Atypical pharmacokinetics of atazanavir in an HIV-1-infected patient.

An HIV-infected patient with very low atazanavir (ATV) plasma trough concentrations despite clinical signs of poor drug tolerability was described. By therapeutic drug monitoring (TDM), the authors found that the patient had an atypical ATV pharmacokinetics characterized by rapid drug absorption followed by very fast drug clearance probably attributable to his genetic background. This case underlines the importance of traditional and pharmacogenetic-based TDM for the individualization of ATV therapy in HIV-1 patients.