Cyclophosphamide (Cytoxan)

Indications :

• FDA Indications:
  • Malignant lymphomas stages III and IV (Hodgkin and Non-Hodgkin lymphoma, lymphocytic lymphoma, small lymphocytic lymphoma, Burkitt lymphoma, and multiple myeloma)
  • Solid tumors:
    • Breast cancer
    • Disseminated neuroblastoma/retinoblastoma
    • Ovarian adenocarcinoma
  • Immunosuppressant
    • Minimal change disease
    • MS
  • Transplant
    • Prevention of rejection and GVHD
• Used in regimens such as:
  • R-CHOP
  • CyBorD
  • CVAD

Dosing :

• High-dose is used in cancer, while lower dosages have shown merit for use in selective immunomodulation of regulatory T cells

MoA :

• Nitrogen mustard drug which permanently alkylates/cross-links DNA and eventually leads to programmed cell death.
  • Metabolized to active form by CyP-450
  • Metabolism also forms toxic byproduct Acrolein which is the principal cause of hemorrhagic cystitis
• Not cell-cycle phase-specific

Pharmacokinetics :

Toxicities/Monitoring :

• Metabolic byproduct Acrolein causes hemorrhagic cystitis. Use Mesna for prophylaxis alongside IV fluids/PO hydration
  • UA may be used to monitor for hemorrhagic cystitis
• Myelosupression - Monitor CBC

References:

• https://www.ncbi.nlm.nih.gov/books/NBK553087/