For example, have you ever wondered why some prescriptions require ID at pickup? Surprisingly enough, it is NOT because the pharmacy staff wanted to see your crazy driver's license photo and we are NOT on a secret mission to find all the people with expired IDs (there are more than you would think). ID requirements for dispensing are determined by the category of drug prescribed. So what are those categories? I thought you would never ask.
I like to start with the simple stuff: non-controlleds. These are the blood pressure and cholesterol medications no one wants to take anyway. Hence, the government does not need to "control" how they are handed out. (That might be a slight exaggeration seeing as how the government LOVES to control things.)
This is where we start getting into the "potentially addictive" medications. Some people like to take these more than they should and so the powers that be require various levels of tracking to try to keep people from hurting themselves. CV is fairly weak stuff (like codeine cough syrup) while CIV and CIII become progressively more dangerous (think Lortab and Xanax). Drugs are assigned to these levels by state legislatures so, in theory, it can vary from state to state but in actuality it doesn't very much. You will probably never notice. Anything CV or higher will require an ID before you get to take it home.
This is the stinky stuff. These prescriptions have a lot of restrictions on them and are the most "potentially addictive" substances available at the pharmacy. Which makes sense since most of them are amphetamines used to treat hyperactivity disorders and I think we all know how easy it is to quit methamphetamine. (It isn't, FYI.) Drugs are assigned to this category on the federal level.
And, with that, we have covered all the medications your run-of-the-mill pharmacy dispenses. (I tricked you by saying it was amazingly intricate, so sorry.) Now, my bright crayons out there are saying--"what kind of categorization system goes from 2 to 5?" Ah ha! You caught me! There is one more category, CONTROLLED SUBSTANCE LEVEL 1, and this is where all the really bad boys hang out. This category is the federal government's way of designating something as illegal to possess or distribute and it includes marijuana, cocaine, methamphetamine, PCP, etc. (Those are actually all the illegal drugs I could think of. I live such a crazy life.)
There go my bright crayons again! Yes, marijuana is illegal on the federal level which is why you cannot transport it out of any of the states that have now legalized its use (this is a tricky legal thing and I will not try to explain it to you and make a fool of myself). Also, for those who are curious, cocaine is actually used in a few specialized medical procedures but in teeny, tiny amounts with obsessive levels of control over it. Can you imagine the paperwork involved in that?
One final note: for someone working in a profession where the job description is basically "knows about drugs" I know very little about illegal medications and I would guess most other pharmacists are the same. For some reason I was always satisfied with, "just say no." However, there are people out there with legitimate concerns and questions about illegal drugs and researching those substances is very difficult (and not really Google material). If you are one of those people, I highly recommend Erowid.org.