I am the 7%

[MrPorter]

Just tried codeine for the first time (after allergy test) and very little response. I took ~150mg and all I got was some tinnitus and an ever so slightly limp hand, which is the one I normally sleep on top of.

Basically, my questions are...
1. Am I the 7% that can't use codeine due to lack of CYP2D6 enzyme?
1b. If so, does this effect other drugs?
2. What happens to the codeine otherwise? Just gets changed into other useless stuff by enzymes I do have I presume...
3. Would I still be able to overdose (obviously not going to try, just interested)

I'm not taking any medications, and I had just finished recrystallising 1200mg of the stuff before dosing

 

[nAON]

Just eat a higher dose and see what happens. Too early and not enough information to make any real conclusions.

 

[Swimmingdancer]

Do you have any tolerance to opioids or have you used any other opioids before?

 

[MrPorter]

^none at all at the moment
What dose would you recommend next then, 200mg?

 

[Swimmingdancer]

But have you used opioids at all before?

If you didn't feel anything whatsoever (other than unwanted side effects) from 150mg, then I would assume codeine doesn't work for you. You didn't notice anything like pain relief, calmness/relaxation/decreased anxiety, drowsiness, feeling warm, comfortable, pleasant etc? Personally I would just not bother with it. But you could also try taking less, like 60mg, as some people strangely report getting better effects from lower doses.

Does your codeine have anything else in it, like APAP? If so, that is something you really don't want to be taking too much of.

You can try a higher dose if you like but I wouldn't advise going above 300mg. People have died from as little as 450mg. I would probably try a lower dose before a higher dose personally.

Also one thing about codeine allergies and sensitivities is that they don't normally show up until you've used it a few times.

As to your question about overdosing, not getting high off it doesn't necessarily mean you can't overdose or have bad side effects, so still be careful.

 

[Snowy]

Basically, my questions are...
1. Am I the 7% that can't use codeine due to lack of CYP2D6 enzyme?
1b. If so, does this effect other drugs?
2. What happens to the codeine otherwise? Just gets changed into other useless stuff by enzymes I do have I presume...
3. Would I still be able to overdose (obviously not going to try, just interested)

1. Possible, but you can't say for sure if you tested this gene for it's exact subtype.
A good method to be quite sure is to test the metabolism of 2D6-substrates like DXM.
Another method to make an educated guess is to try venlafaxine and see if you get pronounced side effects with correlate highly with 2D6-deficiency.
If you are interested i can get you the ref..
1b. Yes, other 2D6 substates: Amphetamines, DXM and a few other.
2. Morphine is not the only active metabolite. Codeine-6-glucuronide is one and not a minor one.
3. Yes, see 2..

BTW: I am very likely not a slow 2D6 metaboliser and have a similar problem with codeine.
Opioides have a rather high variability in their effect on individuals, thus there a widely differing preferences...

 

[nsauce]

lol you got a limp hand?
(sorry, couldnt resist)

 

[effie]

1. I doubt it - codeine's effects are not just due to morphine but also codeine-6-glucuronide which is metabolised by a different pathway..

1b. Yes loads of drugs are metabolised by CYP-2D6 like snowy said.. There's a lot of info if you google it of there's chart *here*. Drugs are often metabolised by multipe pathways though and people don't always tend to have a clinical difference in the doses they need.

2. Codeine is also metabolised to codeine-6-gluronide as I said, and inactive metabolites too via different pathways. It's also renally excreted (by the kidneys).

3. Opioid overdose causes respiratory depression and death.. be careful!