title: Differential effects of efavirenz, lopinavir/r, and atazanavir/r on the initial viral decay rate in treatment naïve HIV-1-infected patients.
abstract: Initial viral decay rate may be useful when comparing the relative potency of antiretroviral regimens. Two hundred twenty-seven ART-naïve patients were randomized to receive efavirenz (EFV) (n = 74), lopinavir/ritonavir (LPV/r) (n = 77), or atazanavir/ritonavir (ATV/r) (n = 79) in combination with two NRTIs. The most frequently used NRTI combinations in the EFV and ATV/r groups were the nonthymidine analogues tenofovir and emtricitabine or lamivudine (70% and 68%, respectively) and, in the LPV/r group, lamivudine and the thymidine analogue zidovudine (89%). HIV-1 RNA was monitored during the first 28 days after treatment initiation. Phase 1 and 2 decay rate was estimated in a subset of 157 patients by RNA decrease from days 0 to 7, and days 14 to 28. One-way ANOVA and subsequent Tukey's post hoc tests were used for groupwise comparisons. Mean (95% CI) HIV-1 RNA reductions from days 0 to 28 were 2.59 (2.45-2.73), 2.42 (2.27-2.57), and 2.13 (2.01-2.25) log(10) copies/ml for the EFV-, LPV/r-, and ATV/r-based treatment groups, respectively, with a significantly larger decrease in the EFV-based group at all time points compared with ATV/r (p < 0.0001), and with LPV/r at days 7-21 (p < 0.0001-0.03). LPV/r gave a greater RNA decrease compared with ATV/r from day 14 (p = 0.02). Phase 1 decay rate was significantly higher in the EFV group compared with LPV/r (p = 0.003) or ATV/r (p < 0.0001). No difference was found in phase 2 decrease. EFV-based treatment gave a more rapid decline in HIV-1 RNA than did either of the boosted protease inhibitor-based regimens. The observed differences may reflect different inherent regimen potencies.
authors.affiliation: Department of Infectious Diseases, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden. arvid.eden@vgregion.se
authors.forename: Arvid
authors.initials: A
authors.lastname: Edén
authors.forename: Lars-Magnus
authors.initials: LM
authors.lastname: Andersson
authors.forename: Orjan
authors.initials: O
authors.lastname: Andersson
authors.forename: Leo
authors.initials: L
authors.lastname: Flamholc
authors.forename: Filip
authors.initials: F
authors.lastname: Josephson
authors.forename: Staffan
authors.initials: S
authors.lastname: Nilsson
authors.forename: Vidar
authors.initials: V
authors.lastname: Ormaasen
authors.forename: Veronica
authors.initials: V
authors.lastname: Svedhem
authors.forename: Christer
authors.initials: C
authors.lastname: Säll
authors.forename: Anders
authors.initials: A
authors.lastname: Sönnerborg
authors.forename: Petra
authors.initials: P
authors.lastname: Tunbäck
authors.forename: Magnus
authors.initials: M
authors.lastname: Gisslén
mesh_terms: D000328:Adult; D000368:Aged; D000480:Alkynes; D019380:Anti-HIV Agents / Q000494:pharmacology / Q000627:therapeutic use; D000069446:Atazanavir Sulfate; D048588:Benzoxazines / Q000494:pharmacology / Q000627:therapeutic use; D003521:Cyclopropanes; D004359:Drug Therapy, Combination; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D061466:Lopinavir; D008297:Male; D008875:Middle Aged; D009842:Oligopeptides / Q000494:pharmacology / Q000627:therapeutic use; D011725:Pyridines / Q000494:pharmacology / Q000627:therapeutic use; D011744:Pyrimidinones / Q000494:pharmacology / Q000627:therapeutic use; D012367:RNA, Viral / Q000097:blood / Q000187:drug effects*; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D000480:Alkynes; D019380:Anti-HIV Agents; D048588:Benzoxazines; D003521:Cyclopropanes; D009842:Oligopeptides; D011725:Pyridines; D011744:Pyrimidinones; D012367:RNA, Viral; D018894:Reverse Transcriptase Inhibitors; D061466:Lopinavir; D000069446:Atazanavir Sulfate; C098320:efavirenz