Effect: Posaconazole may increase the plasma concentrations of aprepitant.
Clinical management: Caution should be exercised upon coadministration of these drugs. Monitor for increased toxicity of aprepitant.
Probable mechanism: Inhibition of the cytochrome P450 (CYP) 3A4-mediated biotransformation by posaconazole.
Summary: Although not studied for posaconazole, coadministration of ketoconazole (400 mg/day for 10 days, a strong CYP3A4-inhibitor) and aprepitant (125 mg single dose on day 5) increased the AUC and half-life of aprepitant by five-fold and three-fold, respectively. Coadministration with the CYP3A4-inhibitor posaconazole could result in similar effects.
- SPC Aprepitant
QT effectPosaconazole: Conditional QT risk
Substantial evidence reports that this drug causes QT prolongation and has a risk of TdP, but only under certain known conditions (e.g. excessive dose, drug interaction, etc.).