noun
habitué, devotee, fan, enthusiast, fanatic, adherent, practitioner, drug abuser, user, substance abuser, alcoholic, chain smoker, junkie*, fiend*, nut*, freak*, regular*, -aholic (used in combination), druggie*, pill popper*, hophead*, customer*, head*, dope fiend*, drug fiend*,
cokey*, mainliner*, crackhead*, snowbird*, tripper*, acidhead*, pothead*, speed freak*.
