Viral resuppression and detection of drug resistance following interruption of a suppressive non-nucleoside reverse transcriptase inhibitor-based regimen

AIDS. 2008 Nov 12;22(17):2279-89. doi: 10.1097/QAD.0b013e328311d16f.

Abstract

Background: Interruption of a non-nucleoside reverse transcriptase inhibitor (NNRTI)-regimen is often necessary, but must be performed with caution because NNRTIs have a low genetic barrier to resistance. Limited data exist to guide clinical practice on the best interruption strategy to use.

Methods: Patients in the drug-conservation arm of the Strategies for Management of Antiretroviral Therapy (SMART) trial who interrupted a fully suppressive NNRTI-regimen were evaluated. From 2003, SMART recommended interruption of an NNRTI by a staggered interruption, in which the NNRTI was stopped before the NRTIs, or by replacing the NNRTI with another drug before interruption. Simultaneous interruption of all antiretrovirals was discouraged. Resuppression rates 4-8 months after reinitiating NNRTI-therapy were assessed, as was the detection of drug-resistance mutations within 2 months of the treatment interruption in a subset (N = 141).

Results: Overall, 601/688 (87.4%) patients who restarted an NNRTI achieved viral resuppression. The adjusted odds ratio (95% confidence interval) for achieving resuppression was 1.94 (1.02-3.69) for patients with a staggered interruption and 3.64 (1.37-9.64) for those with a switched interruption compared with patients with a simultaneous interruption. At least one NNRTI-mutation was detected in the virus of 16.4% patients with simultaneous interruption, 12.5% patients with staggered interruption and 4.2% patients with switched interruption. Fewer patients with detectable mutations (i.e. 69.2%) achieved HIV-RNA of 400 copies/ml or less compared with those in whom no mutations were detected (i.e. 86.7%; P = 0.05).

Conclusion: In patients who interrupt a suppressive NNRTI-regimen, the choice of interruption strategy may influence resuppression rates when restarting a similar regimen. NNRTI drug-resistance mutations were observed in a relatively high proportion of patients. These data provide additional support for a staggered or switched interruption strategy for NNRTI drugs.

Trial registration: ClinicalTrials.gov NCT00027352.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • CD4 Lymphocyte Count
  • Clinical Protocols*
  • Drug Administration Schedule
  • Drug Resistance, Viral / genetics
  • Drug Resistance, Viral / immunology*
  • Female
  • HIV Infections / drug therapy*
  • HIV Infections / genetics
  • HIV Infections / immunology
  • HIV Reverse Transcriptase / genetics
  • HIV-1* / drug effects
  • HIV-1* / genetics
  • Humans
  • Male
  • Middle Aged
  • Practice Guidelines as Topic
  • Reverse Transcriptase Inhibitors / administration & dosage*
  • Reverse Transcriptase Inhibitors / immunology
  • Treatment Outcome
  • Viral Load

Substances

  • Reverse Transcriptase Inhibitors
  • HIV Reverse Transcriptase

Associated data

  • ClinicalTrials.gov/NCT00027352