If you get pulled over and they do a drug screening & your prescription drugs show up you may be facing a misdemeanor, there are no levels to this law as there is to alcohol consumption. It doesn't seem to matter how long you've been on a particular prescription. If you read the labels on your prescription or over the counter medication almost all drug companies are putting on the label may cause drowsiness, do not drive until you see how this medication affects you.
Why is this important?
I've been personally effected by this law & don't want to see others going through what I am