Obviously there is truth to the allegations, but...

In the book American Desperado, Jon Roberts mentions the widespread use of quaaludes at parties. The quaaludes were simply dumped into large bowls of punch...and the girls would chug it down. Those drugs were referred to as "leg openers" at the time. They served to turn on a woman's sexual nature, not incapacitate them.

Then take a look at Benadryl, mentioned above. Three one half pills of Benadryl will make you drowsy, but not drowsy enough that you are no longer responsible for your actions or incognizant. A full dose of benadryl is two whole pills, not three halves. People take benadryl everyday...and they can function. You can't rape them. They are not under hypnosis, nor are they magically obedient.

All of that said, I think if any of these women knowingly put a pill in their mouth, taken from Cosby's hand, I wouldn't call that particular instance rape. To me it would have been more incriminating for Bill if he was getting the women drunk from alcohol instead. Alcohol is altogether different.