I've never IV'ed coke, but I have snorted it a few times. I'm also prescribed an amphetamine, and I find Klonopin, a little bit of beer, and 10mg of Zyprexa (I also have a script for the Klonopin and Zyprexa for legitimate reasons) to be effective in getting to sleep. If you're looking to stay awake, but ease the comedown, I would recommend benzos, particularly Valium or Xanax. Also, eating fresh fruit (if possible) might help a bit, as would vitamins. In my coke experiences, high grade marijuana also seems to be effective.