Aprepitant inhibits the enzymes involved in the
metabolism of
pimozide, and is therefore expected to raise
pimozide levels, which may result in potentially fatal torsade de pointes arrhythmias. Fosaprepitant, a prodrug of
aprepitant, would be expected to interact similarly.
Concurrent use is contraindicated. Caution is needed in the 2 weeks after
aprepitant is stopped as there may be some residual
enzyme inhibiting activity.