I went to college in the 1970's, and at the time Quaaludes were a very popular recreational drug, especially with the girls. They relax you and give you a slight high... the gals loved them.
You would have to take several to get knocked out... taken one or two at a time was like having a good drink... a little buzz, relaxation, etc.
My girlfriend's roommate always had a stash of Quaalude's, Valiums and stuff like that. I tried them a couple of times, and frankly they did absolutely nothing for me... even with several beers on top of them.
Cosby's statements are absolutely in line with what the party scene was like back then, and in no way "proves" anything other than he was hip with the times.
Cosby is not a perfect man, or maybe even a good man. He did stand up to the Left, however, and demand better behavior from the Black community, which put him on the Left’s sh!# list.