When I had my wisdom teeth pulled they gave me Vicodin as a pain killer and it made me wired for a couple of hours. I talked non stop and cleaned the house non stop. Afterwards I would get very sleepy. It's a very dangerous drug and very addictive too. A friend of mine ended up in rehab for it. It nearly destroyed her liver and it ruined her marriage.

Scales are more for Pot and cocaine, not OTC or Rx meds. Pills can be counted and sold, the other stuff can't.

Edited to add that the only reason I can think that one would even have a drug scale is to sell them, not use them.