title: Quadruple nucleoside therapy with zidovudine, lamivudine, abacavir and tenofovir in the treatment of HIV.
abstract: Highly active antiretroviral therapy (HAART) has significantly reduced morbidity and mortality in HIV-infected patients. However, problems such as short-term or long-term toxicity and the development of drug resistance could necessitate a change in the therapy regimen. Whereas various HAART options with low pill burden and favourable long-term tolerability profiles are available for naive patients, treatment of experienced patients tends to be more complex and remains a challenge. Treatment with class sparing nucleoside-only regimens could be an option in this context, but the combination of zidovudine (AZT), lamivudine (3TC) and abacavir (ABC) has shown to be inferior in terms of virological efficacy compared with the standard regimen. More promising data were obtained when AZT, 3TC and ABC were intensified with tenofovir (TDF), resulting in a quadruple nucleoside therapy. This regimen has demonstrated comparable potency to a standard regimen with AZT, 3TC and efavirenz in treatmentnaive patients. Additionally, it has shown to be an efficient treatment option especially in moderately pretreated patients. This is accredited to the potency of the single components and the antagonistic selection pressure of AZT and TDF. The presence of L210W, or at least two of the mutations 41L, 67N, 70R, 215F/Y or 219Q/E, at or before baseline seems to be a predictor of non-response, whereas the presence of M184V does not impede virological response and might even be advantageous. This review summarizes current data on the combined use of AZT, 3TC, ABC and TDF in regard to virological and immunological outcome as well as genotypic predictors of response.
authors: JW Goethe University Hospital, Institute for Medical Virology, Paul-Ehrlich-Strasse 40, 60596 Frankfurt, Germany. M.Stuermer@em.uni-frankfurt.de
authors: Martin
authors: M
authors: Stürmer
authors: Schlomo
authors: S
authors: Staszewski
authors: Hans Wilhelm
authors: HW
authors: Doerr
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D019380:Anti-HIV Agents / Q000494:pharmacology / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D015224:Dideoxynucleosides / Q000494:pharmacology / Q000627:therapeutic use*; D024921:Drug Resistance, Multiple, Viral / Q000235:genetics; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D019259:Lamivudine / Q000494:pharmacology / Q000627:therapeutic use*; D009154:Mutation; D063065:Organophosphonates / Q000494:pharmacology / Q000627:therapeutic use*; D017410:Practice Guidelines as Topic; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D000068698:Tenofovir; D017211:Treatment Failure; D016896:Treatment Outcome; D019562:Viral Load; D015215:Zidovudine / Q000494:pharmacology / Q000627:therapeutic use*; D000099227:Abacavir
chemical_list: D000225:Adenine; D019380:Anti-HIV Agents; D015224:Dideoxynucleosides; D019259:Lamivudine; D063065:Organophosphonates; D018894:Reverse Transcriptase Inhibitors; D000068698:Tenofovir; D015215:Zidovudine; D000099227:Abacavir