American Board of Internal Medicine (ABIM) Certification Practice Exam

What does the backbone of antiretroviral therapy for HIV typically include?

1. Two nonnucleoside reverse transcriptase inhibitors

2. Two nucleoside/nucleotide reverse transcriptase inhibitors plus a third agent

3. A single integrase inhibitor

4. Three protease inhibitors

The correct answer is: Two nucleoside/nucleotide reverse transcriptase inhibitors plus a third agent

The backbone of antiretroviral therapy for HIV typically includes two nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) combined with a third active agent, which may be from a different drug class such as a nonnucleoside reverse transcriptase inhibitor (NNRTI), a protease inhibitor (PI), or an integrase strand transfer inhibitor (INSTI). This combination is preferred as it provides potent suppression of the virus while allowing for synergistic effects from the various classes of medications. Using two NRTIs helps to reduce the viral load effectively while minimizing the potential for resistance development, which is critical in managing HIV infection. The third agent serves to further enhance the effectiveness of the regimen by targeting the virus through a different mechanism of action, thus providing a more robust defense against the virus. Other options, while they include valid components of HIV treatment, do not reflect the standard guideline-recommended approach for the initial therapy of HIV infection. For instance, a regimen consisting solely of two nonnucleoside reverse transcriptase inhibitors lacks the necessary variety to prevent resistance and may not provide sufficient viral suppression. A single integrase inhibitor, while effective, does not represent a complete backbone regimen on its own. Lastly, relying