Drugs making you a prima donna? (7)
I believe the answer is:
heroine
'prima donna?' is the definition.
(thesaurus)
I don't understand how the rest of the clue works.
(Other definitions for heroine that I've seen before include "The main good female character in a work of fiction" , "Emma, for example" , "Intrepid woman" , "Chief female character in a book" , "Woman of outstanding courage" .)