Daily codeine affecting oxycodone BA?

[Starshowers]

Okay so I am under the impression that codeine and oxycodone are metabolized with the same group of liver enzymes.

Lately I've been using high doses of codeine daily (sometimes with diphen, but not always)...

I use oxycodone every once in awhile (like once a month).

Lately oxycodone has lost its magic (even though I'm keeping up with tolerance.) By this I mean I still feel the oxycodone effect and nod a little bit but I no longer have the extreme social euphoria/stimulant properties that I've always had previously with oxycodone (and I've used it 100+ times with this same effect). Note that I always and only have dosed orally.

Could this be because of the extreme CYP2D6 inhibition that I have from daily codeine use? Or are the enzyme levels restored within 24 hours?

I just want to know if the magic is gone from tolerance or from temporary CYP2D6 inhibition.

As I've said, I've used oxycodone for years (mostly occasionally, a couple small binges but NO addiction/wthdrawal EVER). All of those experiences were beautiful, but my last one was not. my tolerance is around 80-120mg. I did 100mg last time and it sucked so bad I was even slightly depressed. I think because I was expecting the super social euphoric stimulant effect though... not the true opiate nod).

Thanks and sorry if this is super-elementary.

 

[Captain.Heroin]

So what dose of oxycodone are you taking? Is it an extended release or instant release preparation?

 

[Starshowers]

So what dose of oxycodone are you taking? Is it an extended release or instant release preparation?

Well I take between 80-120mg OxyContin (whatever I can afford) and I crush them into fine powder then I stir in like 50mL of water, then drink it. I am confident that I get rid of nearly all of the time-release characteristics doing this. I've done Oxy IR and Percocets as well many times, but these days just the Contins.

 

[Starshowers]

All I need to know really is how long CYP2D6 inhibition lasts from codeine, and if this enzyme is even a major part of oxycodone metabolism. I know it has a part, I just don't know how significant.

 

[Trevor99]

I am curious about this too. I was on Codeine for a few months before switching to Oxy just 2 weeks back. I was doing about 120mg to 180mg of Codeine per day but never any Oxy, I got some Oxycontin 40mg tabs and took half for my first dose which was good I felt it, I am about 2 days in I took a whole 40mg and chewed it and damn that was the best high I have had in a long time, but since that one this week I have taken 40mg the rest of the week with no so much feeling, I thought it might have to do with my taking it after supper and it not getting into my system with a full stomach. I even took 60mg one of the days and it was not so much. I know in a 1 week my tolerance did not jump from 0- over 60mg now, it must be something else.

Just today I took 3 Tylenol 4's and did not really get that much of a good buzz but that too was after eating, so I am curious to your question about the liver enzyme as I take both of those drugs and as to the oral strength of these taken after food.