Etravirine concentrations in CSF in HIV-infected patients

To determine etravirine concentrations in CSF in HIV-infected patients.

Twelve HIV-1 adult antiretroviral-experienced patients receiving an etravirine-containing regimen for at least 1 month were enrolled. Both CSF and blood samples were taken around 12 h after the last etravirine dose. Liquid chromatography-tandem mass spectrometry was used to determine etravirine concentrations, and HIV-1 viral load was determined by real-time PCR (limit of detection 40 copies/mL).

Twelve blood and 12 CSF samples were collected. The median CD4 count was 333 (84-765) cells/mm(3) and the median plasma HIV-1 viral load was <40 (range <40-1777) copies/mL. The median time on etravirine was 34 (range 4-140) weeks. The median etravirine concentration in plasma was 611.5 (range 148-991) ng/mL. The median CSF etravirine concentration was 7.24 (range 3.59-17.9) ng/mL; in all cases, values were above the IC(50) range (0.39-2.4 ng/mL). The median etravirine CSF:plasma ratio was 0.01 (range 0.005-0.03). The CSF viral load was >40 copies/mL in one patient and plasma viral load was still detectable after 4 weeks of therapy.

Etravirine achieves concentrations several times greater than the IC(50) range in CSF. All patients with undetectable plasma viral load were virologically suppressed in CSF while receiving an etravirine-containing regimen. Etravirine may help in controlling HIV-1 in CNS.