Rifampicin, a potent inducer of CYP3A4, reduces the AUC of
aprepitant by 91%; reduced
efficacy would be expected.
Carbamazepine, another potent inducer of CYP3A4, is predicted to interact similarly, both with
aprepitant, and its prodrug fosaprepitant.
The UK manufacturer recommends that concurrent use should be avoided.