The Biotransformation of Cyclophosphamide in Man: Influence of Prednisone

The effect of corticosteroid on the rate of biotransformation of cyclophosphamide in man was studied. Two opposite effects could be demonstrated. The immediate effect consisted of an inhibition of the biotransformation probably due to the inhibition of the hepatic drug-metabolizing enzymes whereas prolonged treatment with prednisone resulted in an increased rate of biotransformation of cyclophosphamide, probably due to the induction of the same enzyme system.