In the UK, terrible puns are de rigeur, but the answer has to be a recognisable standalone word or phrase. So 'poisoned pen' could be an answer, and the clue could conceivably contain a pasta-based pun on that, but 'poisoned penne' could not.
Additionally, I would say that that, because the answer isn't a coherent standalone word/phrase, that particular clue/answer combo would only be found in a puzzle as part of a hidden theme shared by a number of 'special clues' throughout the crossword, with some kind of rule uniting the answers (add 'ne' to the end of a common phrase, for example).
And more complicated variants, like anagrams, mashing words together, etc.