In an effort to simplify therapy, researchers are testing different combinations and schedules of drugs. One combination being studied is the protease inhibitor (PI) saquinavir (Fortovase, Invirase) with the PI ritonavir (Norvir). This is because ritonavir can boost levels of saquinavir in the blood for a prolonged period of time, extending its anti-HIV activity. This allows for a reduced number of pills that need to be taken daily. The downside of most ritonavir-saquinavir combinations is:
By reducing the dose of ritonavir and increasing the dose of saquinavir, researchers hope to develop a once-daily protease inhibitor regimen using currently licensed drugs. Once-daily regimens may be more convenient for people who have the following issues:
Dr. Julio Montaner and colleagues enrolled 161 HIV positive subjects who had not previously used anti-HIV drugs and who had the following profile:
Researchers randomly assigned subjects to receive one of the following regimens together with two nukes once daily:
The proportion of subjects in each of the following groups who achieved a viral load of fewer than 50 copies in each group was as follows:
This difference between the two groups was statistically significant; that is, not likely due to chance alone. The difference was probably caused by the greater number of subjects in the saquinavir-ritonavir group who left the study because of side effects.
On average, all subjects in the study had an increase of about 150 extra CD4+ cells. The increase was slightly higher for subjects who received saquinavir-ritonavir.
Major side effects in the saquinavir-ritonavir group were as follows:
Changes in lipid levels were minor and similar among the two groups. The number of subjects who left the study because of side effects in each group is as follows:
Dr. Montaner suspects that some of the ingredients in Fortovase (the newer, soft-gel formulation of saquinavir) capsules may be responsible for the nausea and diarrhea reported in the study. He is conducting experiments with the original formulation of saquinavir — Invirase (hard-gel capsule). Preliminary results suggest that Invirase capsules have fewer side effects and are better tolerated when used at a dose of 1,600 mg together with ritonavir 100 mg, both drugs taken once daily. Dr. Montaner also reported that the combination of saquinavir-ritonavir had no significant effect on methadone levels in people using that drug.
REFERENCE
Montaner JSG, Saag M, Barylski C, et al. FOCUS study: saquinavir QD regimen versus efavirenz QD regimen: 24 week analysis in HIV-infected patients. Abstract I-669 - 41st annual Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC),Chicago, 16–19 December 2001.
20020131
CATE12407
Copyright © 2002 - TreatmentUpdate. Reproduced with permission. Reproduction of this article (other than one copy for personal reference) must be cleared through the Editor, The Canadian AIDS Treatment Information Exchange, 555 Richmond St. West, Suite 505, Box 1104, Toronto, ON, M5V 3B1 • Phone: 416-203-7122 • Toll Free: 1-800-263-1638 • Fax: 416-203-8284 http://www.catie.ca.
AEGiS is made possible through unrestricted grants from Boehringer Ingelheim, Elton John AIDS Foundation, iMetrikus, Inc., the National Library of Medicine, and donations from users like you. Always watch for outdated information. This article first appeared in 2002. This material is designed to support, not replace, the relationship that exists between you and your doctor.
AEGiS presents published material, reprinted with permission and neither endorses nor opposes any material. All information contained on this website, including information relating to health conditions, products, and treatments, is for informational purposes only. It is often presented in summary or aggregate form. It is not meant to be a substitute for the advice provided by your own physician or other medical professionals. Always discuss treatment options with a doctor who specializes in treating HIV.
Copyright ©1980, 2002. AEGiS. All materials appearing on AEGiS are protected by copyright as a collective work or compilation under U.S. copyright and other laws and are the property of AEGiS, or the party credited as the provider of the content.