Pentobarbital
Pentobarbital sodium
También conocido como: Nembutal · Dolethal · Euthanimal · Euthasal · Euthatal · Euthoxin · Lethobarb · Pentoject · aethaminalum · mebubarbital · mebumal · pentobarbitalum · pentobarbitone · Pentobarbital sodium
Revisado por el equipo veterinario de VetSheetActualizado 5 abr 2026Referencia veterinaria basada en la evidencia
Evidencia de dosis v13 auditada
Evidencia revisada no calculableEvidencia revisada no calculable (4)
Solo evidencia; no apta para cálculo automático
Crocodilians
TABLE 127.5. Agent: Pentobarbital. Dosage: 7.5–15 mg/kg ICe, or 8 mg/kg IM18,229. Species/Comments: Crocodilians.
Solo evidencia; no apta para cálculo automático
Snakes/induction, 30–60 min; duration, ≥ 2 hr; prolonged recovery (risk of occasional fatalities); venomous snakes require twice as much as nonvenomous snakes;18 avoid use in lizards
TABLE 127.5. Agent: Pentobarbital. Dosage: 15–30 mg/kg ICe229. Species/Comments: Snakes/induction, 30–60 min; duration, ≥ 2 hr; prolonged recovery (risk of occasional fatalities); venomous snakes require twice as much as nonvenomous snakes;18 avoid use in lizards.
Solo evidencia; no apta para cálculo automático
Chelonians
TABLE 127.5. Agent: Pentobarbital. Dosage: 10–18 mg/kg ICe229. Species/Comments: Chelonians.
Solo evidencia; no apta para cálculo automático
Rarely used as an anesthetic agent in reptiles
TABLE 127.5. Agent: Pentobarbital. Dosage: —. Species/Comments: Rarely used as an anesthetic agent in reptiles.
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
El pentobarbital es un oxibarbitúrico de acción corta utilizado principalmente en medicina veterinaria para la anestesia general, la contención química y el manejo del status epilepticus refractario.
Aunque históricamente fue popular como anestésico general, su uso ha sido desplazado en gran medida por agentes más seguros y titulables (como el propofol o la alfaxalona) debido a su estrecho índice terapéutico y sus profundos efectos depresores cardiopulmonares.
Perlas clínicas:
- Status Epilepticus: El pentobarbital se utiliza a menudo para inducir un "coma barbitúrico" en pacientes con convulsiones refractarias. Sin embargo, es un anestésico general con propiedades anticonvulsivas reales insignificantes a dosis estándar; detiene las manifestaciones físicas de las convulsiones, pero puede no detener la actividad eléctrica convulsiva subyacente en el cerebro.
- Soporte ventilatorio: Los pacientes tratados con pentobarbital para convulsiones graves generalmente requieren ventilación mecánica y monitorización en cuidados intensivos debido a la profunda depresión respiratoria.
- Eutanasia: A dosis significativamente más altas, el pentobarbital es el ingrediente activo principal en la mayoría de las soluciones veterinarias para la eutanasia (nota: la dosificación para eutanasia generalmente se cubre en monografías de combinación separadas).
- Inducción enzimática: El uso crónico induce fuertemente las enzimas hepáticas del citocromo P450, acelerando el metabolismo de muchos medicamentos concurrentes.
Mecanismo de acción
Pentobarbital exerts its profound central nervous system (CNS) depressant effects by interacting with the inhibitory neurotransmitter system.
- GABA_A Receptor Modulation: Binds to the barbiturate site on the GABA_A receptor → increases the duration of chloride channel opening → enhances chloride influx → hyperpolarization of the postsynaptic neuronal membrane.
- Glutamate Inhibition: At higher anesthetic doses, it also depresses the actions of the excitatory neurotransmitter glutamate via AMPA receptors.
- Result: Dose-dependent CNS depression ranging from mild sedation to general anesthesia, coma, and fatal respiratory depression.
Seguridad y advertencias
Contraindicaciones
- Severe hepatic impairment
- Severe respiratory depression or airway obstruction
- Porphyria
- Hypovolemia or severe cardiovascular instability (relative contraindication)
- Intramuscular (IM) administration (painful and slow to act)
- Use of euthanasia-specific solutions for seizure control or anesthesia
Efectos adversos
- Profound respiratory depression (apnea)
- Depression of myocardial metabolism
- Vasodilation and decreased venous return
- Hypotension and decreased cardiac perfusion
- Poikilothermia (hypothermia)
- Decreased urinary output
- Seizure-like movements or excitement during recovery from anesthesia
- Excitement and injury during induction/recovery in large animals (especially horses)
- Narcotic excitement (if not premedicated)
- Agonal gasping (reflexive, not a sign of pain)
- Muscle twitching
- Vocalization (rare, usually associated with excitement phase)
Precauciones
Cardiopulmonary Depression: Pentobarbital causes dose-dependent respiratory and cardiovascular depression. Patients in a 'barbiturate coma' commonly require mechanical ventilation and intensive care support (e.g., saline infusion and dopamine to manage hypotension).
Individual Variation: There is tremendous individual variation in response when used at standard safe doses. Always titrate to effect.
Laboratory Interference: Barbiturates may cause increased retention of bromosulfophthalein (BSP) and give falsely elevated results. Do not administer within 24 hours before BSP retention tests.
- Equine Use: Generally not considered an ideal agent for adult horses due to the possible development of excitement and injury when the animal is 'knocked down'.
- Tissue Irritation: Highly alkaline (pH 9-10.5); perivascular injection can cause severe tissue necrosis.
Interacciones farmacológicas
Decreased effect by lowering serum concentration (due to hepatic enzyme induction)
Decreased effect by lowering serum concentration
Decreased effect by lowering serum concentration
Decreased effect by lowering serum concentration
Decreased effect by lowering serum concentration
Decreased effect by lowering serum concentration
Decreased effect by lowering serum concentration
Decreased effect (may persist for weeks after barbiturate is discontinued)
Decreased effect by lowering serum concentration
Decreased effect by lowering serum concentration
Decreased effect by lowering serum concentration
Decreased effect by lowering serum concentration
Decreased effect by lowering serum concentration
Decreased effect by lowering serum concentration
Decreased effect by lowering serum concentration
Decreased effect by lowering serum concentration
Decreased effect by lowering serum concentration
Decreased effect by lowering serum concentration
Decreased effect by lowering serum concentration
Increase the CNS depressant effect of pentobarbital
Increase the CNS depressant effect of pentobarbital
Monitorización
- Levels of consciousness and/or seizure control
- Respiratory rate, rhythm, and depth (capnography and pulse oximetry highly recommended)
- Cardiac signs (heart rate, blood pressure, ECG)
- Body temperature (monitor for poikilothermia)
- Routine blood counts and liver function tests (if used chronically)
- Absence of heartbeat (auscultation)
- Absence of respiration
- Loss of corneal reflex
- Pupillary dilation
Farmacocinética
Vida media
Absorción
Rapidly absorbed following oral or intraperitoneal administration.
Distribución
Highly lipid soluble; rapidly crosses the blood-brain barrier to exert CNS effects. It subsequently redistributes from the brain to highly perfused tissues, and eventually to muscle and fat, which terminates its initial anesthetic effect.
Metabolismo
Extensively metabolized in the liver via cytochrome P450 enzymes. Chronic administration induces these enzymes, accelerating its own metabolism and that of other drugs.
Eliminación
Metabolites are primarily excreted by the kidneys.
Sobredosis
Overdose of pentobarbital leads to profound central nervous system depression, progressing rapidly to coma, severe respiratory depression (apnea), cardiovascular collapse, and death.
- Treatment: There is no specific reversal agent for barbiturates. Treatment is entirely supportive.
- Interventions: Immediate intubation and mechanical ventilation are required. Intravenous fluids and vasopressors (e.g., dopamine) should be administered to support blood pressure and cardiac output. Maintain body temperature to prevent severe hypothermia.
Productos disponibles
Formulaciones
- Injection (50 mg/mL)
- Suppositories
- Injectable: 200 mg/ml non-sterile aqueous solution
- Injectable: 400 mg/ml non-sterile aqueous solution
- Injectable: 500 mg/ml non-sterile aqueous solution
Veterinario
- Dolethal 200 mg/ml solution for injection
- Euthanimal 200 mg/ml / 400 mg/ml solution for injection
- Euthasal 400 mg/ml solution for injection
- Euthatal 200 mg/ml solution for injection
- Euthoxin 500 mg/ml solution for injection
- Lethobarb 200 mg/ml solution for injection
- Pentoject 200 mg/ml solution for injection
Etiquetado para humanos
- Pentobarbital Sodium Injection: 50 mg/mL in 2 mL Tubex; generic; (WyethAyerst); (Rx, C-II)
Estado regulador
Carcasses must not enter the food chain.
POM-V CD SCHEDULE 3. Safe custody requirements apply.
Sin datos reguladores para: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
The injectable product should be stored at room temperature; suppositories should be kept refrigerated. The aqueous solution is not very stable and should not be used if it contains a precipitate. Because precipitates may occur, pentobarbital sodium should not be added to acidic solutions.
Información para el cliente
Este medicamento es un sedante y anestésico potente.
- Uso hospitalario: Se utiliza casi exclusivamente en un entorno hospitalario veterinario bajo estrecha supervisión profesional, a menudo en una unidad de cuidados intensivos.
- Uso en el hogar: Si se dispensan formas de dosificación oral para uso en el hogar, es fundamental seguir estrictamente las instrucciones de dosificación del veterinario. Las sobredosis pueden ser fatales.
- Seguridad: Mantenga este medicamento en un recipiente seguro y a prueba de niños, completamente fuera del alcance de niños y otras mascotas. Es una sustancia estrictamente controlada.
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.