Inductive effects of phenytoin (FLU/^TBU; n = 22) compared with no phenytoin (TBI; n = 9) on cyclophosphamide metabolism. Boxplot shows median and interquartile ranges (25th and 75th percentile) of respective analyte AUC_0-48h (μM⋅h). A statistically significant difference was observed between preparative regimens for the AUC of CY (P < .0001) and ketoCY (P = .03), but not the AUCs of CEPM and DCCY (P = .05 and 0.14; respectively).