Say you use heroin or have used it in the past. Now you have to go in for some kind of surgery. Guess what? The opiate pain meds won't work for you! I've seen it first hand. It's awful. Hospitals are only allowed to give so much and if you're a user or were a user, the amount they give you won't touch your pain.
Guy who used heroin shattered his hand in a fall off a roof. Had pins put in. When he came around after surgery they had to call the police he was so out of control because his pain couldn't be managed.
Opioid tolerance will absolutely decline if you stop using. it's actually a significant cause of death. People will quit (or go without due to jail, etc) and then relapse with the same dose they has used before and have a fatal overdose.
Morbid but curious question: when tolerance declines, does a de-rated dose (say, 100% of the body's safe mechanical limit) produce the same mental effect as the previous, now way higher dose would? IOW, does the tolerance affect the mental response as well?
(NB. Have integrated the understanding that pushing The Button™ is a generally bad idea. The above is purely intellectual curiosity.)
Guy who used heroin shattered his hand in a fall off a roof. Had pins put in. When he came around after surgery they had to call the police he was so out of control because his pain couldn't be managed.