Drug Interaction Report

The concomitant use of modafinil may theoretically alter the metabolic activation and inactivation of ifosfamide and cyclophosphamide. Modafinil is a modest CYP450 2B6 and 3A4 inducer in vitro. Ifosfamide and cyclophosphamide are substrates of these isoenzymes. If these drugs are to be used together, close monitoring of the patient for altered efficacy and safety is recommended.

Administration with food may delay the absorption of modafinil (the racemate) and armodafinil (the R-enantiomer) without significantly affecting their overall bioavailability. According to the product labeling, modafinil's absorption may be delayed by approximately one hour if taken with food. Similarly, the time to reach peak plasma concentration (Tmax) of armodafinil may be delayed by approximately 2 to 4 hours in the fed state.