The Efavirenz (EFV) Central Nervous System Exposure Sub-study of Encore1
Status:
Completed
Trial end date:
2013-02-01
Target enrollment:
Participant gender:
Summary
Persistent HIV infection in the central nervous system (CNS) compartment may put subjects at
risk of developing HIV-related brain disease. Important factors associated with the
development of HIV-related brain disease include therapeutic concentrations of antiretroviral
drugs in the CNS. Conflicting evidence regarding the CNS exposure of the antiretroviral drug
used for the encore1 study, efavirenz (EFV) have been described in related studies. There
were recent study of two small series assessment of EFV exposure in the cerebral spinal fluid
(CSF); one group reported small detectable EFV concentrations, while another observed
undetectable EFV exposure in the CSF. Also, in a larger reported series comprising of 80
subjects on EFV-containing antiretroviral therapy, a CSF to plasma concentration suggested
that there is limited movement of EFV out of the CSF. In HIV-1 infected subjects at steady
state, EFV plasma level parameters are dose proportional following 200mg, 400mg, and 600mg
daily doses. The CNS exposure of EFV at different daily dosing has not been described.