Objectives: The pharmacokinetics of antiretroviral drugs may differ in elderly people living with HIV (PLWH) because of age-related physiological changes. We aimed to assess the pharmacokinetics of several antiretroviral drugs in aging PLWH enrolled in the Swiss HIV Cohort (SHCS).
Design: Full pharmacokinetic profiling nested in a multicenter, observational, prospective cohort study. Additional collection of single point pharmacokinetic data during SHCS follow-up visits (unselected PLWH).
Methods: PLWH were eligible for the full pharmacokinetics investigation if they were over the age of 55 years, on a stable boosted darunavir-containing or dolutegravir-containing regimen. Single point measurements were prospectively collected during SHCS follow-up visits to compare antiretroviral drug exposure in aging (≥65 years) and younger (<65 years) PLWH.
Results: Nineteen PLWH with a median age of 64 years participated in the full pharmacokinetic investigations. Single point pharmacokinetic data were collected for 804 PLWH with a median age of 52 years. Boosted darunavir clearance was 40% lower in aging (≥65 years) compared with younger (<65 years) PLWH, consistent with other drugs predominantly metabolized by CYP3A. Dolutegravir exposure was similar between age groups whereas lamivudine exposure increased by 11% in aging PLWH. Median boosted darunavir, dolutegravir and lamivudine t1/2 were 148%, 45% and 32% higher in aging compared with younger PLWH.
Conclusion: Advanced age did not affect boosted darunavir exposure to a clinically significant extent despite the observed high variability in exposure. Age minimally affected dolutegravir and lamivudine exposure. Thus, dose adjustment based on age is a priori not warranted.