Objective: To analyse the safety and efficacy of replacing the protease inhibitor (PI) by nevirapine (NVP) in subjects experiencing a long-term control of virus replication under a triple PI-containing antiretroviral combination.
Design: Prospective evaluation of 138 HIV-positive subjects with plasma viral load below 50 HIV-RNA copies/ml for the last 6 months under a triple PI-containing regimen, who were randomly assigned to either replace the PI by NVP (n = 104) or continue on the same treatment (n = 34).
Methods: Viral load, CD4 count, lipid profile, body-shape features, and quality of life parameters were all assessed at the time of randomization and every 3 months thereafter.
Results: In an intent-to-treat analysis, a rebound in viral load occurred in 11% of subjects during the first 6 months after replacing the PI by NVP, whereas it appeared in 29% of those who remained on PI (P = 0.007). Treatment failure was related to lack of adherence in 90% of subjects on PI, but only in 22% of those receiving NVP (P = 0.006). The CD4 cell count outcome did not differ significantly comparing both groups at 6 months, although in patients receiving NVP an average reduction of 35 x 10(6) cells/l was observed, whereas in those on PI a positive trend was still recorded (+54 x 10(6) cells/l). At the time of randomization, 77.5 and 57.5% of subjects had cholesterol and triglyceride values above 200 mg/dl, respectively. No significant changes in the lipid profile were observed in any of the groups thereafter. Body-shape abnormalities were recorded in 70% of persons at the time of randomization, and partially reversed at 6 months in 50% of subjects who replaced the PI by NVP. A quality of life score recorded a significant improvement in subjects who switched to NVP compared with those who continued on PI.
Conclusions: The replacement of PI by NVP seems to be safe both virologically and immunologically, provides a significant improvement in the quality of life and in half of patients ameliorate lipodystrophic body-shape changes at 6 months, although serum lipid abnormalities still remain unmodified.