VetSheet

Ciclofosfamida

Cyclophosphamide

N,N-bis(2-chloroethyl)-1,3,2-oxazaphosphinan-2-amine 2-oxide

Antineoplásico / Inmunosupresor (Agente alquilante)POIVPerrosGatosPequeños mamíferosCaballosOvejas

También conocido como: Cytoxan · Neosar · Procytox · Endoxana · CPM · CTX · B-518 · ciclofosfamida · cyclophosphamidum · cyclophosphanum · NSC-26271 · WR-138719 · Cytophosphane

Revisado por el equipo veterinario de VetSheetActualizado 5 abr 2026Referencia veterinaria basada en la evidencia

1.5 mg/kg (>30 kg), 2 mg/kg (15-30 kg), 2.5 mg/kg (<15 kg) PO daily on 4 consecutive days each weekPO· 4 days/week· 2-4 months (max 4 months)
🐕

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

IndicaciónDosisVíaFrecuenciaDuraciónRegión
To inhibit local recurrence in dogs with incompletely resected soft tissue sarcomas10 mg/m2 PO once daily with piroxicam at 0.3 mg/kg PO once dailyPOq24hContinuous (metronomic)🌎 NA
Antineoplastic50 mg/m2 PO 4 days/week OR 250 mg/m2 PO once every 3 weeks OR 100-300 mg/m2 IV weeklyPO/IVVariesProtocol dependent🌎 NA
Immunosuppressant (IMHA/ITP)50 mg/m2 PO every 2nd dayPOq48hAdjust to manage side effects🌎 NA
Immunosuppressant (IMHA pulse therapy)50 mg/m2 PO daily for 4 days on, 3 days offPOPulseOngoing🌎 NA
Polyarthritis1.5 mg/kg (>30 kg), 2 mg/kg (15-30 kg), 2.5 mg/kg (<15 kg) PO daily on 4 consecutive days each weekPO4 days/week2-4 months (max 4 months)🌎 NA
Glomerulonephritis2.2 mg/kg PO q24h for 4 days, discontinue for 3 days and then repeatPOPulseOngoing🌎 NA
Lymphoma (COP low dose protocol - Induction)50 mg/m2POalternate days OR first 4 days of each weekFirst 2 months🌍 EU
Lymphoma (COP low dose protocol - Maintenance after 2 months)50 mg/m2POalternate days OR first 4 days of each second weekMonths 2 to 6🌍 EU
Lymphoma (COP low dose protocol - Maintenance after 6 months)50 mg/m2POq48h (one week in three) OR first 4 days of each third weekMonths 6 to 12🌍 EU
  • To inhibit local recurrence in dogs with incompletely resected soft tissue sarcomas: If unacceptable adverse effects develop, increase interval to every other day.
  • Antineoplastic: Consult veterinary oncologist.
  • Immunosuppressant (IMHA/ITP): Used with glucocorticoids.
  • Immunosuppressant (IMHA pulse therapy): Alternatively 50 mg/m2 PO every other day.
  • Polyarthritis: Given with prednisolone.
  • Lymphoma (COP low dose protocol - Induction): Co-administer with 1 mg/kg furosemide q12h on treatment days to reduce cystitis risk.
  • Lymphoma (COP low dose protocol - Maintenance after 2 months): Alternate-week therapy.
  • Lymphoma (COP low dose protocol - Maintenance after 6 months): Stop and monitor for relapse after 12 months.

Gatos

IndicaciónDosisVíaFrecuenciaDuraciónRegión
Immunosuppressant (ITP or IMHA)50 mg/m2 PO every 2nd dayPOq48hOngoing🌎 NA
To slow progression of FIP2-4 mg/kg PO four times a weekPO4 times/weekOngoing🌎 NA
  • Immunosuppressant (ITP or IMHA): Author prefers cyclosporine or chlorambucil in cats.

Pequeños mamíferos

IndicaciónDosisVíaFrecuenciaDuraciónRegión
Antineoplastic (lymphoma) in rabbits50 mg/m2 PO daily for 3 days each week OR 100-200 mg/m2 IV every 7 daysPO/IVVariesProtocol dependent🌎 NA
  • Antineoplastic (lymphoma) in rabbits: Consider fully implantable vascular access device for IV.

Caballos

IndicaciónDosisVíaFrecuenciaDuraciónRegión
Neoplastic diseases200 mg/m2 (usually 1 gram per horse per dose) IV every 1-2 weeksIVq1-2 weeksProtocol dependent🌎 NA
  • Neoplastic diseases: Consult veterinary oncologist.

Ovejas

IndicaciónDosisVíaFrecuenciaDuraciónRegión
Chemical shearing agentHistorical usePO/IVSingleSingle🌎 NA
  • Chemical shearing agent: Historical use only.

Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.

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Resumen

La ciclofosfamida es un potente agente antineoplásico e inmunosupresor utilizado ampliamente en medicina veterinaria para perros y gatos.

  • Uso antineoplásico: Empleado en protocolos combinados para linfomas, leucemias, carcinomas y sarcomas. La terapia metronómica (continua) de dosis baja también se utiliza para prevenir la recurrencia de sarcomas.
  • Uso inmunosupresor: Utilizado para enfermedades mediadas por el sistema inmunitario graves como el lupus eritematoso sistémico (LES), trombocitopenia inmunomediada (TIM), anemia hemolítica inmunomediada (AHIM) y pénfigo.

Perla clínica: La ciclofosfamida no es específica de la fase del ciclo celular. Debido a que es un profármaco que requiere activación hepática, no es un agente vesicante y puede administrarse de forma segura a través de venas periféricas, a diferencia de muchos otros agentes quimioterapéuticos.

Mecanismo de acción

Cyclophosphamide is a prodrug that is metabolized in the liver by cytochrome P450 enzymes into active metabolites, primarily phosphoramide mustard and acrolein.

Phosphoramide mustard → acts as an alkylating agent → forms cross-links within and between DNA strands → interferes with DNA replication and RNA transcription → triggers apoptosis and cell death.

Acrolein is a toxic byproduct that concentrates in the urinary bladder and is responsible for sterile hemorrhagic cystitis. The drug also profoundly suppresses B-cell and T-cell function, leading to its immunosuppressive effects.

Seguridad y advertencias

Contraindicaciones

  • Prior anaphylactic reactions to the drug
  • Severe pre-existing myelosuppression (leukopenia, thrombocytopenia)
  • Active infections where immunosuppression may be dangerous
  • No specific contraindications available in the monograph, but clinically contraindicated in patients with severe pre-existing myelosuppression or active haemorrhagic cystitis.
  • Pre-existing severe myelosuppression

Efectos adversos

  • Myelosuppression (leukopenia, thrombocytopenia, anemia)
  • Gastroenterocolitis (anorexia, nausea, vomiting, diarrhea)
  • Sterile hemorrhagic cystitis (induced by acrolein metabolite)
  • Alopecia (especially in continuously growing coats like Poodles and Old English Sheepdogs)
  • Pulmonary infiltrates and fibrosis
  • Hyponatremia
  • Secondary leukemia
  • Myelosuppression (nadir usually 5-14 days post-therapy)
  • Sterile haemorrhagic cystitis (caused by acrolein metabolite)
  • Bladder fibrosis
  • Transitional cell carcinoma (secondary to chronic cystitis)
  • Diarrhoea
  • Hepatotoxicity
  • Nephrotoxicity
  • Reduction in hair growth rate / Alopecia
  • Gastrointestinal toxicity

Precauciones

WARNING: Cyclophosphamide is potentially teratogenic and embryotoxic. Safe use in pregnancy is not established.

  • Hemorrhagic Cystitis: Up to 30% of dogs on long-term therapy may develop sterile hemorrhagic cystitis. Encourage frequent urination and water intake. Co-administration of furosemide may reduce risk.
  • Myelosuppression: Monitor CBC closely. Delay doses if severe leukopenia or thrombocytopenia occurs.
  • Handling: Cytotoxic precautions must be taken. Do not split or crush tablets. Avoid direct contact with urine or feces of treated animals.

Interacciones farmacológicas

Allopurinol

May increase the myelosuppression caused by cyclophosphamide

DoxorubicinMajor

Potentiation of cardiotoxicity may occur

ChloramphenicolModerate

May inhibit cyclophosphamide metabolism

Phenobarbital

May increase the rate of metabolism to active metabolites, increasing toxicity risk

Thiazide DiureticsMajor

May increase the myelosuppression caused by cyclophosphamide

Succinylcholine

Metabolism may be slowed, prolonging effects due to decreased pseudocholinesterases

DigoxinModerate

Absorption of orally administered digoxin may be decreased (may occur several days after dosing)

BarbituratesMajor

Increase cyclophosphamide toxicity due to increased rate of conversion to metabolites

PhenothiazinesModerate

Reduce cyclophosphamide efficacy

OndansetronModerate

Reduce cyclophosphamide efficacy

InsulinModerate

Insulin requirements are altered by concurrent cyclophosphamide

cimetidineMajor

Inhibits hepatic cytochrome P450 enzyme pathway, potentially altering the metabolism and increasing toxicity of chemotherapeutics.

Monitorización

  • Efficacy (tumor response or remission of immune-mediated disease)
  • Complete Blood Count (CBC) regularly for myelosuppression (nadir typically 7-14 days)
  • Urinalysis regularly for signs of sterile hemorrhagic cystitis (hematuria)
  • Uric acid levels (blood and urine)
  • White Blood Cell (WBC) count (regular monitoring recommended due to myelosuppression)
  • Urinalysis (monitor for haematuria indicating sterile haemorrhagic cystitis)
  • Renal and hepatic function panels
  • Free-catch urine by dipstick prior to and each week of treatment
  • Haematology
  • Biochemistry (prior to first treatment and minimum every 6 months)

Farmacocinética

Vida media

Perros4-12 hours

Absorción

Well absorbed after oral administration with peak levels occurring about 1 hour after dosing.

Distribución

Distributed throughout the body, including CSF (subtherapeutic levels). Minimally protein bound. Distributes into milk and crosses the placenta.

Metabolismo

Metabolized in the liver to several active and inactive metabolites (including phosphoramide mustard and acrolein).

Eliminación

Majority of the drug is excreted as metabolites and unchanged drug in the urine.

Sobredosis

Limited information on acute overdoses. The lethal dose in dogs is reported as 40 mg/kg IV.

If an oral overdose occurs, perform gut emptying (emesis/lavage) if indicated and hospitalize the animal for aggressive supportive care, including IV fluids to flush the bladder and prevent hemorrhagic cystitis.

Productos disponibles

Formulaciones

  • Oral tablets
  • Powder for injection
  • Compounded oral elixir/suspension
  • Injectable: 100 mg, 200 mg, 500 mg, 1000 mg powder for reconstitution
  • Oral: 50 mg tablets

Etiquetado para humanos

  • Cyclophosphamide Tablets: 25 mg & 50 mg
  • Cyclophosphamide Powder for Solution for Injection: 500 mg, 1 g and 2 g
  • Endoxana 50 mg tablets
  • Endoxana 100 mg, 200 mg, 500 mg, 1000 mg powder for reconstitution

Estado regulador

European Union✓ AprobadoMedicamento de prescripciónEMA
🐕 Dogs🐈 Cats

Often requires compounding by specialized pharmacies (e.g., ChemoPet) for accurate veterinary dosing.

United Kingdom✓ AprobadoMedicamento de prescripciónVMD
🐕 Dogs🐈 Cats

Often requires compounding by specialized pharmacies (e.g., ChemoPet) for accurate veterinary dosing.

Sin datos reguladores para: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU

Almacenamiento y estabilidad

Store tablets and powder for injection at <25°C (brief excursions up to 30°C permitted). Store tablets in tight containers. Reconstituted injection is stable for 24 hours at room temperature or 6 days refrigerated. Compounded oral elixir is stable for 14 days refrigerated.

Información para el cliente

Advertencia de seguridad importante: Este es un fármaco quimioterapéutico potente. Siga cuidadosamente todas las instrucciones de manipulación.

  • Manipulación: No rompa ni triture las tabletas. Lávese bien las manos después de manipularlas. Evite el contacto directo con la orina, heces o vómito de su mascota mientras esté bajo este tratamiento.
  • Micción: Saque a pasear a su perro con frecuencia para fomentar la micción, especialmente por la mañana. Esto ayuda a prevenir la irritación de la vejiga.
  • Cuándo llamar al veterinario: Contacte a su veterinario inmediatamente si nota sangre en la orina, esfuerzo al orinar, sangrado anormal, hematomas, letargo severo, vómitos o diarrea.

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.