Impact of obesity on antiretroviral pharmacokinetics and immuno-virological response in HIV-infected patients: a case-control study.

BACKGROUND

Obesity has high prevalence among HIV-infected patients. Increased adipose tissue mass affects the pharmacokinetics of numerous drugs, but few data are available for antiretroviral drugs.

OBJECTIVES

In this study we aimed to explore the pharmacokinetics of antiretroviral drugs and the immuno-virological response in obese patients with HIV infection.

PATIENTS AND METHODS

We examined data from 2009 to 2012 in our hospital's database for HIV-1-infected patients who received an antiretroviral drug (abacavir, emtricitabine, lamivudine, tenofovir, efavirenz, etravirine, nevirapine, atazanavir/ritonavir, darunavir/ritonavir, lopinavir/ritonavir or raltegravir). Obese patients were defined as those with BMI ≥30 kg/m 2 and normal-weight patients as those with BMI 19-25 kg/m 2 . Plasma concentrations ( C 12/24 ) were compared for each antiretroviral drug using a Mann-Whitney test. Suboptimal dosing and virological outcome were assessed by logistic regression, adjusting on covariates.

RESULTS

We enrolled 291 obese and 196 normal-weight patients. Among the 12 analysed antiretroviral drugs, tenofovir, efavirenz and lopinavir C 12 values were significantly lower in obese than normal-weight patients: 66 versus 86 ng/mL, 1498 versus 2034 ng/mL and 4595 versus 6420 ng/mL, respectively ( P  <   0.001). Antiretroviral drug C 12/24 values were more frequently below efficacy thresholds for obese than for normal-weight patients after adjustment for other covariates ( P  <   0.001). Although obese patients showed a higher CD4 count than normal-weight patients (510 versus 444 cells/mm 3 , P  <   0.001), the groups did not differ in virological failure rate.

CONCLUSIONS

This study highlights the impact of obesity on antiretroviral drug plasma exposure, but identifies no consequence of this suboptimal exposure on the immuno-virological control in this population.