Quantitative disposition of cyclophosphamide (CY) indicating fraction of dose eliminated by pathway.

Chloroacetaldehyde (CAA), acrolein, and phosphoramide mustard (PM) are cytotoxins, but acrolein and PM are the major toxins because of the abundance of their formation. HCY (4-hydroxy-cyclophosphamide) is formed primarily in the liver but circulates in blood, entering cells as its tautomer aldocyclophosphamide (AldoCY). Acrolein and PM are formed from AldoCY when it decomposes through β-elimination. Other metabolites include o-carboxyethyl-phosphoramide mustard (CEPM), deschloroethyl-cyclophosphamide (DCCY), 4-keto-cyclophosphamide (KetoCY), hydroxypropyl-phosphoramide mustard (HPPM), imino-cyclophosphamide (IminoCy), and glutathionyl-cyclophosphamide (GSCY).