Green’s Dictionary of Slang

(US drugs) a cocaine addict.

1936		D. Maurer ‘Argot of the Und. Narcotic Addict’ Pt 1 in AS XI:2 119/2: charlie coke. A cocaine addict.
1949		Monteleone Criminal Sl. (rev. edn).
1953		Anslinger & Tompkins Traffic In Narcotics 306: Charlie Coke. A cocaine addict.
1960, 1975		Wentworth & Flexner DAS.