Coadministration has not been studied. Isavuconazole is metabolised by CYP3A4/5 and UGTs and is a moderate inhibitor of CYP3A4. No effect on isavuconazole is expected as doravirine does not inhibit or induce CYP enzymes. However, doravirine is metabolized by CYP3A4 and isavuconazole is predicted to increase doravirine exposure, although to a limited extent. No dose adjustment of doravirine is required as phase I trials showed a good tolerability of doravirine with up to a 3-4 fold increase in exposure.