Atazanavir systemic exposure (ATV exposure)

Atazanavir systemic exposure refers to the concentration-time profile of the protease inhibitor atazanavir within the systemic circulation (FDA, 2023). It is a critical pharmacokinetic parameter rather than a biological target, used to guide dosing and ensure therapeutic efficacy in the treatment of HIV-1 infection (PubChem, 2024). The exposure is typically measured by the Area Under the Curve (AUC) and trough plasma concentrations (Cmin), which must be maintained above the inhibitory concentration for the virus to prevent treatment failure and the development of resistance (StatPearls, 2023). Atazanavir's absorption is pH-dependent, requiring an acidic environment, and its clearance is primarily mediated by the CYP3A4 enzyme (PubMed, 2020). Consequently, systemic exposure is often managed through pharmacological "boosting" with ritonavir or cobicistat and is sensitive to interactions with acid-reducing agents (NIH, 2023). While necessary for viral suppression, high systemic exposure is frequently associated with benign indirect hyperbilirubinemia due to the drug's inhibitory effect on the UGT1A1 enzyme (PubMed, 2021). Monitoring these levels is a standard part of clinical pharmacology to optimize patient outcomes in antiretroviral therapy (FDA, 2023).

Other names

Atazanavir pharmacokineticsAtazanavir AUCAtazanavir plasma concentrationAtazanavir Cmin

Atazanavir systemic exposure is a pharmacokinetic measure and does not have a biological mechanism of action. The drug atazanavir itself acts by inhibiting the HIV-1 protease enzyme, which prevents the cleavage of viral Gag-Pol polyproteins into functional subunits, thereby halting the production of infectious HIV-1 particles (PubChem CID 148192; FDA Label, 2023).