Efficacy and safety of ritonavir-boosted and unboosted atazanavir among antiretroviral-naïve patients.
OBJECTIVE
Evaluate responses and safety of ritonavir-boosted atazanavir ("boosted atazanavir") compared to unboosted atazanavir among antiretroviral-naïve patients in the clinical managed care setting.


METHODS
Observational cohort analysis of atazanavir use (comparing ritonavir-boosted to non-boosted) at Kaiser Permanente and Group Health Cooperative from 2003 to 2006. Antiretroviral-naïve patients initiating atazanavir were followed through 52 weeks of treatment.


RESULTS
443 patients were prescribed atazanavir (69 non-boosted; 15.5%). Boosted and non-boosted atazanavir groups were similar with respect to gender and age. Boosted atazanavir use was associated with greater odds achieving HIV RNA <400 c/mL (odds ratio [OR] = 3.24, p = .008), greater decrease in HIV RNA (-0.37 log10/mL, p = .03), greater increase in CD4 T-cell count (+59 cells/microL, p = .01), and greater increase in total bilirubin (+1.21 mg/dL as opposed to +0.56 mg/dL, p .001). There were no statistically significant differences for glucose, liver transaminases, total cholesterol, or LDL cholesterol elevations. There were greater odds of maximal viral control when atazanavir was combined with tenofovir or zidovudine in combination with lamivudine (or emtricitabine).


CONCLUSIONS
Ritonavir-boosted atazanavir is associated with greater virologic control and immune response through 52 weeks compared to non-boosted atazanavir, without greater risk of adverse events except elevated bilirubin. Thus, ritonavir-boosted atazanavir is the preferred method of prescribing atazanavir.
Horberg
Michael
M
HIV Initiative, Kaiser Permanente, Oakland, California 94612, USA. michael.horberg@kp.org
Klein
Daniel
D
Hurley
Leo
L
Silverberg
Michael
M
Towner
William
W
Antoniskis
Diana
D
Kovach
Drew
D
Mogyoros
Miguel
M
Blake
William
W
Dobrinich
Robert
R
Dodge
Wayne
W
D000328:Adult; D019380:Anti-HIV Agents / Q000009:adverse effects / Q000627:therapeutic use; D000069446:Atazanavir Sulfate; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D004359:Drug Therapy, Combination; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D017320:HIV Protease Inhibitors / Q000009:adverse effects / Q000627:therapeutic use; D015497:HIV-1 / Q000187:drug effects* / Q000502:physiology; D006279:Health Maintenance Organizations; D006801:Humans; D008297:Male; D008875:Middle Aged; D009842:Oligopeptides / Q000009:adverse effects / Q000627:therapeutic use; D011725:Pyridines / Q000009:adverse effects / Q000627:therapeutic use; D012367:RNA, Viral / Q000097:blood; D018894:Reverse Transcriptase Inhibitors / Q000009:adverse effects / Q000627:therapeutic use; D019438:Ritonavir / Q000009:adverse effects / Q000627:therapeutic use; D016896:Treatment Outcome
D019380:Anti-HIV Agents; D017320:HIV Protease Inhibitors; D009842:Oligopeptides; D011725:Pyridines; D012367:RNA, Viral; D018894:Reverse Transcriptase Inhibitors; D000069446:Atazanavir Sulfate; D019438:Ritonavir