Dwayne these are a few I could come up with also some come from the EMS Field guide.
Heroin = "H", Horse, China white
Methadone = Redneck Heroin
Cocaine = coke, snow, flake, Bolivian Marching Powder, nose candy
Crack Cocaine = crack, rock
Methamphetamine = meth, crank, speed, beans
GHB = "G", easy lay, liquid X, Blue nitro
LSD = acid, purple microdot, sid
marajuana = pot, weed, grass, smoke, mary jane
oxycodone = oxy,"oc"
PCP = angel dust, peace pill, horse tranqulizer, dust
good luck.