Carbimazol
Carbimazole
Thioimidazole-derivative antithyroid drug
También conocido como: Vidalta · Neo-Carbimazole · Carbazole · Basolest · Camazol · Carbistad · Neo Tomizol · NeoMercazole · Neo-Thyreostat · Thyrostat · Tyrazol · Neo-morphazole · Neo-Mercazole · carbimazolum
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 |
|---|---|---|---|---|---|
| Hyperthyroidism | 15 mg/animal (starting dose) or 10 mg/animal if total thyroxine <100 nmol/l. Adjust dose in 5 mg increments. | PO | q24h | Long-term | 🌍 EU |
- Hyperthyroidism: Do not break tablets. Note: There are no data on the use of the sustained-release formulation in dogs.
Gatos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Hyperthyroidism | 2.5-5 mg (total dose) per cat | PO | twice daily | — | 🌎 NA |
| Hyperthyroidism | 10-15 mg total dose daily per cat in divided doses | PO | divided doses | for 1-3 weeks | 🌎 NA |
| Hyperthyroidism | Initially, give 5 mg (total dose) | PO | q8h | for 2-3 weeks | 🌎 NA |
| Hyperthyroidism (Sustained-release tablets) | 15 mg | PO | once daily | — | 🌎 NA |
| Hyperthyroidism | 15 mg/animal (starting dose) or 10 mg/animal if total thyroxine <100 nmol/l. Adjust dose in 5 mg increments. | PO | q24h | Long-term | 🌍 EU |
- Hyperthyroidism: Will produce a euthyroid state for most patients. Then adjust dosage for the patient to the lowest effective dose. Most cats will need dosing at least once daily.
- Hyperthyroidism: Then adjust. May need to increase dose in approximately 10% of cats. Most cats require 5 mg PO q12h to maintain euthyroidism.
- Hyperthyroidism (Sustained-release tablets): Give at the same time each day. Do not break or crush tabs. Adjust dose upwards or downwards within a range of 10 mg-25 mg per day in 5 mg increments depending on clinical signs and TT4. If cat requires doses less than 10 mg per day, use alternative treatment.
- Hyperthyroidism: Do not break tablets.
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
El carbimazol es un medicamento antitiroideo derivado del tioimidazol utilizado principalmente en medicina veterinaria para el tratamiento del hipertiroidismo felino.
- Actúa como un profármaco y se convierte rápidamente in vivo en metimazol.
- Debido a que carece del sabor amargo del metimazol, suele ser mejor tolerado por los gatos, lo que reduce la incidencia de efectos secundarios gastrointestinales.
- Aunque no está disponible en EE. UU. ni en Canadá, se utiliza ampliamente en Europa y otras regiones.
- Perla clínica: El carbimazol requiere aproximadamente el doble de la dosis en miligramos que el metimazol para alcanzar niveles séricos equivalentes debido a las diferencias en el peso molecular.
Mecanismo de acción
Carbimazole is a prodrug that is almost entirely converted to methimazole in the body.
- Methimazole actively inhibits the enzyme thyroid peroxidase (TPO).
- Inhibition of TPO → blocks the oxidation of iodide to iodine → prevents iodine incorporation into tyrosyl residues of thyroglobulin.
- It also inhibits the coupling of iodinated tyrosyl residues (monoiodotyrosine and diiodotyrosine) → prevents formation of thyroxine (T4) and triiodothyronine (T3).
- Note: It does not affect the release or activity of pre-formed thyroid hormones already in circulation, which accounts for the 1-3 week lag time before clinical improvement is seen.
Seguridad y advertencias
Contraindicaciones
- Hypersensitivity to carbimazole or methimazole
- Not recommended in cats intolerant to methimazole
- History of or concurrent hematologic abnormalities
- Liver disease
- Autoimmune disease
Efectos adversos
- Vomiting
- Anorexia
- Depression
- Eosinophilia (usually transient)
- Leukopenia (usually transient)
- Lymphocytosis (usually transient)
- Self-induced excoriations (rare but serious)
- Bleeding (rare but serious)
- Hepatopathy (rare but serious)
- Thrombocytopenia (rare but serious)
- Agranulocytosis (rare but serious)
- Positive direct antiglobulin test (rare but serious)
- Acquired myasthenia gravis (rare but serious)
- Positive ANA (with chronic use)
Precauciones
Hypersensitivity: Contraindicated in patients hypersensitive to carbimazole or methimazole. Cross-Reactivity: Because carbimazole is a prodrug converted into methimazole, cats who have had prior serious reactions to methimazole should receive carbimazole with great caution. Pregnancy/Nursing: High levels of methimazole cross the placenta and may induce hypothyroidism in kittens. Levels higher than those found in plasma are found in breast milk. Kittens should be placed on a milk replacer after receiving colostrum from mothers on methimazole. FDA categorizes methimazole as category D for use during pregnancy.
Interacciones farmacológicas
Potential for increased risk for hepatotoxicity; increased monitoring (LFT's) necessary
Carbimazole may decrease digoxin efficacy
Potential for decreased anticoagulant efficacy if carbimazole added
Carbimazole interferes with the uptake and efficacy of radioiodine therapy. It must be discontinued prior to treatment.
Concurrent use is not recommended as it may interfere with the dietary management of hyperthyroidism.
Monitorización
- CBC, platelet counts (baseline and every 2-3 weeks during first 3 months)
- Serum T4 (baseline and every 2-3 weeks during first 3 months)
- Liver function tests (if indicated by clinical signs)
- ANA (if indicated by clinical signs)
- T4 at 3-6 month intervals (after stabilized)
- Other diagnostic tests as dictated by adverse effects
Farmacocinética
Vida media
Absorción
Rapidly absorbed from the GI tract.
Distribución
In cats, the volume of distribution of methimazole is variable (0.12-0.84 L/kg). Methimazole apparently concentrates in thyroid tissue and biologic effects persist beyond measurable blood levels. Crosses the placenta and enters breast milk.
Metabolismo
Rapidly and nearly totally converted to methimazole in vivo.
Eliminación
Plasma elimination half-life of methimazole ranges from 2.3-10.2 hours in cats and 8-9 hours in dogs.
Sobredosis
Acute toxicity that may be seen with overdosage includes vomiting, anorexia, depression, and more serious effects such as agranulocytosis, hepatopathy, and thrombocytopenias.
Treatment: Consists of following standard protocols in handling an oral ingestion (empty stomach if not contraindicated, administer charcoal, etc.) and treating symptomatically and supportively.
Productos disponibles
Formulaciones
- Oral Tablets
- Oral Sustained-Release Tablets
Veterinario
- Carbimazole Oral Sustained-Release Tablets: 10 mg & 15 mg (Vidalta, Intervet-UK)
Etiquetado para humanos
- Carbimazole Oral Tablets: 5 mg & 20 mg (NeoCarbimazole, Carbazole, Neo Mercazole)
Estado regulador
Approved for feline hyperthyroidism.
POM-V (Prescription Only Medicine - Veterinarian)
Sin datos reguladores para: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
Unless otherwise labeled, carbimazole tablets should be stored at room temperature in well-closed containers.
Información para el cliente
- Propósito: Este medicamento controla la glándula tiroides hiperactiva de su gato (hipertiroidismo) reduciendo la producción de hormonas tiroideas. Es una herramienta de control, no una cura.
- La paciencia es clave: Por lo general, toma de 1 a 3 semanas observar una mejoría significativa en los síntomas de su gato.
- Administración: Administre exactamente según lo prescrito. No triture ni rompa las tabletas de liberación sostenida (como Vidalta).
- Efectos secundarios a vigilar: Comuníquese con su veterinario si su gato presenta vómitos, pérdida de apetito, letargo o rascado/picazón facial severa.
- Seguridad: Las mujeres embarazadas o en período de lactancia deben manipular este medicamento con precaución (usar guantes), ya que puede atravesar la placenta y pasar a la leche materna.
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.