The overdose in 'Pulp Fiction' is a significant plot device. Mia Wallace's overdose on heroin is a moment that throws the story into a state of emergency. It shows the seedy and dangerous world that the characters inhabit. Vincent's panicked reaction and the attempts to revive her, like driving to Lance's place for help, highlight the risks associated with the drug - using lifestyle in their underworld. It's a moment that both shocks and drives the narrative forward.
In 'Pulp Fiction', the overdose mainly involves Mia Wallace. She accidentally overdoses on heroin. Vincent Vega was supposed to look after her while her husband was away, but things went wrong. Her overdose scene is a key moment of chaos and danger in the movie, which also sets off a series of events to save her life, like the adrenaline shot to the heart.
Well, in 'Pulp Fiction', the overdose situation with Mia is complex. You see, the whole atmosphere of the movie is this edgy, somewhat seedy underworld of drugs and crime. Mia was likely used to a certain lifestyle that involved drug use. But this time, she took too much heroin. It was a situation that could have been fatal. Vincent was responsible for her in a way, and his negligence, if you can call it that, led to this overdose. The way they handle it afterwards, with the crazy drive to get help and the rather unorthodox method of revival, really emphasizes the unpredictable and dangerous nature of the world these characters live in.