RT Journal Article T1 Pharmacokinetic interactions between cobicistat-boosted elvitegravir and darunavir in HIV-infected patients. A1 Gutierrez-Valencia, Alicia A1 Benmarzouk-Hidalgo, Omar J A1 Llaves, Silvia A1 Fernandez-Magdaleno, Tamara A1 Espinosa, Nuria A1 Viciana, Pompeyo A1 Lopez-Cortes, Luis F K1 Anti-HIV Agents K1 Drug Combinations K1 HIV Infections K1 Male K1 Young Adult AB Objectives: To evaluate if there are significant drug – drug interactions between cobicistat -boosted elvitegravir and 800 mg darunavir once daily taken simultaneously, as has been suggested previously. Methods : The study population consisted of three groups of unselected volunteers taking a regimen of elvitegravir, cobicistat , emtricitabine and tenofovir disoproxil fumarate (150, 150, 200 and 300 mg, respectively) co-formulated in a single tablet plus 800 mg darunavir (group A); only co-formulated elvitegravir, cobicistat , emtricitabine and tenofovir disoproxil fumarate (group B); and cobicistat -boosted darunavir (800 mg darunavir  + 150 mg cobicistat ) plus two nucleos(t)ide analogues (group C). Elvitegravir, cobicistat and darunavir concentrations at the end of the dosing interval (C24) were quantified using a validated LC with tandem MS method .Results: A total of 170 samples were obtained from 24, 32 and 32 patients in groups A, B and C, respectively. In group A, the elvitegravir C24 were similar to those in group B (233.67 versus 250.39 ng/mL) (P = 0.406) and the darunavir C24 were similar to those in group C (1293.54 versus 1319.34 ng/mL) (P = 0.908). The cobicistat C24 were comparable in groups A and B (20.2 versus 20.9 ng/mL) and slightly higher in group C (27.7 ng/mL) (P = 0.059).Conclusions: The results provide evidence of similar elvitegravir and darunavir C24 concentrations when these drugs are co-administered as co-formulated elvitegravir, cobicistat , emtricitabine and tenofovir disoproxil fumarate plus 800 mg darunavir or dosed separately. PB Oxford University Press YR 2017 FD 2017 LK http://hdl.handle.net/10668/10699 UL http://hdl.handle.net/10668/10699 LA en NO Gutierrez-Valencia A, Benmarzouk-Hidalgo OJ, Llaves S, Fernandez-Magdaleno T, Espinosa N, Viciana P, et al. Pharmacokinetic interactions between cobicistat-boosted elvitegravir and darunavir in HIV-infected patients. J Antimicrob Chemother. 2017 Mar 1;72(3):816-819 DS RISalud RD Aug 30, 2025