Strange O-desmethyltramadol withdrawal

[clubcard]

I appreciate your scientific rigour, serotonin2A. If I'm wrong, I'm wrong - but then I learn something new - thank you.

 

[PINKoPANaTHER]

I think the confusion here, is, clubcard is right that delta agonism seems to have an observable affect on a molecules potency, but that does not mean that it affects withdrawal syndromes. I would assume that a combined mu/delta agonist may have a distinct withdrawal, but i have never heard of w/d not responding to the fentanyls which as stated above are strictly mu agonists.

There are strange things with the opioid receptors though, for example U-4770 is a strong kappa agonist but has been reported to be very euphoric and pleasant (if only for a short time, like the fentanyl analogs).