Piridostigmina
Pyridostigmine
Pyridostigmine bromide
También conocido como: Mestinon · Distinon · Kalymin · Regonol · pyridostigmini bromidum · Pyridostigmine bromide
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 |
|---|---|---|---|---|---|
| Myasthenia gravis (MG) | 1-3 mg/kg PO q8-12h. For animals that cannot tolerate oral medications, it may be used as an IV constant rate infusion at 0.01-0.03 mg/kg/hour. | PO/IV | q8-12h or CRI | — | 🌎 NA |
| Myasthenia gravis (MG) | 0.5-3 mg/kg PO q8-12 hours with food. | PO | q8-12h | — | 🌎 NA |
| Acquired Myasthenia gravis (MG) | 7.5-30 mg PO two times a day. | PO | BID | — | 🌎 NA |
| Myasthenia gravis (MG) | 0.5-3 mg/kg PO two to three times a day. | PO | BID-TID | — | 🌎 NA |
| Myasthenia gravis (MG) | 0.5-1 mg/kg PO two to three times a day | PO | BID-TID | — | 🌎 NA |
| Myasthenia gravis | 0.2-5 mg/kg | PO | q8-12h | — | 🌍 EU |
- Myasthenia gravis (MG): Titrate to effect to minimize adverse effects and maximize muscle strength.
- Myasthenia gravis (MG): Start low and increase slowly. Liquid formulation recommended for easy adjustment. An H2 antagonist (e.g., famotidine 5 mg/kg/day) may reduce nausea/GI irritation.
- Acquired Myasthenia gravis (MG): Begin after oral regurgitation is abolished with parenteral neostigmine. Once stable, begin corticosteroids for 2 weeks, then gradually reduce pyridostigmine.
- Myasthenia gravis (MG): If no response, add prednisone.
- Myasthenia gravis (MG): With or without prednisone (2 mg/kg PO twice daily). Spontaneous remission is not uncommon.
- Myasthenia gravis: Dose should be incrementally adjusted to maximize muscle strength and minimize adverse effects.
Gatos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Myasthenia gravis (MG) | 0.5-3 mg/kg daily PO in divided doses | PO | Divided daily | — | 🌎 NA |
| Myasthenia gravis (MG) | 1-3 mg/kg PO q8-12h | PO | q8-12h | — | 🌎 NA |
| Myasthenia gravis (MG) | 0.5-3 mg/kg PO per day | PO | Daily | — | 🌎 NA |
| Myasthenia gravis | 0.25 mg/kg | PO | q8-12h | — | 🌍 EU |
- Myasthenia gravis (MG): Dose depending on response.
- Myasthenia gravis (MG): Given with corticosteroids.
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
El bromuro de piridostigmina es un agente anticolinesterásico de amonio cuaternario sintético utilizado principalmente en medicina veterinaria para el manejo de la miastenia gravis (MG) en perros, y con menor frecuencia en gatos.
- Perla clínica: Debido a su estructura de amonio cuaternario, la piridostigmina está altamente ionizada y no atraviesa fácilmente la barrera hematoencefálica a dosis terapéuticas estándar. Esto la hace ideal para tratar trastornos de la unión neuromuscular periférica como la MG sin causar efectos secundarios significativos en el sistema nervioso central (SNC).
- Generalmente se considera mucho más eficaz para la miastenia gravis adquirida en comparación con la forma congénita de la enfermedad.
- Debido a su absorción errática y a su estrecho índice terapéutico, la dosificación debe titularse cuidadosamente según el efecto, equilibrando la mejora de la fuerza muscular frente al riesgo de toxicidad colinérgica.
Mecanismo de acción
Pyridostigmine acts as a reversible, competitive inhibitor of the enzyme acetylcholinesterase (AChE) at the neuromuscular junction.
- Mechanism: Pyridostigmine competes directly with acetylcholine (ACh) for attachment to AChE. The resulting pyridostigmine-AChE complex is hydrolyzed much more slowly than the natural ACh-AChE complex.
- Pathway: Inhibition of AChE → Decreased breakdown of ACh → Accumulation of ACh in the synaptic cleft → Prolonged and increased stimulation of nicotinic ACh receptors on the motor endplate → Enhanced skeletal muscle contraction and improved strength in myasthenic patients.
Seguridad y advertencias
Contraindicaciones
- Hypersensitivity to anticholinesterase compounds or bromides
- Mechanical or physical obstructions of the urinary tract
- Mechanical or physical obstructions of the gastrointestinal (GI) tract
- Mechanical gastrointestinal obstruction
- Mechanical urinary tract obstruction
- Peritonitis
Efectos adversos
- Nausea
- Vomiting
- Diarrhea
- Excessive salivation (ptyalism)
- Sweating (in species with sweat glands)
- Increased bronchial secretions
- Bronchospasm
- Pulmonary edema
- Respiratory paralysis
- Miosis (pupil constriction)
- Blurred vision
- Lacrimation (tearing)
- Bradycardia
- Tachycardia
- Cardiospasm
- Hypotension
- Cardiac arrest
- Muscle cramps
- Weakness (can indicate cholinergic crisis)
- Increased salivation (ptyalism)
- Diarrhoea
- Abdominal cramps
- Bronchoconstriction
- Involuntary defecation and micturition
- Nystagmus
- Heart block
- Arrhythmias
- Agitation
- Muscle weakness
- Fasciculations
Precauciones
High-Risk Patients: Use with extreme caution in patients with bronchospastic disease, epilepsy, hyperthyroidism, bradycardia or other arrhythmias, vagotonia, or GI ulcer diseases.
- Pregnancy/Nursing: FDA Category C. Excreted in maternal milk; use with caution in nursing patients.
- Dose Titration: Doses must be carefully titrated. High doses can cause a cholinergic crisis, which presents as profound weakness and can be difficult to distinguish from a myasthenic crisis.
Interacciones farmacológicas
Antagonizes the muscarinic effects of pyridostigmine. Use cautiously as it can mask early clinical signs of a life-threatening cholinergic crisis.
May decrease the anticholinesterase activity of pyridostigmine. Discontinuing corticosteroids may suddenly increase anticholinesterase activity, requiring dose adjustments.
Theoretically may have additive cholinergic effects when used concurrently.
May necessitate increased dosages of pyridostigmine when treating or diagnosing myasthenic patients.
Can antagonize anticholinesterase therapy due to its direct depressant effect on skeletal muscle.
May prolong the Phase I block of depolarizing muscle relaxants (e.g., succinylcholine) and antagonize the actions of non-depolarizing agents (e.g., pancuronium, atracurium).
May antagonize the neuromuscular effects of pyridostigmine
May antagonize the neuromuscular effects of pyridostigmine
May antagonize the neuromuscular effects of pyridostigmine
May antagonize the effects of pyridostigmine
Pyridostigmine may enhance the effect of depolarizing muscle relaxants
Pyridostigmine antagonizes the effect of non-depolarizing muscle relaxants
Pyridostigmine antagonizes the effect of non-depolarizing muscle relaxants
Monitorización
- Clinical signs of cholinergic toxicity (salivation, lacrimation, urination, defecation, GI upset, emesis, weakness)
- Efficacy of therapy (improvement in muscle strength, reduction of megaesophagus/regurgitation)
- Improvement in muscle strength and exercise tolerance
- Signs of muscarinic toxicity (hypersalivation, vomiting, diarrhea, miosis)
- Heart rate and rhythm
- Respiratory rate and effort (especially in patients with megaoesophagus)
Farmacocinética
Absorción
Marginally absorbed from the GI tract. Absorption may be erratic, especially with sustained-release tablets. Onset of action after oral dosing is generally within one hour.
Distribución
Distributed to most tissues, but does not cross into the brain (CNS), intestinal wall, fat, or thymus at usual doses due to its quaternary ammonium structure. Crosses the placenta.
Metabolismo
Metabolized by the liver and hydrolyzed by cholinesterases.
Eliminación
Excreted primarily via the kidneys (implied by class, though specific veterinary elimination data is sparse in the monograph).
Sobredosis
Overdosage of pyridostigmine can induce a life-threatening cholinergic crisis.
- Clinical Signs (SLUDGE syndrome): GI effects (nausea, vomiting, diarrhea), excessive salivation, sweating, respiratory distress (increased bronchial secretions, bronchospasm, pulmonary edema, respiratory paralysis), ophthalmic effects (miosis, blurred vision, lacrimation), cardiovascular collapse (bradycardia, tachycardia, hypotension, cardiac arrest), severe muscle cramps, and profound weakness.
- Diagnostic Challenge: Overdoses in myasthenic patients can be very difficult to distinguish from a myasthenic crisis (disease exacerbation). The time of onset of clinical signs or an edrophonium challenge (Tensilon test) may help differentiate the two.
- Treatment: Consists of immediate respiratory and cardiac supportive therapy. Atropine should be administered to antagonize muscarinic effects (refer to atropine protocols for cholinergic toxicity).
Productos disponibles
Formulaciones
- Extended-release tablets
- Injection
- 60 mg tablets
- 60 mg/5 ml oral syrup (available on import licence)
Etiquetado para humanos
- Pyridostigmine Bromide Tablets: 60 mg (Mestinon®, generic)
- Pyridostigmine Bromide Extended-Release Tablets: 180 mg (Mestinon®)
- Pyridostigmine Bromide Syrup: 12 mg/mL in 480 mL (Mestinon®)
- Pyridostigmine Bromide Injection: 5 mg/mL in 2 mL ampules (Mestinon®)
- Mestinon 60 mg tablets
Estado regulador
Human registered products often used under the cascade.
POM (Prescription Only Medicine). Oral syrup available on import licence.
Sin datos reguladores para: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
Store products at room temperature unless otherwise instructed. Protect oral solution and injection from light and freezing. Keep tablets in tight containers. Extended-release tablets may become mottled over time, but this does not affect potency. Injection is unstable in alkaline solutions.
Información para el cliente
La piridostigmina es un medicamento crucial para el manejo de la miastenia gravis de su mascota, pero la dosis debe ser muy precisa.
- Dosificación estricta: Administre este medicamento exactamente como lo recetó su veterinario. No cambie la dosis sin consultarlo, ya que la diferencia entre una dosis eficaz y una dosis tóxica es muy pequeña.
- Administración: Administrar el medicamento con comida puede ayudar a reducir el malestar estomacal. Las formas líquidas suelen ser preferibles para permitir ajustes de dosis precisos.
- Vigile la toxicidad: Contacte a su veterinario inmediatamente si nota signos de sobredosis, que incluyen: salivación excesiva, vómitos, diarrea, debilidad extrema, espasmos musculares o dificultad para respirar.
- Remisión espontánea: En algunos perros, la miastenia gravis puede resolverse por sí sola con el tiempo, por lo que su veterinario controlará a su mascota de cerca para ver si la medicación puede reducirse o suspenderse eventualmente.
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.