Most of the cited medicines are still (or back) on the shelves in retail stores, mostly without prescription - at least in my area.
A note for the environmentally concerned, though: Reports from about the same era as the original warning above noted that casually discarded medicines can be toxic to the environment. The particular references were to discarded hormone and birth control medications, with the added note that many other common medicines may have "hormonal" effects on wildlife, especially aquatic ones. It makes the little fishies fail to reproduce normally, and has been blamed for a couple of instances of 5-legged frogs.
If you have medicines to get rid of, the recommendation is that you do NOT just dump them down the drain. Take them to your pharmacist, and request that he dispose of them properly.
And then he'll just dump them down the drain (just a guess).