I just saw an commercial for Mercy, and I actually have to admit not only was it semi realistic, I actually laughed.
I can't find the youtube, but the scene is 2 nurses talking while Nurse A is administering morphine, and Nurse B is watching. The pt suddenly goes unresponsive, and Nurse B shakes him and asks how much morphine Nurse A gave. She replies "100mg". The Nurse B tells the Nurse A to bag him, runs, gets the narcan, slams it, and the pt sits up and pukes all over the Nurse A, who gave him the OD.
It all happened rather quick, and I'm not sure one preload of Narcan would help with that much Morphine, but they got the puking bit right at least.