Contributing Factors for Poor HIV Treatment Response in Children With TB/HIV Coinfection

Efavirenz (EFV)-based antiretroviral therapy (ART) remains the preferred regimen in human immunodeficiency virus (HIV)-infected children aged 3 years or older on rifampin-containing antituberculosis (anti-TB) therapy. This is because drug interactions between first-line anti-TB therapy with protease inhibitors (PIs) are more severe to adjust for, and interactions with integrase strand transfer inhibitors (INSTIs) are not well studied in that age group. Although, current weight-based EFV dosing recommendation is not optimal in some children, pharmacokinetic-treatment response (PK-PD) data to guide optimal dosing of EFV during concurrent rifampin-containing therapy in children is very limited. The study team propose that EFV concentrations outside the optimal therapeutic range in children will be associated with virologic failure due to lack of efficacy because of low concentrations or increased central nervous system (CNS) toxicities from high concentrations leading to poor medication adherence. The study will determine virological suppression rates in HIV-infected children with and without TB coinfection treated with standard efavirenz-based therapy and examine the factors contributing to poor virologic response.