Doctor upset with German article on painkiller (7)
I believe the answer is:
codeine
'on painkiller' is the definition.
(I know that inception subproperty of point in time)
'doctor upset with german article' is the wordplay.
'doctor' becomes 'doc' (synonyms).
'upset' says the letters should be written in reverse.
'with' is a charade indicator (letters next to each other).
'german article' becomes 'eine' (indefinite article in German).
'doc' written backwards gives 'cod'.
'cod'+'eine'='CODEINE'
(Other definitions for codeine that I've seen before include "Pain-relieving derivative of opium" , "Common painkiller" , "Derivative of opium used as an analgesic" , "Analgesic drug" , "Niece, do take this drug" .)