Rate of viral rebound according to specific drugs in the regimen in 2120 patients with HIV suppression.
BACKGROUND
It is currently unclear whether the tendency for viral rebound in patients with viral load < 50 copies/ml differs according to the specific drug regimen being used.


METHODS
To follow 2120 patients in EuroSIDA who had attained < 50 copies/ml on highly active antiretroviral therapy (HAART), without previously virologically failing HAART.


RESULTS
The rate of viral rebound (two consecutive values > 400 copies/ml) was 4.9/100 person-years [95% confidence interval (CI), 4.0-5.8] for patients who were naive pre-HAART and 8.0/100 person-years (95% CI, 7.0-9.0) for those who were experienced with nucleoside analogue reverse transcriptase inhibitors (NRTI) pre-HAART. The rate of rebound was significantly higher in those taking nelfinavir than in those taking efavirenz, both in patients who were naive pre-HAART and those who were NRTI experienced [adjusted rate ratios, 2.83 (95% CI, 1.51-5.31) and 2.86 (95% CI, 1.65-5.00), respectively]. Among patients who were naive pre-HAART, those on abacavir had no evidence of a raised risk of viral rebound (adjusted rate ratio 1.17; 95% CI, 0.51-2.69), but in those with pre-HAART NRTI experience the rate was markedly raised (adjusted rate ratio, 4.48; 95% CI, 2.51-8.00). A similar picture was seen when comparing those on nevirapine with those on efavirenz, although the elevated rate ratio in pre-HAART experienced patients was of lower magnitude (adjusted rate ratio, 1.93). There was no strong evidence that rebound rates differed significantly for any NRTI pairs compared with zidovudine/lamivudine.


CONCLUSIONS
Viral rebound rates in patients who have attained < 50 copies/ml appear to differ according to the specific drugs being used.
Royal Free Centre for HIV Medicine, Department of Primary Care and Population Sciences, Royal Free and University College Medical School, London, UK.
Andrew N
AN
Phillips
Bruno
B
Ledergerber
Andrezej
A
Horban
Peter
P
Reiss
Antonio
A
Chiesi
Ole
O
Kirk
Fiona
F
Mulchany
Martin
M
Fisher
Ladislav
L
Machala
Jens D
JD
Lundgren
D000328:Adult; D000480:Alkynes; D023241:Antiretroviral Therapy, Highly Active; D048588:Benzoxazines; D015331:Cohort Studies; D003521:Cyclopropanes; D015224:Dideoxynucleosides / Q000627:therapeutic use; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D006801:Humans; D008297:Male; D019888:Nelfinavir / Q000627:therapeutic use; D019829:Nevirapine / Q000627:therapeutic use; D010078:Oxazines / Q000627:therapeutic use; D011446:Prospective Studies; D019562:Viral Load; D000099227:Abacavir
D000480:Alkynes; D048588:Benzoxazines; D003521:Cyclopropanes; D015224:Dideoxynucleosides; D019888:Nelfinavir; D019829:Nevirapine; D010078:Oxazines; D000099227:Abacavir; C098320:efavirenz