Impact of body weight on virological and immunological responses to efavirenz-containing regimens in HIV-infected, treatment-naive adults

AIDS. 2015 Jan 14;29(2):193-200. doi: 10.1097/QAD.0000000000000530.

Abstract

Objective: The prevalence of overweight and obesity is increasing among HIV-infected patients. Whether standard antiretroviral drug dosage is adequate in heavy individuals remains unresolved. We assessed the virological and immunological responses to initial efavirenz (EFV)-containing regimens in heavy compared to normal-weight HIV-infected patients.

Design: Observational European cohort collaboration study.

Methods: Eligible patients were antiretroviral-naïve with documented weight prior to EFV start and follow-up viral loads after treatment initiation. Cox regression analyses evaluated the association between weight and time to first undetectable viral load (<50 copies/ml) after treatment initiation, and time to viral load rebound (two consecutive viral load >50 copies/ml) after initial suppression over 5 years of follow-up. Recovery of CD4 cell count was evaluated 6 and 12 months after EFV initiation. Analyses were stratified by weight (kg) group (I - <55; II - >55, <80 (reference); III - >80, <85; IV - >85, <90; V - >90, <95; VI - >95).

Results: The study included 19,968 patients, of whom 9.1, 68.3, 9.1, 5.8, 3.5, and 4.3% were in weight groups I-VI, respectively. Overall, 81.1% patients attained virological suppression, of whom 34.1% subsequently experienced viral load rebound. After multiple adjustments, no statistical difference was observed in time to undetectable viral load and virological rebound for heavier individuals compared to their normal-weight counterparts. Although heaviest individuals had significantly higher CD4 cell count at baseline, CD4 cell recovery at 6 and 12 months after EFV initiation was comparable to normal-weight individuals.

Conclusion: Virological and immunological responses to initial EFV-containing regimens were not impaired in heavy individuals, suggesting that the standard 600 mg EFV dosage is appropriate across a wide weight range.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antiretroviral Therapy, Highly Active
  • Benzoxazines / administration & dosage*
  • Benzoxazines / therapeutic use*
  • Body Weight*
  • CD4 Lymphocyte Count
  • Cohort Studies
  • Female
  • HIV Infections / drug therapy*
  • Humans
  • Male
  • Middle Aged
  • Obesity
  • Regression Analysis
  • Reverse Transcriptase Inhibitors / therapeutic use*
  • Treatment Outcome
  • Viral Load

Substances

  • Benzoxazines
  • Reverse Transcriptase Inhibitors
  • efavirenz