Guide drug addict around hospital (5)
I believe the answer is:
usher
'guide' is the definition.
(ushering is a kind of guiding)
'drug addict around hospital' is the wordplay.
'drug addict' becomes 'user' (I've seen this before).
'around' means one lot of letters goes inside another.
'hospital' becomes 'h'.
'user' enclosing 'h' is 'USHER'.
(Other definitions for usher that I've seen before include "One who shows people to seats" , "Theatre/cinema worker" , "Doorkeeper; shower to seat" , "Cinema or wedding attendant" , "R and B star" .)