Cloruro de Pralidoxima
Pralidoxime Chloride
2-Formyl-1-methylpyridinium chloride oxime
También conocido como: Protopam Chloride · 2-Formyl-1-methylpyridinium chloride oxime · 2-PAM chloride · 2-PAMCl · 2-pyridine aldoxime methochloride
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 |
|---|---|---|---|---|---|
| Organophosphate poisoning | 20 mg/kg | IM or slow IV | 2-3 times a day | — | 🌎 NA |
| Organophosphate poisoning | 10-15 mg/kg | IM or SC | q8-12h | 36 hour minimum | 🌎 NA |
| Organophosphate poisoning | 50 mg/kg | slow IV | May repeat in one hour if severe | Recovery should occur gradually over 48 hours | 🌎 NA |
| Organophosphate poisoning | 50 mg/kg | IV | Repeat in one hour if signs persist, then q8h | 24-48 hours | 🌎 NA |
- Organophosphate poisoning: Works best when combined with atropine. Initial dose IM or slow IV; subsequent doses IM or SC.
- Organophosphate poisoning: Give atropine first (0.1 mg/kg IV, then 0.3 mg/kg IM). Dilute pralidoxime in 10% glucose. For small dogs, may administer IM or IP. Reduce dose in renal failure.
- Organophosphate poisoning: Give slowly or with fluids over a 30-minute period. If clinical signs intensify (e.g., respiratory depression), reduce dose and give as repeated one-hour infusions every 4-8 hours in combination with atropine.
Gatos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Organophosphate poisoning | 20 mg/kg | IM or slow IV | 2-3 times a day | — | 🌎 NA |
| Organophosphate poisoning | 10-15 mg/kg | IM or SC | q8-12h | 36 hour minimum | 🌎 NA |
| Organophosphate poisoning | 50 mg/kg | slow IV | May repeat in one hour if severe | Recovery should occur gradually over 48 hours | 🌎 NA |
| Organophosphate poisoning | 20 mg/kg | IV | Repeat in one hour if signs persist, then q8h | 24-48 hours | 🌎 NA |
| Organophosphate poisoning | 20 mg/kg | IM or IV | May repeat q6-8h | — | 🌎 NA |
- Organophosphate poisoning: Works best when combined with atropine. Initial dose IM or slow IV; subsequent doses IM or SC.
- Organophosphate poisoning: Give atropine first. Dilute in 10% glucose. May administer IM or IP. Reduce dose in renal failure.
- Organophosphate poisoning: Give slowly or with fluids over a 30-minute period.
- Organophosphate poisoning: Give within first 24 hours of exposure. Combine with atropine or give separately. Do not use in carbamate toxicity.
Aves
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Organophosphate poisoning | 10-20 mg/kg | Not specified | q8-12h | — | 🌎 NA |
| Organophosphate poisoning | 10-100 mg/kg | IM | q24-48h or repeat once in 6 hours | — | 🌎 NA |
- Organophosphate poisoning: Give with atropine (0.2-0.5 mg/kg IM q3-4h).
Caballos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Organophosphate poisoning | 20 mg/kg (may require up to 35 mg/kg) | IV | q4-6h | — | 🌎 NA |
Ganado
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Organophosphate poisoning | 30 mg/kg | IM | q8h | — | 🌎 NA |
| Organophosphate poisoning | 25-50 mg/kg | IV | Single dose, or maximum of 100 mg/kg/day as an IV drip | — | 🌎 NA |
- Organophosphate poisoning: FARAD recommends a 28-day meat and a 6-day milk withdrawal time.
- Organophosphate poisoning: Give as a 20% solution over 6 minutes.
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
La pralidoxima (a menudo denominada 2-PAM) es un antídoto específico utilizado principalmente en medicina veterinaria para tratar la toxicidad por organofosforados (OP). Los organofosforados se encuentran comúnmente en insecticidas antiguos, productos químicos agrícolas y algunos agentes nerviosos. Actúan uniéndose irreversiblemente a la acetilcolinesterasa (AChE) e inhibiéndola, lo que provoca una acumulación masiva de acetilcolina en las sinapsis nerviosas y las uniones neuromusculares.
La pralidoxima actúa como un reactivador de la colinesterasa, separando eficazmente la molécula de OP de la enzima antes de que el enlace se vuelva permanente (un proceso conocido como "envejecimiento").
Perla clínica: La pralidoxima casi siempre se utiliza junto con atropina. Mientras que la atropina bloquea los efectos muscarínicos del exceso de acetilcolina (signos SLUDDE: salivación, lagrimeo, micción, defecación, disnea, emesis), la pralidoxima es necesaria para aliviar los efectos nicotínicos, particularmente los temblores musculares profundos, la debilidad y la parálisis (incluidos los músculos respiratorios). Generalmente no se recomienda para la toxicidad por carbamatos, ya que los enlaces carbamato-AChE se revierten espontáneamente sin necesidad de un reactivador de tipo oxima.
Mecanismo de acción
Pralidoxime works by directly reactivating the acetylcholinesterase enzyme that has been inhibited by organophosphates.
- Organophosphates bind to the esteratic site of acetylcholinesterase (AChE) via phosphorylation, inactivating the enzyme.
- Accumulation of acetylcholine (ACh) occurs at muscarinic and nicotinic receptors → severe overstimulation.
- Pralidoxime possesses a high affinity for the AChE enzyme.
- Via nucleophilic attack, the oxime group of pralidoxime binds to the offending phosphoryl group of the organophosphate.
- The pralidoxime-organophosphate complex breaks away from the enzyme → AChE is reactivated and resumes breaking down ACh.
Important Mechanistic Note: If the phosphorylated enzyme undergoes a chemical change (loss of an alkyl group) before pralidoxime is administered, the bond becomes permanent. This is known as "aging". Therefore, pralidoxime is most effective when given within 24 hours of exposure, though some benefit may be seen up to 36-48 hours in massive exposures.
Seguridad y advertencias
Contraindicaciones
- Hypersensitivity to pralidoxime
- Carbamate poisoning (generally not recommended as inhibition is rapidly reversible)
Efectos adversos
- Tachycardia (especially with rapid IV injection)
- Muscle rigidity
- Transient neuromuscular blockade
- Laryngospasm
Precauciones
Use with caution in patients receiving anticholinesterase agents for the treatment of myasthenia gravis, as it may precipitate a myasthenic crisis. Use cautiously and at a reduced dosage rate in patients with renal impairment. Must generally be given within 24 hours of exposure to be effective. Rapid IV injection should be avoided to prevent tachycardia, muscle rigidity, and laryngospasm.
Interacciones farmacológicas
Anticholinesterases can potentiate the action of barbiturates; use with caution.
Use should be avoided in patients with organophosphate toxicity.
Use should be avoided in patients with organophosphate toxicity.
Use should be avoided in patients with organophosphate toxicity.
Use should be avoided in patients with organophosphate toxicity.
Use should be avoided in patients with organophosphate toxicity.
Monitorización
- Clinical signs associated with organophosphate poisoning (SLUDDE signs, muscle fasciculations, weakness)
- Heart rate and rhythm (especially during IV administration)
- Respiratory rate and effort
Farmacocinética
Absorción
Marginally absorbed after oral dosing; oral dosage forms are no longer available in the United States.
Distribución
Distributed primarily throughout the extracellular water. Because of its quaternary ammonium structure, it is historically not believed to enter the CNS in significant quantities, but recent studies and clinical responses have led some to question this belief.
Metabolismo
Thought to be metabolized by the liver.
Eliminación
Excreted as both metabolite(s) and unchanged drug in the urine.
Sobredosis
The acute LD50 of pralidoxime in dogs is 190 mg/kg. At high dosages, it causes signs associated with its own anticholinesterase activity.
Clinical signs of toxicity in dogs may be exhibited as:
- Muscle weakness
- Ataxia
- Vomiting
- Hyperventilation
- Seizures
- Respiratory arrest
- Death
Productos disponibles
Formulaciones
- Powder for injection
Etiquetado para humanos
- Pralidoxime Chloride Powder for Injection: 1 gram in 20 mL single-use vials (Protopam Chloride)
Estado regulador
Sin datos reguladores para: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
Unless otherwise instructed by the manufacturer, pralidoxime chloride powder for injection should be stored at room temperature. After reconstituting with sterile water for injection, the solution should be used within a few hours. Do not use sterile water with preservatives added.
Información para el cliente
- Tratamiento de emergencia: Este medicamento es un antídoto crítico y vital para tipos específicos de envenenamiento por pesticidas o agentes nerviosos (organofosforados).
- Requiere hospitalización: Su mascota deberá ser hospitalizada y monitoreada de cerca por profesionales veterinarios mientras recibe este medicamento.
- Sensible al tiempo: Este antídoto es más eficaz cuando se administra lo antes posible después de la exposición (idealmente dentro de las primeras 24 horas).
- Terapia combinada: Casi siempre se administra junto con otro antídoto llamado atropina para controlar completamente los síntomas graves del envenenamiento.
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.