Tang, Michele W.Kanki, PhyllisShafer, Robert W.2012-05-102012Tang, Michele W., Phyllis J. Kanki, and Robert W. Shafer. 2012. A review of the virological efficacy of the 4 world health organization–recommended tenofovir-containing regimens for initial HIV therapy. Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America 54(6): 862-875.1058-4838http://nrs.harvard.edu/urn-3:HUL.InstRepos:8715418We systematically reviewed studies of the virological efficacy of the 4 new tenofovir (TDF)-containing regimens recommended for initial antiretroviral (ARV) therapy in the 2010 World Health Organization ARV Treatment Guidelines. Thirty-three studies assessed the efficacy of 1 or more TDF-containing regimens: TDF/lamivudine (3TC)/nevirapine (NVP) (n 5 3), TDF/ emtricitabine (FTC)/NVP (n 5 9), TDF/3TC/efavirenz (EFV) (n 5 6), and TDF/FTC/EFV (n 5 19). TDF/3TC/NVP was the least well-studied and appeared the least efficacious of the 4 regimens. In 2 comparative studies, TDF/3TC/NVP was associated with significantly more virological failure than AZT/3TC/NVP; a third study was terminated prematurely because of early virological failure. TDF/FTC/NVP was either equivalent or inferior to its comparator arms. TDF/3TC/EFV was equivalent to its comparator arms. TDF/FTC/EFV was equivalent or superior to its comparator arms. Possible explanations for these findings include the greater antiviral activity of EFV versus NVP and longer intracellular half-life of FTC-triphosphate versus 3TC-triphosphate. Further study of TDF/3TC/NVP is required before it is widely deployed for initial ARV therapy.en-USJournal Article2012-05-1010.1093/cid/cir1034