Fisostigmina
Physostigmine
Physostigmine salicylate
También conocido como: Antilirium · Anticholium · Eserine salicylate · Physostigmine monosalicylate
Revisado por el equipo veterinario de VetSheetActualizado 5 abr 2026Referencia veterinaria basada en la evidencia
Evidencia posológica v13 auditada
Evidencia revisada no calculableEvidencia revisada no calculable (1)
Solo evidencia; no apta para cálculo automático
May ameliorate flaccid paralysis from ivermectin or levamisole toxicosis
TABLE 128.6. Agent: Physostigmine (ophthalmic drops). Dosage: 1 drop/50 g topically q1–2h to effect52. Species/Comments: May ameliorate flaccid paralysis from ivermectin or levamisole toxicosis.
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
La fisostigmina es un inhibidor de la colinesterasa reversible utilizado principalmente en medicina veterinaria como tratamiento coadyuvante para la toxicidad por ivermectina, como agente provocador para el diagnóstico de narcolepsia/cataplejía en perros y caballos, y como antídoto para la toxicidad anticolinérgica central.
Perlas clínicas:
- A diferencia de los inhibidores de la colinesterasa de amonio cuaternario (p. ej., neostigmina, piridostigmina), la fisostigmina es una amina terciaria.
- Esta diferencia estructural le permite atravesar fácilmente la barrera hematoencefálica (BHE), lo que la hace singularmente eficaz para tratar la toxicidad anticolinérgica central.
- Debido a que penetra en el SNC, conlleva un mayor riesgo de efectos tóxicos centrales (p. ej., convulsiones) en comparación con sus contrapartes cuaternarias.
- Debido a su estrecho índice terapéutico y al potencial de efectos adversos graves, su uso generalmente se reserva para la toxicidad del SNC que pone en peligro la vida.
Mecanismo de acción
Physostigmine reversibly inhibits the enzyme acetylcholinesterase → prevents the hydrolysis and destruction of acetylcholine (ACh) → increases the concentration of ACh at both muscarinic and nicotinic receptor sites.
Because it is a lipophilic tertiary amine, it crosses the blood-brain barrier and exerts its cholinergic effects both centrally and peripherally. This widespread cholinergic stimulation leads to miosis, bronchoconstriction, hypersalivation, and increased gastrointestinal motility.
Seguridad y advertencias
Contraindicaciones
- Prior hypersensitivity reactions to physostigmine or sulfites
- Bronchoconstrictive disease (asthma)
- Gangrene
- Diabetes mellitus
- Cardiovascular disease
- Mechanical obstruction of the GI or urinary tract
- Any vagotonic state
- Concurrent use of choline esters or depolarizing neuromuscular blocking agents
Efectos adversos
- Miosis
- Bronchial constriction
- Hypersalivation
- Muscle weakness
- Sweating (in species with sweat glands)
- Seizures
- Bradycardia
- Tachycardia
- Asystole
- Nausea
- Vomiting
- Diarrhea
- Depolarizing neuromuscular block
- Pulmonary edema
- Respiratory paralysis
Precauciones
WARNING: Toxic effects from this drug can be serious and life-threatening. Must be administered with direct patient supervision.
- Cholinergic Crisis Risk: Increased risk when used in the absence of anticholinergic toxicity or to treat tricyclic/tetracyclic antidepressant overdoses.
- Administration Rate: Rapid IV administration increases the potential for bradycardia, hypersalivation, or seizures. Must be given slowly.
- Antidote Availability: Atropine must be readily available when administering physostigmine.
- Neonatal Toxicity: The injection contains benzyl alcohol, which may be toxic to neonatal animals.
- Pregnancy: Weigh potential risks versus benefits. Teratogenic effects have been observed in mice.
Interacciones farmacológicas
May cause additive adverse cholinergic effects.
May cause additive adverse cholinergic effects.
High doses of physostigmine may cause muscle fasciculations or depolarization block, which may be additive to the effects of succinylcholine-like neuromuscular blockers.
Monitorización
- Direct patient supervision is required
- Blood pressure
- ECG/Heart rhythm (especially if heart rate is abnormal)
- Signs of cholinergic crisis (salivation, lacrimation, urination, defecation, dyspnea, emesis)
Farmacocinética
Absorción
Rapidly absorbed from the GI tract (though no oral dosage form is available), subcutaneous tissue, or mucous membranes. Peak effects occur within 5 minutes after IV administration and about 25 minutes after IM dosing.
Distribución
Readily crosses the blood-brain barrier into the CNS due to its tertiary amine structure.
Metabolismo
The majority of the administered drug is rapidly destroyed via hydrolysis by cholinesterases.
Eliminación
Very small amounts can be eliminated unchanged into the urine. Duration of pharmacologic effects ranges from 30 minutes to 5 hours (average duration is 30-60 minutes).
Sobredosis
Overdoses or acute toxicity can be life-threatening and may result in a severe cholinergic crisis (seizures, bradycardia, asystole, respiratory paralysis).
- Supportive Care: Because of the short duration of effect, supportive care (including mechanical ventilation and repeated bronchial aspiration) may be sufficient in some cases.
- Antidote (Muscarinic): Administration of IV atropine is the primary treatment for cholinergic toxicity. Re-administration may be required.
- Antidote (Nicotinic): Pralidoxime (2-PAM) may be useful in reversing the ganglionic and skeletal muscle effects of physostigmine.
- Contact an animal poison control center for case management assistance.
Productos disponibles
Formulaciones
- Injection
Etiquetado para humanos
- Physostigmine Salicylate Injection: 1 mg/mL (contains benzyl alcohol 2% and 0.1% sodium metabisulfite) in 2 mL ampules
Estado regulador
Sin datos reguladores para: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
Store ampules below 40°C, preferably between 15-30°C. Protect from light and freezing. It should be administered IV undiluted and should not be added to IV solutions.
Información para el cliente
Este medicamento es estrictamente para uso en un entorno clínico.
- Supervisión directa: Debe administrarse en un hospital veterinario donde se disponga de supervisión veterinaria directa y monitorización de emergencia.
- No apto para uso doméstico: Debido al riesgo de efectos secundarios graves y potencialmente mortales, este fármaco nunca se dispensa para que los propietarios lo administren en casa.
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.