In the case of A-N Med i 245, the edition suggests that the word is used as an adjective (‘medicated with opium’) and therefore adds an accent. As the trifera magna electuary is believed to have been an opiate in itself (not listed in the DMLBS sub trypheros 3517b), it is more plausible to read the word as a substantive, placed in apposition: ‘trifera magna, [the] opiate’.