Purpose: To compare outcomes of nonnucleoside reverse transcriptase inhibitors (NNRTIs) nevirapine or efavirenz versus abacavir-based regimens with a backbone of zidovudine and lamivudine as initial therapy of treatment-naive adults with HIV-1 infection in routine clinical care.
Method: All patients starting their first antiretroviral therapy with any of the studied regimens from January 1999 to December 2002 were included in the analysis. Rates of viral suppression (HIV-RNA below 50 copies/mL) and discontinuation of any component of the regimen were compared at 48 weeks.
Results: Fifty-one patients started with one of the two NNRTI-based regimens and 49 started with the triple nucleoside regimen (3-NRTI). After 48 weeks, more patients in the NNRTI regimens (76.5%) than in the 3-NRTI (51.1%) regimen achieved a HIV-1 RNA level below the limit of detection (<1.7 log10 copies/mL; p = .008). Time to change the antiretroviral regimen was shorter with 3-NRTI (median [range]: 234 [139-329] days) than with NNRTI (346 [0-756] days) (p = .0901). More withdrawals related to drug toxicity or intolerance occurred with the 3-NRTI-based regimen.
Conclusion: In a routine clinical care setting, initial antiretroviral treatment with an NNRTI (nevirapine or efavirenz) plus zidovudine and lamivudine was virologically superior and safer than a 3-NRTI therapy (abacavir with the same NRTI backbone).