Drug taker coming up with yours truly? Go on! (6)
I believe the answer is:
resume
'go on' is the definition.
(resuming is a kind of going on)
'drug taker coming up with yours truly?' is the wordplay.
'drug taker' becomes 'user' (I've seen this before).
'coming up' says the letters should be written in reverse.
'with' means one lot of letters go next to another.
'yours truly?' becomes 'me'.
'user' in reverse letter order is 'resu'.
'resu'+'me'='RESUME'
(Other definitions for resume that I've seen before include "Continue after a break" , "Start or take up again" , "Begin the summary again?" , "account, in brief" , "Take up where you left off" .)