Alot of coke songs about that time, Jackson Browne's Lawyers in Love for example.
I am thinking that Eric Clapton was doing the nasty with Geo Harrison's wife about the time "Cocaine" came out which leads me (pretty tricky) to My Guitar Gently Weeps but not Georges version .... its a "group" thang, but check out the solo part yawl will NEVER believe the artist and talent!!
http://www.youtube.com/watch?v=ifp_SVrlurY