CHOP / CEOP Chemotherapy Protocol
The **25-week CHOP/CEOP protocol** is a standard multi-agent chemotherapy regimen used primarily for the treatment of intermediate to high-grade lymphoma in dogs. It utilizes a rotating schedule of drugs with different mechanisms of action to maximize tumor cell kill while minimizing overlapping toxicities. > **Critical Warning:** Vincristine and Doxorubicin/Epirubicin are severe **vesicants**. Intravenous catheters must be placed in all cases, and ONLY catheters placed by a clean 'first-stick' should be used. If extravasation occurs, contact an oncologist immediately. **Clinical Pearl:** Furosemide is co-administered with cyclophosphamide to induce diuresis, significantly reducing the contact time of toxic metabolites (acrolein) with the bladder mucosa, thereby minimizing the risk of sterile haemorrhagic cystitis.
Mecanismo: This protocol relies on the synergistic action of four distinct drug classes: * **Cyclophosphamide:** Alkylating agent → cross-links DNA strands, preventing replication. * **Doxorubicin/Epirubicin:** Anthracycline antibiotic → inhibits **topoisomerase II**, intercalates DNA, and generates free radicals. * **Vincristine:** Vinca alkaloid → binds to **tubulin**, inhibiting microtubule formation and arresting cells in metaphase. * **Prednisolone:** Glucocorticoid → induces apoptosis in lymphoid cells.
Dosificación por especie
- Lymphoma (CHOP/CEOP Protocol - Vincristine) · 0.7 mg/m2 · IV · once · Weeks 1, 3, 6, 8, 11, 15, 19, 23 · Strict first-stick IV catheter only. Vesicant.
- Lymphoma (CHOP/CEOP Protocol - Prednisolone) · 2 mg/kg (Wk 1); 1.5 mg/kg (Wk 2); 1 mg/kg (Wk 3); 0.5 mg/kg (Wk 4) · PO · q24h · First 4 weeks only, then stopped · Tapering dose.
- Lymphoma (CHOP/CEOP Protocol - Cyclophosphamide) · 250 mg/m2 · PO/IV · once · Weeks 2, 7, 13, 21 · Administer with Furosemide.
- Lymphoma (CHOP/CEOP Protocol - Furosemide) · 1 mg/kg · PO · q12h · For 48h (4 doses) concurrent with cyclophosphamide · To prevent haemorrhagic cystitis.
- Lymphoma (CHOP/CEOP Protocol - Doxorubicin or Epirubicin) · 30 mg/m2 (Use 1 mg/kg for patients <15 kg) · IV · once · Weeks 4, 9, 17, 25 · Give in 0.9% NaCl (not Hartmann's) over 20 minutes. Vesicant.
- Lymphoma (CHOP/CEOP Protocol - Maropitant) · 1 mg/kg · SC · once · Prior to doxorubicin/epirubicin · Anti-emetic premedication.
- Lymphoma (CHOP/CEOP Protocol - Omeprazole) · 1 mg/kg · PO · q12h or q24h · First 21 days · GI protectant. Ranitidine with sucralfate is an alternative.
- Lymphoma (Alternative to Cyclophosphamide - Chlorambucil) · 20 mg/m2 · PO · once · As needed · Used if haemorrhagic cystitis develops.
- Lymphoma (Alternative to Doxorubicin - Mitoxantrone) · 5.5 mg/m2 · IV · once · As needed · Given over 10 minutes. Used in cases of cardiac dysfunction.
Las dosis son una referencia clínica para médicos veterinarios. Confirme siempre con la información vigente del producto y el paciente individual.
Vías de administración
Contraindicaciones
- Severe myelosuppression (neutrophil count < 3 x 10^9/l)
- Pre-existing severe cardiac dysfunction (relative contraindication for doxorubicin; use mitoxantrone instead)
- Active haemorrhagic cystitis (substitute cyclophosphamide with chlorambucil)
- MDR1 mutation (requires significant dose reduction or avoidance of vincristine and doxorubicin)
Efectos adversos
- Myelosuppression (neutropenia, thrombocytopenia)
- Gastrointestinal toxicity (vomiting, diarrhea, anorexia)
- Haemorrhagic cystitis (specific to cyclophosphamide)
- Severe tissue necrosis if extravasated (vincristine, doxorubicin)
- Cardiotoxicity (specific to doxorubicin)
- Alopecia (breed dependent)
Interacciones farmacológicas
- Cimetidine · Alters hepatic cytochrome P450 enzyme pathway, potentially altering the metabolism and increasing toxicity of chemotherapeutics. · major
Monitoreo
- Haematology prior to each treatment
- Nadir neutrophil count 7 days after the first doxorubicin treatment
- Free-catch urine dipstick prior to each cyclophosphamide administration (check for blood)
- Urine culture if blood is noted on dipstick
- Biochemistry prior to first treatment and minimum every 6 months
- Baseline echocardiography (especially before doxorubicin if pre-existing heart disease is suspected)
Sobredosis
Overdosage of any component of the CHOP protocol can lead to **life-threatening myelosuppression** (profound neutropenia and sepsis), severe gastrointestinal mucosal sloughing, and acute cardiotoxicity (doxorubicin). Treatment is strictly supportive, including broad-spectrum IV antibiotics, aggressive fluid therapy, anti-emetics, and potentially granulocyte colony-stimulating factor (G-CSF).
La referencia de fármacos de VetSheet está destinada a médicos veterinarios como apoyo a la decisión clínica; no sustituye el juicio profesional ni la información vigente del fabricante.