Relationship between plasma protease inhibitor concentrations and lipid elevations in HIV patients on a double-boosted protease inhibitor regimen (saquinavir/lopinavir/ritonavir).

The relationship between plasma protease inhibitor (PI) trough concentrations and hyperlipidemic effects were evaluated retrospectively using data from 2 pilot clinical trials of a double-boosted PI regimen (saquinavir/lopinavir/ritonavir) in 25 HIV patients. The patients' median age was 39 years (range, 25-60). At baseline, PI-naive patients had a median viral load of 53 500 copies/mL and median CD4 of 296 cells/mm(3), while PI-experienced patients had 37 750 copies/mL and 214 cells/mm(3). Plasma PI trough concentrations of saquinavir, lopinavir, and ritonavir at week 12 were 520, 4482, and 153 ng/mL, respectively. At week 12, median fasting lipids increased significantly from baseline: total cholesterol increased from 165 to 189 mg/dL (P = .0005) and the triglyceride increased from 113 to 159 mg/dL (P = .001). There were no associations between PI trough concentrations at week 12 and the percent total cholesterol change at week 12. No associations were found between PI trough concentrations and lipid changes in HIV patients on a double-boosted PI regimen (saquinavir/lopinavir/ritonavir). Factors other than systemic exposure to PIs (such as host or genetic factors) may modulate the hyperlipidemic effect of PIs.

Pilot study of saquinavir and lopinavir/ritonavir twice daily in protease inhibitor-naive HIV-positive patients.

PURPOSE: Protease inhibitor (PI)-naive patients may have limited reverse transcriptase inhibitor (RTI) options due to resistance and/or toxicity. Effective, well-tolerated nucleoside reverse transcriptase inhibitor (NRTI)-sparing regimens are therefore needed. METHOD: This prospective study evaluated the efficacy and safety of saquinavir/lopinavir/ritonavir (1000/400/100 mg bid) in PI-naive patients over 48 weeks. The regimen could be intensified with NRTIs if patients did not achieve virologic suppression by 12 weeks. The primary study endpoint was virologic suppression at 48 weeks. Additional study objectives included assessment of safety, CD4 cell counts, blood lipids, PI trough levels, and anthropometrics. RESULTS: Of the 20 PI-naive study participants, 16 completed 48 weeks of study treatment, with no discontinuations attributed to virologic failure. Fourteen of 16 patients achieved virologic suppression with only the PIs; 2 patients required tenofovir intensification to achieve complete suppression. Median CD4 counts increased significantly over 48 weeks. Adverse events were generally mild and manageable. Extreme lipid elevations were uncommon, although moderate lipid elevations occurred in the majority of patients. Most patients reported some degree of central fat accumulation. CONCLUSION: Our study demonstrates that saquinavir/lopinavir/ritonavir 1000/400/100 mg bid with tenofovir intensification is a potent nucleoside-sparing regimen for PI-naive patients, associated with durable HIV suppression and improved CD4 cell counts. Fat accumulation and metabolic changes observed in this study warrant confirmation from ongoing trials.