title: Nonnucleoside reverse transcriptase inhibitor fold change or plasma concentration as a predictor of virological response over 48 weeks in highly treatment experienced HIV-positive individuals.
abstract: The nonnucleoside reverse transcriptase inhibitors (NNRTI) have low genetic barriers to resistance. Resistance can sometimes be overcome by increasing drug exposure. We assessed factors associated with 48-week virological response in treatment-experienced individuals receiving NNRTI therapy including resistance testing results and plasma drug exposure. Of 62 individuals assigned a new NNRTI-based regimen following resistance testing therapy consisted of efavirenz in 35 (56%) and nevirapine in 27 (44%) individuals. NNRTI fold change (FC) was determined from resistance test at baseline and plasma drug concentration at week 4. Mean time weighted change from baseline VL was -0.68 log over 48 weeks. Significant associations with change from baseline VL included baseline VL and FC whereas plasma drug concentration was not associated. In this cohort of highly treatment-experienced individuals treated with NNRTI regimens, we did not observe a significant association between NNRTI plasma concentration and virological response.
authors.affiliation: National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, NSW 2010, Australia. alan_winston71@yahoo.co.uk
authors.forename: Alan
authors.initials: A
authors.lastname: Winston
authors.forename: Janaki
authors.initials: J
authors.lastname: Amin
authors.forename: Gill
authors.initials: G
authors.lastname: Hales
authors.forename: David A
authors.initials: DA
authors.lastname: Cooper
authors.forename: Sean
authors.initials: S
authors.lastname: Emery
mesh_terms: D000480:Alkynes; D019380:Anti-HIV Agents / Q000097:blood / Q000627:therapeutic use*; D048588:Benzoxazines; D015331:Cohort Studies; D003521:Cyclopropanes; D005500:Follow-Up Studies; D006679:HIV Seropositivity; D015497:HIV-1; D006801:Humans; D016014:Linear Models; D019829:Nevirapine / Q000097:blood / Q000627:therapeutic use*; D010078:Oxazines / Q000097:blood / Q000627:therapeutic use*; D012367:RNA, Viral / Q000097:blood; D018894:Reverse Transcriptase Inhibitors / Q000097:blood / Q000627:therapeutic use*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000480:Alkynes; D019380:Anti-HIV Agents; D048588:Benzoxazines; D003521:Cyclopropanes; D010078:Oxazines; D012367:RNA, Viral; D018894:Reverse Transcriptase Inhibitors; D019829:Nevirapine; C098320:efavirenz