The ideal nucleoside/nucleotide backbone.

The selection of the nucleoside/nucleotide reverse transcriptase inhibitor (NRTI/NtRTI) backbone is an important step in constructing a regimen for the treatment of HIV infection. No single NRTI/NtRTI backbone has attributes that make it ideal for every patient, but each has its advantages. Data from clinical trials provide needed guidance on backbone selection and the choice of a 3rd agent to complete a highly active antiretroviral therapy (HAART) regimen. This article reviews available data published since 2000 that address NRTI/NtRTI backbone performance and safety when included in HAART regimens. Based on these trials, the characteristics of different options are compared with an ideal backbone and put into context with other considerations for successful regimen selection and improved outcomes in treatment-naive patients. Practical strategies are offered for implementing contemporary regimens in settings outside clinical trials.