title: Pharmacokinetic interactions between cobicistat-boosted elvitegravir and darunavir in HIV-infected patients.
abstract: 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.
  
  
  
  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 ( C 24 ) were quantified using a validated LC with tandem MS method.
  
  
  
  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 C 24 were similar to those in group B (233.67 versus 250.39 ng/mL) ( P  =   0.406) and the darunavir C 24 were similar to those in group C (1293.54 versus 1319.34 ng/mL) ( P  =   0.908). The cobicistat C 24 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).
  
  
  
  The results provide evidence of similar elvitegravir and darunavir C 24 concentrations when these drugs are co-administered as co-formulated elvitegravir, cobicistat, emtricitabine and tenofovir disoproxil fumarate plus 800 mg darunavir or dosed separately.
authors.forename: Alicia
authors.initials: A
authors.lastname: Gutierrez-Valencia
authors.forename: Omar J
authors.initials: OJ
authors.lastname: Benmarzouk-Hidalgo
authors.forename: Silvia
authors.initials: S
authors.lastname: Llaves
authors.forename: Tamara
authors.initials: T
authors.lastname: Fernandez-Magdaleno
authors.forename: Nuria
authors.initials: N
authors.lastname: Espinosa
authors.forename: Pompeyo
authors.initials: P
authors.lastname: Viciana
authors.forename: Luis F
authors.initials: LF
authors.lastname: Lopez-Cortes
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use; D000069547:Cobicistat / Q000008:administration & dosage* / Q000627:therapeutic use; D000069454:Darunavir / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use; D004338:Drug Combinations; D004347:Drug Interactions; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D015363:Quinolones / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents; D004338:Drug Combinations; D015363:Quinolones; C509700:elvitegravir; D000069547:Cobicistat; D000069454:Darunavir