Mexiletina
Mexiletine
Mexiletine hydrochloride
También conocido como: Mexilen · Mexitilen · Myovek · Ritalmex · Ko-1173 · mexiletini hydrochloridum
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 |
|---|---|---|---|---|---|
| Treating or assisting in treatment of ventricular arrhythmias | 5-8 mg/kg | PO | q8h | — | 🌎 NA |
| Treating or assisting in treatment of ventricular arrhythmias | 4-10 mg/kg | PO | q8h | — | 🌎 NA |
| Ventricular arrhythmias in Boxers | 5-7.5 mg/kg | PO | three times daily | — | 🌎 NA |
| Treating or assisting in treatment of ventricular arrhythmias | 4-8 mg/kg | PO | q8h | — | 🌎 NA |
| Familial arrhythmic cardiomyopathy of Boxers (ARVC) | 5-8 mg/kg | PO | q8h | — | 🌎 NA |
| Treating or assisting in treatment of ventricular arrhythmias | 5-6 mg/kg | PO | q8h | — | 🌎 NA |
| Myotonia congenita or myokymia | 8.3 mg/kg | PO | q8h | — | 🌎 NA |
- Ventricular arrhythmias in Boxers: Given with sotalol at 1.5-3 mg/kg twice daily; was successful in 7/8 dogs treated in study.
- Treating or assisting in treatment of ventricular arrhythmias: Combined with atenolol (0.5 mg/kg PO q12-24h).
- Familial arrhythmic cardiomyopathy of Boxers (ARVC): Given with atenolol at 12.5 mg (total dose) q12h.
- Treating or assisting in treatment of ventricular arrhythmias: Always give with food to avoid nausea.
- Myotonia congenita or myokymia: Most studied in Chow Chows, miniature schnauzers, and Jack Russell terriers.
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
La mexiletina es un agente antiarrítmico de Clase IB oral que comparte un perfil electrofisiológico muy similar al de la lidocaína. Debido a que la lidocaína experimenta un metabolismo de primer paso extenso y no puede administrarse por vía oral, la mexiletina a menudo se considera la "lidocaína oral" para el manejo crónico de las arritmias.
En medicina veterinaria, se utiliza principalmente para tratar arritmias ventriculares (como complejos ventriculares prematuros [CVP] y taquicardia ventricular) en perros. Es particularmente notable su uso en Boxers con miocardiopatía arritmogénica del ventrículo derecho (ARVC) y Doberman Pinschers con miocardiopatía dilatada (DCM). Frecuentemente se combina con betabloqueantes (como el atenolol) o sotalol para obtener efectos sinérgicos.
Además, la mexiletina se utiliza para tratar ciertas miopatías hereditarias raras, incluyendo la miotonía congénita (observada en Chow Chows y Schnauzers miniatura) y la mioquimia (observada en Jack Russell Terriers).
Mecanismo de acción
Mexiletine is a Class IB antiarrhythmic.
- Mechanism: It binds to and inhibits the inward fast sodium channels (Na+) in the myocardial cell membrane.
- Electrophysiologic Effects: By blocking these channels, it reduces the rate of rise of the action potential (Phase 0). In Purkinje fibers, it decreases automaticity, shortens the action potential duration, and decreases the effective refractory period.
- Selectivity: Like lidocaine, it is highly selective for diseased, ischemic, or rapidly firing myocardial tissue, making it effective at suppressing ventricular ectopic pacemakers without significantly depressing normal sinus node function or conduction (unless pre-existing abnormalities exist).
Seguridad y advertencias
Contraindicaciones
- Pre-existing 2nd or 3rd degree AV block (without a pacemaker)
- Cardiogenic shock
- Known hypersensitivity to mexiletine
Efectos adversos
- Vomiting (very common)
- Nausea
- Trembling/Tremors
- Unsteadiness/Ataxia
- Dizziness
- Depression/Lethargy
- Shortness of breath
- Proarrhythmia (PVCs)
- Chest pain
- Seizures (rare)
- Agranulocytosis (rare)
- Thrombocytopenia (rare)
Precauciones
Use with extreme caution in patients with severe congestive heart failure, acute myocardial infarction, hepatic function impairment, hypotension, intraventricular conduction abnormalities, sinus node function impairment, or a pre-existing seizure disorder.
Clinical Note: Mexiletine is secreted into maternal milk; use of a milk replacer is recommended if the nursing mother is receiving the drug. FDA Pregnancy Category C.
Interacciones farmacológicas
May slow the absorption of mexiletine.
May reduce the rate of oral absorption.
May increase or decrease mexiletine blood levels.
May accelerate the metabolism of mexiletine.
May cause additive adverse effects (especially CNS toxicity).
May accelerate the absorption of mexiletine.
May slow the absorption of mexiletine.
May accelerate the metabolism of mexiletine.
May accelerate the metabolism of mexiletine.
May accelerate the metabolism of mexiletine.
May accelerate the metabolism of mexiletine.
Mexiletine may reduce the metabolism of theophylline, potentially leading to theophylline toxicity.
May accelerate the renal excretion of mexiletine.
May reduce the urinary excretion of mexiletine.
Monitorización
- Electrocardiogram (ECG) to assess antiarrhythmic efficacy and monitor for proarrhythmia
- Clinical signs of adverse effects (especially GI and CNS signs)
- Plasma concentrations (Therapeutic range in humans: 0.5-2 mcg/mL; note that toxicity may be noted even at therapeutic levels)
- Liver enzymes (AST may transiently increase in a small percentage of patients)
Farmacocinética
Absorción
Relatively well absorbed from the gastrointestinal tract with a low first-pass effect.
Distribución
Moderately bound to plasma proteins (60-75% in humans).
Metabolismo
Metabolized in the liver to inactive metabolites.
Eliminación
Excreted via the kidneys. Renal excretion rate is dependent on urinary pH (acidification accelerates excretion, alkalinization reduces it).
Sobredosis
Toxicity associated with overdosage can be significant and life-threatening.
- Clinical Signs: In human case reports, CNS signs (tremors, seizures, depression) always preceded cardiovascular signs (hypotension, bradycardia, heart block).
- Treatment:
- Perform GI tract emptying protocols (emesis/gastric lavage) if indicated and safe.
- Administer supportive therapy.
- Acidification of the urine may be considered to enhance urinary excretion.
- Atropine may be useful if severe hypotension or bradycardia occurs.
Productos disponibles
Formulaciones
- Oral Capsules: 150 mg, 200 mg, 250 mg
Etiquetado para humanos
- Mexiletine Oral Capsules: 150 mg, 200 mg & 250 mg (generic)
Estado regulador
Sin datos reguladores para: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
Mexiletine capsules should be stored in tight containers at room temperature.
Información para el cliente
- Administrar siempre con comida: Este medicamento frecuentemente causa malestar estomacal, náuseas y vómitos. Administrarlo con una comida completa reduce significativamente este riesgo.
- Adherencia estricta: No omita dosis ni suspenda el medicamento sin consultar a su veterinario. Las arritmias ventriculares pueden poner en peligro la vida y pueden reaparecer rápidamente si se interrumpe el fármaco.
- Monitoreo de efectos secundarios: Comuníquese con su veterinario de inmediato si su mascota presenta vómitos persistentes, temblores, inestabilidad, mareos, letargo extremo o dificultad para respirar.
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.