Comparing Different Antiretroviral Combination Therapies
Atriple-combination therapy that includes the antiretroviral drug efavirenz isthe most effective among two other widely used antiretroviral regimens atsuppressing HIV viral loads for initial treatment of HIV-1 infection, accordingto a study published in the May 15 issue of the New England Journal ofMedicine, the Pittsburgh Tribune-Review reports.
For the study, Sharon Riddler, associate professor of medicine at theUniversity of Pittsburgh School ofMedicine, andcolleagues compared the efficacy of three antiretroviral drug combinationsamong 753 people enrolled in NIH's AIDS Clinical Trials Group at 55 centers(Heinrichs, Pittsburgh Tribune-Review, 5/15).
Researchers found that at week 96 of the study, 89% of the participants takingthe combination of efavirenz and two nucleoside reverse transcriptaseinhibitors had less than 50 copies of HIV per milliliter of blood; 77% of thosetaking the combination lopinavir/ritonavir and two NRTIs had less than 50copies; and 83% taking a combination of efavirenz and lopinavir/ritonavir withoutNRTIs -- called NRTI-sparing therapy -- had less than 50 copies. They alsofound that at a median follow-up of 112 weeks, the time to virologic failurewas longer for those in the efavirenz group than for those in thelopinavir/ritonavir group. However, the time to virologic failure was notsignificantly different in the NRTI-sparing group compared with the other twogroups. In addition, the researchers noted that the NRTI-sparing therapy wasnearly as effective as the efavirenz treatment but "was more likely to beassociated with drug resistance" (Riddler et al., NEJM,5/15).
"What we found is that one regimen performs the best, but all of them workpretty well," Riddler said. She added that because people have differentreactions to the drugs and because pregnant women should not take efavirenz,doctors need a variety of alternatives. Drug side effects can includecardiovascular disease, fatigue, and kidney and liver problems, the Tribune-Reviewreports. Riddler added that it is important for people to take the drugsconsistently to prevent resistance.
John Mellors, director of the HIV/AIDS program at UP's Medical Centerand senior co-author of the study, said that the findings offer researchers whoare working to develop more effective antiretrovirals a drug regimen to comparewith other treatments.
"This is a critically important study," Joel Gallant -- a professorat the Johns Hopkins University School of Medicine, who did not participate in the study -- said. The research "really compares what have been considered the gold standards" of treatment, he added (Pittsburgh Tribune-Review, 5/15).
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