 Modafinil induces the cytochrome P450 enzymes CYP1A2, CYP3A4, and CYP2B6, as well as inhibiting CYP2C9 and CYP2C19 "in vitro".It may also induce P-glycoprotein (Pgp), which may affect drugs transported by Pgp, such as digoxin.The bioavailability of modafinil is greater than 80% of the administered dose.