Penetration of efavirenz into the male genital tract: drug concentrations and antiviral activity in semen and blood of HIV-1-infected men

Efavirenz is a potent non-nucleoside reverse transcriptase inhibitor, licen sed for the treatment of HIV-1. Data on sanctuary site penetration are limi ted. Therefore, we measured efavirenz concentrations in the blood and semen of 19 HIV-1-positive men and found concentrations in seminal plasma averag ed 10% of those in blood plasma. Furthermore, seminal plasma viral loads we re suppressed by 24 weeks of therapy in all patients. These data suggest th at efavirenz-containing regimens have antiviral activity within the male ge nital tract.