Background: Mild neurocognitive impairment is thought to be relatively common in HIV infection, but the reasons are not fully understood. In patients on stable suppressive anti-retroviral therapy (ART) it is unclear whether modification of ART can have any beneficial effects on neurocognitive function. Specifically recent cross-sectional data have suggested that efavirenz (EFV) may be associated with mild neurocognitive impairment. Our aim was therefore to explore whether neurocognitive function and brain metabolites are improved by switching away from EFV.
Methods: We performed an open label phase IV study in HIV-infected adults on suppressive HAART containing EFV. All subjects were switched from EFV to ritonavir-boosted lopinavir (LPV/r, Kaletra). Nucleoside/nucleotide backbone drugs were continued. Observations were performed before and 10 weeks after ART switch. Primary outcome measure was change in neurocognitive performance (by CogState computerised battery). Secondary outcome measures were change in cerebral metabolites (by proton magnetic resonance spectroscopy, 1 H-MRS), tasked-based (attentional processing) functional magnetic resonance imaging (fMRI), and change in sleep parameters.
Results: 17 subjects entered the study and 16 completed. No changes were observed in any measures of neurocognitive performance, cerebral metabolites, or on task-based fMRI. There was improvement in sleep quality (mean change in PSQI (Pittsburgh Sleep Quality Index), -3.4; 95% CI, -6.0 to -0.7).
Conclusions: EFV is unlikely to be a major modifiable contributor to neurocognitive function in stable HIV-infected persons on suppressive HAART.