Ritonavir-boosted HIV protease inhibitors in first-line antiretroviral therapy regimens

The efficiency and safety of antiretroviral therapy (ART) regimens based on ritonavir-boosted HIV protease inhibitors (PIs) were studied in 102 patients with HIV infection. Following 24-week therapy, 65-90% of patients showed a reduction in HIV RNA levels below the threshold of detection by a test system. In the first 6 months of therapy, the increment in the CD4 lymphocyte count was 60-130 cells/μl. The ART regimens comprising ritonavir-boosted PIs were also highly effective in patients with a high baseline HIV RNA level (more than 100000 copies/ml) or a low CD4 lymphocyte count (less than 200 cells/μl). The use of ritonavir-boosted PIs was safe in the absolute majority of patients. The most common adverse reactions were lopinavir/ritonavir-induced diarrhea and atazanavir/ritonavir-induced icteric coloration of the skin and sclerae. In most cases, these were mild and transient. Despite the fact that 65-80% of the patients included into the study were diagnosed as having chronic hepatitis C and before ART 25-29.4% of the patients were recorded to have elevated ALT levels, the use of ritonavir-boosted PIs was safe in the absolute number of patients. In 76-84%% of the patients, adherence to ART was greater than 95%; a half of the patients with incomplete therapy adherence were observed to have lower HIV RNA levels below the threshold of detection by a test system, which is likely to be caused by the improved pharmacokinetics of ritonavir-boosted PIs, with their use the treatment was effective even during incomplete adherence.