Switch to Efavirenz in a Protease Inhibitor-Containing Regimen

Abstract

This report evaluated the efficacy and safety of switching from a protease inhibitor (PI)-containing HIV treatment regimen to an efavirenz (EFV)-containing regimen. We retrospectively analyzed data from 64 patients, with a plasma viral load (VL) less than 50 copies/mL and CD4+ counts >200 cells/mL at baseline, who had been taking a regimen consisting of a PI and two nucleoside reverse transcriptase inhibitors (NRTIs; d4T/3TC [n = 45]; AZT/3TC [n = 19]) for a median of 27.5 months (range, 6-41 months) and who chose to substitute EFV for the PIs in the regimens. Statistical analyses were performed by Wilcoxon test. Fat atrophy was evaluated by physician's assessment and patients' subjective self-estimation with the criteria of well being and body state. 57 patients completed 36 weeks on the EFV regimen; 4 patients changed therapy but continued EFV, 2 moved to another area, and 1 discontinued EFV. During the first weeks of therapy, 56.3% of patients suffered from moderate nervous system symptoms. The plasma VL of 63 patients remained at <50 copies/mL at final analysis. Compared with time of switching to EFV, analysis at 36 weeks showed no statistically significant change from 626+/-283 to 643+/-296 cells/mL in mean absolute CD4+ cells and a statistically significant increase from 26.8+/-9.6% to 28.0+/-9.1% in relative CD4+ cells. There was a statistically significant reduction in relative CD8+CD38+ from 62.2+/-16.3% at time of switching to EFV to 55.1+/-15.0% at week 36. At baseline, 27 patients suffered from lipodystrophy, including fat atrophy and fat accumulation. After 36 weeks, nine patients showed intensified fat atrophy. In contrast, five patients improved their state concerning fat redistribution and 13 patients showed no alterations. The switch to a non-PI-containing regimen with EFV offers a good drug alternative for patients with suppressed viral load, problems of adherence, and/or adverse events due to PIs but not for patients suffering from lipoatrophy caused by nucleoside reverse transcriptase inhibitors. The intention of such a switch aims at the avoidance of fatal mutations in HIV.