Nevada medical marijuana users are concerned as the state’s dispensaries open for business in 2014 that they could easily violate Nevada’s DUI standard; driving with more than 2 ng of marijuana per milliliter in your blood, or 5 ng of marijuana metabolite. Cannabis has a stricter standard than cocaine or heroin (50 ng), methamphetamine (100 ng) or LSD (10 ng), and there is no exception for medical marijuana patients.