I'm amazed that there appears to be no slang term even mentioned for a simple (and in my circles anyway), very commonly used combo: CRYSTAL METH and BENZOS. I admit I may have missed it going through the above posts but to propose a new term. I searched online for ages and could not find ANYTHING even from a list of 2,500 drug combos!
You sort of need a verb and a noun, so:
Anything METH related that might fit well could be: SPEED/SPEEDING, CRYSTAL, ICED/ICE, CRANK/CRANKING, GLASS, TWEAK/TWEAKING, WHIZZ/WHIZZING
Anything BENZO (trying to keep general) might include: BAR/BARRED/BARRING, BENDING (from Kitty-Bending), HELPERS, STOPPERS/STOP/STOPPING, BLANKING/BLANKS/BLANKED, PLANKING, JELLY/JELLIES
So combining, perhaps:
ICE-BENDING
CRYSTAL-BENDING
SPEED-BENDING
WHIZZ-BARRING
GLASS-PLANKING
SPEED-PLANKING
BAR-SPEEDING
JELLY-TWEAKING
or in a different format you could have:
ICED-JELLIES
CRANK-HELPERS
GLASS-JELLIES
ICE-BARS
GLASS-BARS
CRYSTAL-BARS
WHIZZ-BENDERS
CRYSTAL-BENDERS
Dunno, Think I like: SPEED-BENDING or WHIZZ-BENDERS