“The hepatic microsomal mixed-function oxidase activation of cyclophosphamide was inhibited by all of the following compounds: 2-diethylaminoethyl-2,2-diphenylvalerate (SKF 525A), ethylmorphine, norcodeine, 7,8-benzoflavone, acetophenetidin, metyrapone, meperidine, testosterone, progesterone , estradiol-17β, deoxycorticosterone, quinine, and probenecid.”