Adherence to antiretroviral therapy and outcomes in HIV-infected patients enrolled in an induction/maintenance randomized trial.
OBJECTIVE
To examine the effect of adherence to therapy on early virological response, later virological failure, and occurrence of adverse events in HIV-infected patients.


METHODS
A randomized trial of 3-month induction period of zidovudine/lamivudine/indinavir followed by a maintenance phase of zidovudine/lamivudine/indinavir, zidovudine/lamivudine or zidovudine/indinavir.


RESULTS
Adherence was assessed by pill count. In the induction phase, early virological response was defined as plasma HIV-RNA<500 copies/ml at month 2 and in the maintenance phase, virological failure was defined as plasma HIV-RNA >500 copies/ml in two consecutive specimens.


RESULTS
The median adherence rate was 97% in both induction (n=366) and maintenance phase (n=237). In the maintenance phase, pairwise comparisons showed a lower adherence rate in zidovudine/lamivudine/indinavir versus zidovudine/lamivudine (P=0.03), or versus zidovudine/indinavir (P=0.05). Only 13% of patients had an adherence over the maintenance phase of 80% or lower, while 40% of patients occasionally had an adherence rate of 80% or lower during this phase. Among the 362 patients with documented HIV-RNA at month 2, 86% had an early virological response. Adherence of 80% or greater was the only variable statistically predictive to early virological response (P<0.001), while baseline CD4, baseline HIV-RNA, and adherence of 95% or greater were not associated to virological response. In the maintenance phase, adherence, baseline HIV-RNA, HIV-RNA at month 3 and treatment groups were independently predictive to time to virological failure. Analysis by randomized groups indicated that difficulty in adherence (<80%) was predictive to time to failure (P<0.001) only in both indinavir-containing regimens. Occurrence of two or more severe adverse events (grade 3 and 4) was higher in patients with poor adherence although not statistically associated (P=0.12), while no association was found with minor adverse events.


CONCLUSIONS
Adherence rate was globally lower in patients maintaining the original triple-drug therapy compared with those receiving less intensive regimens. Adherence rate was a time-dependent variable. Adherence to antiviral regimen of 80% or greater was predictive to early virological response, and adherence rate lower than 80% or 95% was predictive to virological failure, especially in indinavir-containing regimens. Occurrence of adverse events was not clearly associated to adherence.
Flandre
Philippe
P
INSERM SC10, Hĵpital Paul Brousse, Villejuif, France. p.flandre@vjf.inserm.fr
Peytavin
Gilles
G
Meiffredy
Vincent
V
Saidi
Yacine
Y
Descamps
Diane
D
Delagnes
Martine
M
Brun-Vézinet
Françoise
F
Raffi
François
F
D000328:Adult; D019380:Anti-HIV Agents / Q000009:adverse effects / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D017320:HIV Protease Inhibitors / Q000627:therapeutic use; D006801:Humans; D019469:Indinavir / Q000627:therapeutic use; D019259:Lamivudine / Q000627:therapeutic use; D008297:Male; D010349:Patient Compliance; D012367:RNA, Viral / Q000032:analysis; D016896:Treatment Outcome; D015215:Zidovudine / Q000627:therapeutic use
D019380:Anti-HIV Agents; D017320:HIV Protease Inhibitors; D012367:RNA, Viral; D019259:Lamivudine; D015215:Zidovudine; D019469:Indinavir