View Full Version : Anyone IV/IM Nucynta tapentadol?
04-04-2011, 02:50 PM
Anyone IV/IM Nucynta tapentadol?
I'm just curious because I was thinking since its oral bioavailability is listed at about 32% and its allegedly water soluable, then I am curious if the method described in the oxy forum would work for this pill (ie. "Sticky: A (safer) simple IV oxy prep guide" ...wiping the coating off, crushing and soaking in 130ml of cold water, filtering twice in shot glasses, etc.)
a friend actually suggested it and offered to ginea pig, but I told SWIM not until I consulted with "the board"
04-04-2011, 03:19 PM
Tapentadol comes in the form of it's hydrochloride addition salt, freely soluble in water at physiological pH. Apparently the low bioavailability (32% fasting condition, 32% fed conditions) is due to extensive first-pass metabolism by the liver.
MOR - 0.2-0-23 μM
Norepinephrine - 0.6-0.62 μM
It also apparently binds to the β1-adrenergic, 5-HT2a, 5-HT transport, σ2 & the PCP-site of the glutamate receptor. It's MoR : Other-opioid receptor selectivity is about 10. This is a bit of a mix, not very nice at all, I suspect. More worrying is the different effaciacy depending on ROA. In mouse studies the MED50 are 21mg/kg oral but 1mg/kg IV. In rats it was 68.1 oral, 0.464 IV. This is a MASSIVE difference.
I think I'm correct in thinking tapentadol will be a LOT stronger IV; possibly an order of magnitude or more. Certainly I have one reference of adverse effects from the drug starting with 10mg. Certainly it's Ki at the MOR receptor is a lot lower than morphine.
You may have stumbled on a very inexpensive rescue medication for broke & desperate junkies... in the end there is only one way to find out for sure. Slow titration from 1mg would be my advice; we need a report, after all ;-)
04-04-2011, 03:25 PM
yeah the idea and goal was that it would be stronger and the obvious fear, given that it snorts like the worst thing you ever snorted, would bring into question would someone want to risk trying this to get a triple effect.
hmm. thanks boro.
if we decide to test at some point, I'm only going to allow him to test on the 50mg rather than the 100. I'll post a full report if we do test.
04-04-2011, 03:40 PM
... Certainly I have one reference of adverse effects from the drug starting with 10mg. ...
is this implying that if we were to test IV, try to put 10mg or less in the water? that might be a bitch to measure considering the smallest pill is 50mg... hmm this worries me.
04-04-2011, 03:42 PM
I suggest you start lower than 50mg; it may equipotent 1g swallowed! It's not just a MOR agonist so you cannot rely on tolerance working in your favour. DOR & sigma agonism can cause respiratory depression (and seizures, possibly made worse by norepinephrine activity), KOR can cause hallucinations and dysphoria.
This stuff just hasn't got enough research into IV administration to know the risks & overdose will certainly be harder to deal with than any amount of heroin (for example).
IF it proves to be a good hit, however, I've already got a pretty good idea how a much stronger (and totally legal) analogue can be made. In fact, I suspect the only reason that this analogue wasn't used in the original was patent infringement.
04-04-2011, 03:49 PM
well, then, given your advice, I will not proceed with any such experiments until I can get my hands on a milligram scale and weigh these bastards. thanks again!
04-04-2011, 04:03 PM
someone here has, cant remember who though. Maybe one eye? idr
04-04-2011, 04:11 PM
dissolve in 50ml of water. 1ml = 1mg. Just go for the highest concentration you can while maintaining the ability to measure +/- 5%. 1mg would seem an appropriate place to begin. Titrate upwards 50% each time (so 1mg, 1.5mg, 2.25mg, 3.375mg and so on). If you want to read how it was done for the original buprenorphine test, I posted it earlier.
04-04-2011, 05:06 PM
that makes sense. duh, im an idiot, i dont need a microgram scale. lol. boro, you rock. Next time I see SWIM, I'm gonna have him try this and tell me the results. gotcha on the the titration.
04-04-2011, 05:31 PM
This stuff reaches peak plasma concentration between 1 & 1.5 hours which is a slower than some opioids (a lot slower than some) so 10 minutes between shots, even if it appears that nothing more is happening. It's a very 'dirty' drug from a pharmacological standpoint (binds appreciably to many receptors) and the body is, after all, one big self-feedback mechanism. I really would not care to predict all of the physiological changes it will induce.
FYI replacing the phenolic -OH with a carboxamido -CONH2 will undoubtedly lead to a material far, far more orally active and undoubtedly with a longer duration of action.
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