title: Effectiveness and safety of abacavir, lamivudine, and zidovudine in antiretroviral therapy-naive HIV-infected patients: results from a large multicenter observational cohort.
abstract: OBJECTIVE
  To analyze the safety and effectiveness of abacavir, lamivudine, and zidovudine (ABC/3TC/ZDV) in antiretroviral therapy (ART)-naive HIV-infected patients.
  
  
  METHODS
  Retrospective observational cohort study.
  
  
  METHODS
  We analyzed all consecutive ART-naive HIV-infected patients who initiated ABC/3TC/ZDV in 71 centers throughout Spain and had a clinical visit and laboratory data at least 16 weeks after initiating this regimen. We assessed safety, mortality, new AIDS-defining conditions (ADCs) and treatment failure, the latter defined by any of the following: (1) reduction in plasma HIV-1 viral load (pVL) <1 log during the first 12 weeks of ART, unless it was less than the lower limit of quantification (LOQ); (2) failure to achieve a pVL <LOQ after 24 weeks of ART; and (3) rebound to 2 consecutive pVLs > or = LOQ after achieving a pVL <LOQ.
  
  
  RESULTS
  A total of 730 patients were included, median patient age was 37 years, prior ADCs occurred in 20%, median pVL was 4.76 log, and median CD4 count was 255 cells/mm; 109 (14.9%) patients had <100 CD4 cells/mm. After a median follow-up of 50.5 weeks (interquartile ratio: 28-78), 104 (14.25%) patients discontinued therapy because of adverse events and 36 (4.93%) had a suspected hypersensitivity reaction to ABC. The frequency of treatment failure according to an intention-to-treat (ITT) analysis of observed data was 14.4%. In a more rigorous approach considering losses to follow-up and interruptions or switches of therapy as failures, however, the frequency of treatment failure was 22.92%. Factors independently associated with treatment failure by observed data ITT analysis were adherence <90% (hazard ratio [HR] = 4.248, 95% confidence interval [CI]: 2.640 to 6.833), methadone use (HR = 2.116, 95% CI: 1.180 to 3.797), baseline pVL (HR = 1.651, 95% CI: 1.190 to 2.292 per log), and prior ADC (HR = 1.639, 95% CI: 1.009 to 2.662).
  
  
  CONCLUSIONS
  The triple-nucleoside regimen of ABC/3TC/ZDV is a reasonable option for ART-naive patients with a pVL <100,000 copies/mL in whom, for any reason, preferred regimens are not advisable, even in patients with a baseline CD4 cell count <100 cells/mm.
authors.affiliation: Infectious Diseases and HIV Unit, Hospital Gregorio Marañón, Madrid, Spain. juaberber@terra.es
authors.forename: Juan
authors.initials: J
authors.lastname: Berenguer
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: Pérez-Elías
authors.forename: José María
authors.initials: JM
authors.lastname: Bellón
authors.forename: Hernando
authors.initials: H
authors.lastname: Knobel
authors.forename: Pablo
authors.initials: P
authors.lastname: Rivas-González
authors.forename: José María
authors.initials: JM
authors.lastname: Gatell
authors.forename: Máximo
authors.initials: M
authors.lastname: Miguélez
authors.forename: José
authors.initials: J
authors.lastname: Hernández-Quero
authors.forename: Juan
authors.initials: J
authors.lastname: Flores
authors.forename: Vicente
authors.initials: V
authors.lastname: Soriano
authors.forename: Ignacio
authors.initials: I
authors.lastname: Santos
authors.forename: Daniel
authors.initials: D
authors.lastname: Podzamczer
authors.forename: Monserrat
authors.initials: M
authors.lastname: Sala
authors.forename: Manuel
authors.initials: M
authors.lastname: Camba
authors.forename: Salvador
authors.initials: S
authors.lastname: Resino
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000009:adverse effects / Q000627:therapeutic use*; D015331:Cohort Studies; D015224:Dideoxynucleosides / Q000009:adverse effects / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D015497:HIV-1; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology; D019259:Lamivudine / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D010349:Patient Compliance; D012189:Retrospective Studies; D013030:Spain; D017211:Treatment Failure; D015215:Zidovudine / Q000009:adverse effects / Q000627:therapeutic use*; D000099227:Abacavir
chemical_list: D019380:Anti-HIV Agents; D015224:Dideoxynucleosides; D019259:Lamivudine; D015215:Zidovudine; D000099227:Abacavir