Does this mean it will stay in my system longer? On and off I've used adderall xr over the years. Just yesterday and today I've taken about 120mgs over the last 2 days. I'm not doing any more, I'm done. but i start cna classes the beginning of January, they are 3 weeks long and I'm pretty positive they give the drug test after you pass the classes. I'm deathly afraid I'm going to fail because of how much I've abused this drug over the years. Should i be worried?? and if they do give it at the beginning of the classes, what are my chances of passing?