Background: Currently, data on the effectiveness of second-line antiretroviral regimens using indinavir/ritonavir (IDV/r) and atazanavir/ritonavir (ATV/r) along with 2 nucleoside reverse transcriptase inhibitor (NRTI) in resource-poor settings is limited.
Methods: Observational follow-up study on 441 patients who experienced treatment failure to first-line nonnucleoside reverse transcriptase inhibitor (NNRTI)-based treatment. Multivariate Cox Proportional Hazards Model was used to assess comparative effectiveness of treatment regimens.
Results: A total of 63 patients (14.8%) had failed second line treatments, of which 53 patients (17.2%) were using IDV/r while 10 patients (8.5%) were on ATV/r. After adjusting for age, weight, gender, and baseline CD4 count, patients who took IDV/r were more than twice as likely to experience treatment failure as compared to those who were on ATV/r (hazard ratio [HR] 2.18; 95% confidence interval [CI] 1.14, 4.15). Successful response to second-line therapy was not different between the 2 treatment groups when patients weighed less than 55 kg at baseline (log rank P value = 1.00) in contrast to the individuals weighing ≥55 kg (P < .0001).
Conclusion: We found that successful response to second-line therapy was twice as likely in the ATV/r group; however, this difference was eliminated in patients less than 55 kg.