Hey I saw your post and thought I would chime in. I'm having a hard time finding accurate comparisons between this and other more-common Opioids. I'm sure they're out there if you're willing to dig into some medical literature.
It is compared to Mepiridine (Demerol) frequently from what I've read. Its indication for moderate-severe pain would kind of support this notion.
Do you have it in front of you or is this just curiosity? Either way we would start with the allergy test and some small oral doses afterward till we know what's up. Let us know and we will do our best!