The energy that coke gives you isn't really useful for enhancing academic performance. The high is short lived, the hangover is rough, and the "energy" mostly consists of the user thinking that every random though that pops into his head is so interesting and insightful that it needs to be communicated to all present at 2X normal human speaking speed.
While I've never been into study drugs, Adderall is a better bet for improving performance. Coke is just going to make you talk really fast for a half-hour, then you'll crash and you won't get much done tomorrow morning.
If you're doing coke in med school, it's really just a way to blow off steam; not a way to gain any kind of useful energy.