Where do all the dead pills go?

We seem to be accumulating lots of bottles full of medication that
Shawn is no longer taking. Today we added topamax to that collection,
although it will take 3 weeks for him to wean himself off it.

I'm not quite sure what to do with all these. At the moment they are
all dumped into a big baggie which is starting to get full. It did
come in handy though when trying to list all the medicine he's taken
for the last 6 months.