Detailed Description:

Individuals will be recruited who are currently users of cannabis and alcohol to participate in this study. They will undergo a physical exam at screening. There will be six study visits where the subject will arrive at the Clinical Research Unit(University of Iowa Hospitals & Clinics) the night before dosing. At each visit subjects will be receive one of the following six dosing regimens: placebo alcohol with placebo cannabis; placebo alcohol with low-dose cannabis, placebo alcohol with higher-dose of cannabis, low dose alcohol with placebo cannabis; low dose alcohol with low dose cannabis, low dose alcohol with higher-dose of cannabis. After dosing, participants will have provide saliva samples and blood drawn periodically to check cannabis levels and will complete a driving simulation. After completing the drive, additional saliva samples and blood draws will occur and participants will be monitored until it is safe to transport home.