, with slow titration upwards every 2-3 weeks up to 0.4-6.6 mg/kg PO three times a day. | PO | BID to TID | — | 🌎 NA |
| To decrease the incidence of atrial fibrillation and flutter in dogs undergoing valve surgery | 0.4-1 mg/kg PO q24h | PO | q24h | — | 🌎 NA |
- For rate control in chronic atrial fibrillation: Note: 'q1224h' is transcribed exactly as it appears in the source text, likely a typo for q12-24h.
- For CHF (early/mild or well-controlled): Many dogs will not tolerate this upward titration.
- To decrease the incidence of atrial fibrillation and flutter in dogs undergoing valve surgery: Using sustained release metoprolol (ToprolXR) administered before and as soon as feasible after surgery.
Gatos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| As an oral beta blocker | 2-15 mg (total dose) PO q8h | PO | q8h | — | 🌎 NA |
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
El metoprolol es un bloqueador de los receptores adrenérgicos cardioselectivo (específico para beta1) ampliamente utilizado en medicina veterinaria para el manejo de diversas afecciones cardiovasculares.
Las aplicaciones clínicas clave incluyen:
- Manejo de taquiarritmias supraventriculares y contracciones ventriculares prematuras (PVCs/VPCs).
- Tratamiento de la hipertensión sistémica.
- Manejo de la miocardiopatía hipertrófica (MCH) en gatos, donde ayuda a reducir la obstrucción dinámica del tracto de salida del ventrículo izquierdo y mejora el tiempo de llenado diastólico.
Debido a su relativa beta1-selectividad, el metoprolol se considera generalmente más seguro que los betabloqueantes no selectivos (como el propranolol) en pacientes con enfermedad broncoconstrictora concurrente (p. ej., asma felina), aunque se debe tener precaución a dosis más altas donde la selectividad puede perderse.
Mecanismo de acción
Metoprolol competitively blocks beta1-adrenergic receptors located primarily in the myocardium.
Mechanism Pathway: Blockade of beta1-receptors → decreased activation of adenylyl cyclase → reduced intracellular cAMP → decreased intracellular calcium influx.
This results in:
- Negative chronotropy: Decreased sinus heart rate.
- Negative dromotropy: Slowed atrioventricular (AV) conduction.
- Negative inotropy: Decreased myocardial contractility and cardiac output.
- Decreased myocardial oxygen demand and reduced blood pressure.
Clinical Pearl: Metoprolol lacks intrinsic sympathomimetic activity (ISA) and membrane-stabilizing activity. At higher dosages, its cardioselectivity diminishes, leading to beta2-receptor blockade in bronchial smooth muscle → potential bronchoconstriction.
Seguridad y advertencias
Contraindicaciones
- Overt or unstable heart failure
- Hypersensitivity to beta-blockers
- Greater than first-degree heart block
- Sinus bradycardia
Efectos adversos
- Bradycardia
- Lethargy and depression
- Impaired AV conduction
- Congestive heart failure (CHF) or worsening of heart failure
- Hypotension
- Hypoglycemia
- Bronchoconstriction (at high doses)
- Syncope
- Diarrhea
Precauciones
Withdrawal Warning: Do not abruptly discontinue metoprolol therapy in chronic users. Abrupt cessation can lead to rebound tachycardia and exacerbation of clinical signs; taper the dose gradually.
- Respiratory Disease: Use with caution in patients with bronchospastic lung disease, even though it is relatively beta1-selective.
- Hepatic Impairment: Use cautiously in patients with significant hepatic insufficiency due to extensive hepatic metabolism.
- Endocrine: Can mask clinical signs of hypoglycemia and thyrotoxicosis. Use cautiously in labile diabetic patients as it can cause hypoglycemia or hyperglycemia.
- Cardiac: Use cautiously in patients with sinus node dysfunction or compensated CHF.
Interacciones farmacológicas
Increased risk for heart failure and hypotension due to additive myocardial depressant effects.
Concurrent use should be done with caution; additive negative inotropic and chronotropic effects, particularly in patients with preexisting cardiomyopathy or CHF.
May increase negative effects on SA or AV node conduction.
May increase the hypotensive effect of metoprolol.
May increase the risks for pulmonary hypertension in uremic patients.
May increase metoprolol plasma concentrations.
Potential for additive effects including hypotension and bradycardia.
May increase metoprolol plasma concentrations.
May have their actions blocked by metoprolol, and they may in turn reduce the efficacy of the beta-blocker.
Monitorización
- Cardiac function
- Pulse rate
- ECG (if necessary)
- Blood pressure (if indicated)
- Signs of toxicity (bradycardia, hypotension, lethargy)
Farmacocinética
Vida media
Absorción
Rapidly and nearly completely absorbed from the GI tract, but undergoes a high first-pass effect (50%), reducing systemic bioavailability.
Distribución
Very low protein binding (5-15%). Distributes well into most tissues. Crosses the blood-brain barrier (CSF levels are ~78% of serum levels). Crosses the placenta, and milk concentrations are 3-4 times higher than plasma.
Metabolismo
Primarily biotransformed in the liver.
Eliminación
Unchanged drug and metabolites are principally excreted in the urine.
Sobredosis
Overdosage primarily results in extensions of the drug's pharmacologic effects: hypotension, bradycardia, bronchospasm, cardiac failure, and potentially hypoglycemia.
Treatment:
- Decontamination: If recent oral ingestion, consider emptying the gut and administering activated charcoal. Caution: Inducing emesis can be risky as coma and seizures may develop rapidly.
- Monitoring: Continuous ECG, blood pressure, blood glucose, and potassium.
- Cardiovascular Support: Treat symptomatically. Use IV fluids and pressor agents for hypotension.
- Bradycardia: Treat with atropine. If atropine fails, isoproterenol may be given cautiously. A transvenous pacemaker may be necessary.
- Cardiac Failure: May be treated with digitalis glycosides, diuretics, and oxygen.
- Antidote: Glucagon (5-10 mg IV - human dose) may increase heart rate and blood pressure and reduce the cardiodepressant effects of metoprolol.
Productos disponibles
Formulaciones
- Oral tablets (tartrate)
- Extended-release oral tablets (succinate)
- Injection (tartrate)
- Compounded oral suspension
Etiquetado para humanos
- Metoprolol Tartrate Oral Tablets: 25 mg, 50 mg & 100 mg (Lopressor, generic)
- Metoprolol Succinate Extended-Release Tablets: 25 mg, 50 mg, 100 mg & 200 mg (Toprol XL, generic)
- Metoprolol Tartrate Injection: 1 mg/mL in 5 mL amps and Carpuject sterile cartridge units (Lopressor, generic)
Estado regulador
Sin datos reguladores para: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
Store all products protected from light. Store tablets in tight, light-resistant containers at room temperature. Avoid freezing the injection. Compounded oral suspensions (10 mg/mL) retain >95% potency for 60 days when stored at 4°C or 25°C and protected from light.
Información para el cliente
Información importante para los propietarios de mascotas
- La constancia es clave: Para que sea eficaz, su mascota debe recibir todas las dosis exactamente según lo prescrito por su veterinario.
- No suspenda el tratamiento bruscamente: Nunca deje de administrar este medicamento repentinamente sin consultar a su veterinario, ya que puede causar un aumento peligroso en la frecuencia cardíaca o empeorar las afecciones cardíacas.
- Qué observar: Comuníquese con su veterinario de inmediato si su mascota se muestra inusualmente letárgica, se cansa fácilmente durante el ejercicio, desarrolla dificultad para respirar o tos, o muestra un cambio repentino en su comportamiento o actitud.
- Mascotas diabéticas: Si su mascota es diabética, controle sus niveles de azúcar en sangre de cerca, ya que este medicamento puede ocultar los signos normales de niveles bajos de azúcar en sangre (hipoglucemia).
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.