A comparison between abacavir and efavirenz as the third drug used in combination with a background therapy regimen of 2 nucleoside reverse-transcriptase inhibitors in patients with initially suppressed viral loads

Alessandro Cozzi-Lepri, Andrea De Luca, Andrew N. Phillips, Marco Bongiovanni, Simona Di Giambenedetto, Maurizio Mena, Maria Cristina Moioli, Massimo Arlotti, Laura Sighinolfi, Pasquale Narciso, Miriam Lichtner, Roberto Cauda, Antonella D'Arminio Monforte

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Abstract

Background. Our objective was to compare the rate of viral rebound and therapy failure in patients receiving abacavir or efavirenz as the third drug (in addition to 2 non-abacavir nucleosides) in combination antiretroviral therapy (cART) and to compare the rate of metabolic alteration associated with these regimens. Methods. We conducted a multicohort prospective observational study of human immunodeficiency virus-infected patients who had attained viral loads ≤80 copies/mL while receiving cART, without having previously received antiretrovirals. The rates of virological rebound, therapy failure, and lipid-level alteration during follow-up were calculated as the number of events divided by person-years of follow-up (PYFU). A multivariable analysis was performed using a Poisson regression model. Results. We studied a total of 744 patients; the median age was 37 years, 27% of the patients were female, and 41% were heterosexual. There was a total of 854 PYFU spent receiving efavirenz and 285 spent receiving abacavir. The nucleoside reverse-transcriptase inhibitor pairs most frequently used were zidovudine/lamivudine (66% of PYFU), stavudine/lamivudine (17.6%), and stavudine/didanosine (5.4%). The adjusted relative rates of virological failure and therapy failure for abacavir, compared with those for efavirenz, were 2.17 (95% confidence interval [CI], 1.12-4.18; P = .02) and 1.41 (95% CI, 1.01-2.01; P = .05), respectively. Conclusions. Patients with virological suppression while receiving regimens containing abacavir appear more likely to experience virological and therapy failure than those receiving efavirenz as their third drug. Although this is a selected group of adherent patients, bias cannot be ruled out, because this is a nonrandomized comparison.

Original languageEnglish
Pages (from-to)20-28
Number of pages9
JournalJournal of Infectious Diseases
Volume194
Issue number1
DOIs
Publication statusPublished - Jul 1 2006

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ASJC Scopus subject areas

  • Public Health, Environmental and Occupational Health
  • Immunology

Cite this

Cozzi-Lepri, A., De Luca, A., Phillips, A. N., Bongiovanni, M., Di Giambenedetto, S., Mena, M., Moioli, M. C., Arlotti, M., Sighinolfi, L., Narciso, P., Lichtner, M., Cauda, R., & D'Arminio Monforte, A. (2006). A comparison between abacavir and efavirenz as the third drug used in combination with a background therapy regimen of 2 nucleoside reverse-transcriptase inhibitors in patients with initially suppressed viral loads. Journal of Infectious Diseases, 194(1), 20-28. https://doi.org/10.1086/504265