I know from experience, and from the stories of other drug addicts and from what I've been told by various bupe and methadone doctors I've had over the years....The affinity of bupe and fentanyl is pretty damn close...Fentanyl is what many ER doctors would choose to use in an emergency for someone in need of pain relief that was dependent on buprenorphine.
Also, it's not like one opioid/opiate has a higher affinity and that's it, period....You can cut through the blockade of a high affinity opioid with one that has a "weaker" affinity with a high enough dose....
For example: If you do enough heroin on top of 12 mgs of buprenorphine, it will eventually break through the bupe blockade. It's not safe and predictable, but it's possible..
I personally know of someone who was on Suboxone, who was severely injured and on a maintenance dose of bupe at the time.... The ER doctor just used IV morphine to cut through the bupe. It did eventually work, it just took a massive amount of morphine! Which kind of makes sense, if you think about it....
As someone pointed out earlier, fentanyl and bupe both have such a high affinity for "whatever" receptors, that if you attempt to break through the bupe blockade with fentanyl and something goes wrong and respiratory depression occurs, naloxone may not work to bring the person back....If you use morphine, however obscene an amount it may take to break through the bupe blockade, you know the effects of the morphine can be completely reversed with naloxone...
Just a layman's opinion
