Saquinavir With Low-Dose Ritonavir Twice Daily

Researchers at several sites in the U.S. recruited 21 HIV positive subjects for this study which compared the effect of two different boosted protease inhibitor (PI) regimens:

• saquinavir (Fortovase) 400 mg with ritonavir (Norvir) 400 mg, both twice daily
• saquinavir 1,000 mg with ritonavir 100 mg, both twice daily

The combinations were taken with two or more other anti-HIV drugs.

The profile of subjects was as follows:

• 3 females, 18 males
• average age: about 40 years
• average CD4+ count ranged between 400 and 700 cells
• average viral load: fewer than 400 copies

Before entering the study, all subjects were taking a combination of saquinavir and ritonavir (saq/rit) at a dose of 400/400 mg twice daily in combination with two or more anti-HIV drugs. Subjects were randomly assigned to receive one of the two above-mentioned PI dose combinations and were monitored for six months.

Results

Three subjects left the study for the following reasons:

• painfully swollen pancreas gland, or pancreatitis (2 males)
• very high levels of cholesterol and triglycerides (1 female)

One subject, who was taking the 400/400-mg regimen had his viral load rise above the 1,000 copy mark during the study.

By the sixth month of the study, more subjects (9) on the 1,000/100 regimen had suppressed their viral load compared to subjects on the 400/400 regimen (6).

Over time, there were trends to lower triglyceride and cholesterol levels in subjects given 1,000/100. CD4+ counts were also higher in that group. As well, the 1,000/100 combination was better tolerated than the combination that included a higher dose of ritonavir. More details about tolerating saquinavir appear in our next CATIE News story: "Invirase vs. Fortovase -- Unexpected Results?"

Reference

1. O'Brien WA, Acosta E, Felizarta F, et al. Switch of saquinavir 400 mg/Ritonavir 400 mg to saquinavir 1,000 mg/Ritonavir 100 mg during BID four drug antiretroviral therapy. 3rd International Workshop on Clinical Pharmacology of HIV Therapy, Washington D.C., 11-13 April, 2002; abstract 2.1.