Detection of low-frequency K103N mutants after unstructured discontinuation of efavirenz in the presence of the CYP2B6 516 TT polymorphism.

Objectives: To measure antiretroviral drug plasma levels in newly diagnosed HIV-1 seropositive persons who presented with an undetectable plasma HIV-1 RNA load but gave no history of antiretroviral drug exposure and to determine the impact of interrupting undisclosed or unknown antiretroviral therapy on the emergence of drug resistance.

Patients And Methods: Five newly diagnosed, reportedly drug-naive HIV-1 seropositive persons were included in the study. Drug resistance was determined by population and clonal sequencing of reverse transcriptase and protease.