Change in Sleep Architecture and Neuropsychological Performance Following Switch From Atripla to Stribild.

Atripla (efavirenz/emtricitabine/tenofovir disoproxil fumarate) and Stribild (elvitegravir/emtricitabine/tenofovir disoproxil fumarate/cobicistat) are 2 FDA-approved 'one pill once a day' combination antiretroviral medications given for the treatment of HIV. Both have a common nucleoside reverse transcriptase inhibitor (NRTI) backbone of tenofovir (TDF) and emtricitabine (FTC), but differ in the 3rd medication contained in the pill. Atripla contains a non-nucleoside reverse transcriptase (NNRTI) drug efavirenz (EFV) while Stribild (elvitegravir/emtricitabine/tenofovir disoproxil fumarate/cobicistat) contains an integrase inhibitor elvitegravir with the drug cobicistat inactive against HIV but designed to simply boost the level of elvitegravir.

Both drugs are reasonable well tolerated. However, efavirenz is known to cause 'mental' side-effects. It is known that the initial use of EFV is associated with central nervous system (CNS) toxicity. The symptoms of such toxicity include daytime sleepiness, or alternatively inability to sleep, as well as vivid dreams including nightmares. The majority of such symptoms are believed to resolve within weeks; however there is controversy as to whether residual problems persist on a long term basis. Furthermore there are now reports of long time cognitive dysfunction associated with the use of efavirenz. Whether this is related to sleep disturbance is not clear. Studies to assess this impact have primarily involved assessment of sleep and cognitive function in antiretroviral (ART)-naïve subjects as they are initiated on first time ART that includes EFV. Such studies however are confounded by a 'return to health' phenomena as HIV per se is known to cause sleep and cognitive deficits . There is controversy regarding whether use of efavirenz leads to long term disturbances in sleep and cognition. HIV per se causes sleep and cognitive deficits6 and studies which have tried to assess problems in antiretroviral-naïve subject's pre- and post- initiation of efavirenz-based regimens may be confounded by a 'return to health' phenomena.

This proposal aims to assess whether a switch from efavirenz/emtricitabine/tenofovir disoproxil fumarate to elvitegravir/emtricitabine/tenofovir disoproxil fumarate/cobicistat will be associated with reversal of sleep and cognitive disturbances. Demonstrating changes upon withdrawal of drug and substitution of a drug regimen not known to have an impact on sleep or cognition may represent the best option to determine whether use of EFV is associated with effects on sleep and cognition beyond the immediate period following initiation of drug.