DURHAM, N.C., July 14 (UPI) -- An analysis of 100 HIV patients shows drug resistance from a common antiretroviral treatment regimen is uncommon, U.S. researchers said Wednesday.
Researchers led by a Duke University physician analyzed patients treated with lopinavir and ritonavir, one of the most frequently prescribed protease inhibitor combos that prevents HIV replication by blocking an enzyme. Other drugs used were stavudine and lamivudine, nucleoside reverse transcriptase inhibitors that also block HIV replication.
After five years, 64 percent of participants had undetectable HIV levels in their blood and 27 percent had low-level viral rebound, meaning the virus rose to detectable levels, said the researchers, who presented their findings at the XV International AIDS Conference in Bangkok.
Researchers conducted genetic testing of HIV drug resistance in 17 of rebound patients and found there was no resistance to lopinavir or stavudine and resistance to lamivudine was uncommon.
HIV is difficult to fight because it rapidly develops resistance at low levels of exposure to anti-HIV drugs. About half of people with HIV in the United States have some resistance, said Dr. Charles Hicks, the study's lead author and a consultant for Abbott Laboratories, which funded the study.
