Monthly Archives: March 2018

CYCLOPHOSPHAMIDE PROTOCOL FOR RPGN

Cyclophosphamide for RPGN

  1. ONE HOUR PRIOR THE INFUSION HYDRATES WITH 500CC NORMAL SALINE FOR ONE HOUR.
  2. HALF AN HOUR PRIOR THE INFUSION GIVE :-
    • ONDANSETRON 8MG TAB (ONE TAB.) STAT
    • MESNA(UROMETEXAN) 200MG IN 100CC NORMAL SALINE IV OVER 30 MIN.
  3. CYCLOPHOSPHAMIDE(ENDOXAN) INFUSION AS FOLLOW:
    1000MG + MESNA 400 MG IN 500CC NORMAL SALINE TO BE INFUSED OVER ONE HOUR.

(DOSE OF CYCLOPHOSPHAMIDE IS 0.75GM/M2  BSA ).

  • FOLLOWING CYCLOPHOSPHAMIDE INFUSION, HYDRATE WITH 500CC NORMAL SALINE FOR ONE HOUR.

Cyclophosphamide

Mechanism of Action

Cyclophosphamide is an alkylating agent that prevents cell division by cross-linking DNA strands and decreasing DNA synthesis. It is a cell cycle phase nonspecific agent. Cyclophosphamide also possesses potent immunosuppressive activity. Cyclophosphamide is a prodrug that must be metabolized to active metabolites in the liver.

Pharmacodynamics/Kinetics

Absorption: Oral: Well absorbed

Distribution: Vd: 30 to 50 L (approximates total body water); crosses into CSF (not in high enough concentrations to treat meningeal leukemia)

Protein binding: ~20%; some metabolites are bound at >60%

Metabolism: Hepatic to active metabolites acrolein, 4-aldophosphamide, 4-hydroperoxycyclophosphamide, and nor-nitrogen mustard

Bioavailability: >75%

Half-life elimination: IV: 3 to 12 hours; Children: 4 hours; Adults: 6 to 8 hours

Time to peak: Oral: ~1 hour; IV: Metabolites: 2 to 3 hours

Excretion: Urine (10 to 20% as unchanged drug); feces (4%)

>