• N&PD Moderators: Skorpio | thegreenhand

Duration of N-phenylethyl morphinan opioids


Mar 31, 2022
I'm wondering if the N-phenylethyl homologue of morphine (x8 morphine in potency) has the same duration as morphine. After all, in MOST classes, when you swap from N-methyl to N-phenylethyl, the duration goes down. This is entirely dependent on if an appropriate enzyme will 'fit' with the biosteric bulk of the class.

For fentanyl CYP3A4 removes the N-phenylethyl.

Not many other classes have has specific metabolism of the N-phenylethyl homologues examined. I presume that is why BDPC has such a long duration. Their is no N-phenylethyl.
No - I said I didn't have any data on the morphinan class - that was the reason for the question.

I don't think any enzyme data will be extant, but I'm hoping their is a paper in which potency and duration of something like N-phneylethyl normorphine (for example) is compared to morphine..

It just a 'many eyes' question. If you ever read it, you would, I presume, recall if duration fell hugely.
if you add a phenethyl instead of the usual methyl on the N of dihydroethorphine, where would you end up? something 20000x morphine?
btw, i even find hydromorphone a bit to tightly binding to the mu receptor, plain morphine is way nicer. its like with amt and 5meo-amt but with these i liked 5meo-amt even a bit more than amt. buprenorphine is something else, really hard opioid but without the tachyphylaxis building up a nice high.