Opioids Pethidine (Demerol)

[Feretile]

I have read quite a few posts by people praising what is quite a moderate opioid. I am interested to understand why it should be so euphoric, at least in those will little or no opiate tolerance. I'm also interested to hear from anyone who has had the chance to try both pethidine (Demerol) and tilidine (Valaron/Valtran). I suspect it is because both agents are also dopamine reuptake inhibitors, but I have tried pethidine (an ampoule - but I drank it) and even on top of a LOT of methadone (266mg), I did get a small, stimulating butt. Nothing amazing.

It could also be because it has some NMDA affinity in which case, so does tilidine so I would expect them to be subjectively similar.

Many thanks.

 

[negrogesic]

I have taken a good amount of pethidine (or what we call meperidine here). Around 12-13 years ago there was an Asian-Canadian vendor that was selling meperidine powder in bulk. I bought 20 grams of it, but had a large opioid tolerance then and when i tried it, it felt very weak.

It sat in a drawer for maybe 6 years, at which point i found myself in withdrawal from a much smaller level poppy pod habit. Needless to say I went through those 20 grams quickly (I believe mostly orally since I had stop IV drug use at that point).

It was ok, a very quirky feeling opioid with clear stimulant effects. Best way I can characterize it is like a short and fast acting methadone feeling, combined with a bit of methylphenidate. Dirty feeling though. Actually the closest feeling opioid to meperidine in my experience was high dose loperamide, which feels very meperidine-like (just longer acting and less stimulating). I would say 200mg* of loperamide feels like maybe 150mg of meperidine in terms of central effects (but more in terms of peripheral effects). Of course high dose loperamide doesn't feel exactly like meperidine but it is the closest. Also i suppose not surprising given the structure, O-desmethyltramadol is also a little reminiscent of meperidine, perhaps more so if you throw in some methylphenidate into the equation. That said the opioid qualities of meperidine feel closer to loperamide than to O-desmethyltramadol. Meperidine feels less MOR selective than O-desmethyltramadol (ie, it feels like a more robust full bodied opioid with some KOR and DOR activity too). Do you happen to the know affinity ratios for meperidine (ie, MOR:KOR:DOR ratio)?

I'm sure the meperidine would have been better if I had injected it. I still somewhat regret not injecting it given that it is pretty rare these days (and the parenteral route is where it's known to shine anyhow). Better that i didn't i suppose, to do so would break a self-imposed rule I gave myself around a decade ago: no IV drugs for me unless it is 1) formulated for injection (ie, vial or ampule), 2) not expired, and 3) not veterinary grade. Essentially this rule pretty much assures that I inject nothing

* no one should take this much loperamide in any circumstance

 

[izo]

They made some ring substituted (mostly halogens) derivatives which turned out to be quite strong dari‘s on top of it’s mu agonism properties, suspect them to quite icky substances.