Safety Of Abacavir Research Articles

Effectiveness and Safety of Abacavir, Lamivudine, and Zidovudine in Antiretroviral Therapy-Naive HIV-Infected Patients

To analyze the safety and effectiveness of abacavir, lamivudine, and zidovudine (ABC/3TC/ZDV) in antiretroviral therapy (ART)-naive HIV-infected patients. Retrospective observational cohort study. 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. 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). 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.

Antiretroviral Activity and Safety of Abacavir in Combination with Selected HIV-1 Protease Inhibitors in Therapy-Naive HIV-1-Infected Adults

To assess antiretroviral efficacy and safety of abacavir in combination with selected HIV-1 protease inhibitors. A 48-week, open-label study. Eighty-two antiretroviral naive HIV-1-infected adults (CD4 cell count > or = 100 cells/mm3, plasma HIV-1 RNA > or = 5,000 copies/ml) were randomly assigned to receive abacavir (300 mg twice daily) in combination with standard doses of one of five protease inhibitors: indinavir, saquinavir soft-gel, ritonavir, nelfinavir or amprenavir. Adults who met protocol-defined switch criteria at or after week 8 could modify their randomized therapy. Antiretroviral activity was assessed by the proportion of subjects with plasma HIV-1 RNA < or = 400 and < or = 50 copies/ml, and by changes in plasma HIV-1 RNA levels and CD4 cell counts. Safety was assessed by monitoring clinical adverse events and laboratory abnormalities. At week 48, the proportion of subjects in the indinavir, saquinavir, ritonavir, nelfinavir and amprenavir groups with plasma HIV-1 RNA < or = 400 copies/ml was 53, 50, 50, 41 and 56%, respectively, and the proportion with HIV-1 RNA < or = 50 copies/ml was 47, 56, 50, 47, and 44%, respectively (by intent-to-treat analysis). Median reductions from baseline in plasma HIV-1 RNA for each group ranged from 1.7 to 2.4 log10 copies/ml. The median CD4 cell count increase from baseline was 195, 131, 116, 136 and 259 cells/mm3 in the indinavir, saquinavir, ritonavir, nelfinavir, and amprenavir groups, respectively. Overall, the most common adverse events attributed to study drugs were diarrhoea, nausea, malaise/fatigue, headache and perioral paresthesia. The frequency of treatment-limiting adverse events did not differ between groups. Abacavir is safe and effective when used in combination with a protease inhibitor.