rifampin will decrease the extent or effect of modafinil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Importance Not known.modafinil will reduce the extent or result of norgestrel by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Watch Intently. Average CYP3A4 inducers might lessen progestin concentration; … Read More