Effectiveness and safety of abacavir, lamivudine, and zidovudine in antiretroviral therapy-naive HIV-infected patients: results from a large multicenter observational cohort.

OBJECTIVE: To analyze the safety and effectiveness of abacavir, lamivudine, and zidovudine (ABC/3TC/ZDV) in antiretroviral therapy (ART)-naive HIV-infected patients. DESIGN: 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 or = LOQ after achieving a pVL