ABSTRACT
Ritonavir is a potent, orally bioavailable inhibitor of HIV-1 protease. Our investigatiors underlook a retrospective study to compare the effectiveness of ritonavir (600 mg twice daily) associated with 2 reverse transcriptase inhibitors (RTIs) in 38 patients in 3 situations. Group I - patients previously treated with 2 RTIs, Group II - treatment-naive patients, and Group III - patients previously treated with 2 RTIs and saquinavir. Routine hematological and biochemical studies, HIV-1 viremia, and CD4 lymphocyte counts were performed before and after ritonavir. In group I, the median of HIV-1 RNA plasma levels decreased from 4.8 to 3.4 log10 copies/mL, in Group II from 5.9 to 2.9 log10 copies/mL, and in Group III from 5.2 to 4.1 log10 copies/mL (p=0.003, p=0.002, respectively, Wilcoxon signed rank test). The median increases of CD4+ cells occurred as follows: in Group I from 173 to 282 cells/mm3, in Group II from 92 to 254 cell/mm3, and in Group III from 68 to 133 cell/mm3(p=0.002, p=0.008, p<0.001, respectively, Wilcoxon signed rank test) In group II the mean weight increased from 55.2+14.3 kg to 59.4+15.7 kg and, in Group III, from 62.2+10.5 kg to 67.5+12 kg (p=0.026, p=0.002, respectively, paired T test). Patients in Group I presented no weight gain. Mild reversible hypertriglyceridemia occurred in 6 of 38 patients. The results of this study showed that ritonavir is a good choice for treatment naive patients and as a sequential option, not only after 2 RTIs, but also after a 3 drug regimen with saquinavir.