Coadministration has not been studied. Aripiprazole is metabolized by CYP3A4 and CYP2D6. Darunavir/cobicistat could potentially increase aripiprazole concentrations. Monitor adverse effects and decrease aripiprazole dosage if needed. The European product label for aripiprazole advises reducing the aripiprazole dose to approximately one-half of its prescribed dose when given with potent inhibitors of CYP3A4, such as HIV protease inhibitors. Emtricitabine and tenofovir alafenamide do not interact with this metabolic pathway.