If you had asked in the translation section (English missing), we might have suggested a translation like 'coked up (to the gills)
Here unfortunately there's no field for it, or for sources, but nevertheless here are some related words that might help, including a few that LEO doesn't seem to have.
coke - der (auch: das) Koks (Kokain)
nose candy (Amer.) - der (auch: das) Koks
to sniff snow - koksen Dictionary: koks*
to get high (on sth.) - sich (mit etw.) zudröhnenDictionary: zudröhnen
zukiffen - (vr) (sl) to get spaced out (sl);
zugekifft - spaced out (sl)
zusaufen - (vr) (sl: = sich betrinken) to get pissed (Brit inf) /or/ plastered (inf)
zuschütten - ... (vr) (mit Alkohol) to have a skinful (Brit inf), to be two sheets to the wind (US); (mit Drogen) to get completely drugged up (inf)
I don't know whether Duden has a definition for this sense of 'zu-' as a prefix.
To me it looks loosely analogous to verbs that imply filling up in a negative way, likezubauen
See what the native speakers say.
(*f5* Sorry, too slow.)