Lopinavir Plus Ritonavir Limits HIV Drug Resistance

NEW YORK (Reuters Health) - In certain HIV patients, the protease inhibitor lopinavir with ritonavir leads to significantly less drug resistance than does use of nelfinavir, researchers report in the January 1st issue of the Journal of Infectious Diseases.

Dr. Dale J. Kempf and colleagues from Abbott Laboratories, Abbott Park, Illinois examined data from a double-blind study of 635 antiretroviral-naive HIV patients. They were randomized to receive, in addition to stavudine and lamivudine, lopinavir boosted with ritonavir or nelfinavir alone.

Baseline and rebound viral isolates from participants with HIV RNA above 400 copies per mL at weeks 24 to 108 were analyzed to determine HIV drug resistance.

In the 51 lopinavir plus ritonavir patients with available genotypes, no evidence of genotypic or phenotypic resistance was seen.

However, primary mutations related to nelfinavir resistance were detected in 43 of 96 nelfinavir-treated subjects. Furthermore, resistance to lamivudine and stavudine was also significantly higher in the nelfinavir-treated patients.

Thus, the researchers conclude that the findings "clearly demonstrate that a single drug within a combination antiretroviral regime can profoundly affect the likelihood of resistance development to all the drugs in the regimen."

These differences, they add, "may have implications for strategies for initiating antiretroviral therapy."

Source: J Infect Dis 2004;189:51-60. [ Google search on this article ]

MeSH Headings: Biological Phenomena : Biological Phenomena, Cell Phenomena, and Immunity : Biological Sciences : Biology : Drug Resistance, Microbial : Genetics : Genetics, Microbial : Microbiologic Phenomena : Pharmacogenetics : Biological Sciences