This study examined darunavir (DRV) concentrations in 8 HIV-positive patients taking DRV 800 mg daily combined with the fixed-dose combination Stribild (elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate). The results showed median DRV concentrations were 80% lower than when taken with ritonavir and over half of concentrations were below the therapeutic target. While most patients' viral loads were suppressed, 3 experienced viral blips. The study concludes this regimen may not be preferable due to the risk of subtherapeutic DRV levels negatively impacting long-term virologic response, and alternative treatment options should be