I believe that Rush was referring to drugs in the sense of non-prescription drugs like cocaine or heroine. Could you provide a reference where he was talking about pain killers?
This would open up the obvious come-back of "one cannot so casually segregate drugs. An illegal drug is an illegal drug." The funny thing is that so many people on this forum say this about narcotics (heroine, etc.) and steroids.
Even more amusing is that steroids are take for recreational purposes, whereas pain killers are taken for just that, the relief of pain.
As for myself, I have zero tolerance for pot, cocaine, heroine, etc. users; But I do have tolerance for people hooked on pain killers. Perhaps you and Cowpimp have never needed to rely on pain killers for a long period of time, but believe me, it makes life almost unbearable. People often kill themselves rather than experience the pain.
I'm not actively condoning Rush, but, like it so often happens, not everyone here is looking at the big picture. Myopia is seldom a good thing.