2 questions about Codeine

[d3Xo-fan]

Hi,

I have two questions about Codeine:

1) I can get by with 50-75 mg Codeine a day. I switched to Codeine sometime last week; before that I was on methadone. My question is this: do you think there will be any w/d's if I cold turkey now, and if yes, how bad do you think they'll be?

2) I know Codeine is a prodrug since approx. 10% is converted into morphine. Now let's say morphine has an oral bio-availability of exactly 20%. Does this mean it's 20% of the 10% that reaches the brain? For instance if I took 100mg Codeine by mouth, would that yield 10mg Morphine or 2mg Morphine (20% of the 10% that is converted)? In other words, is morphine's B/A relevant when you don't take Morphine directly, but rather have your liver create it for you? Or is it only Codeine's B/A that is relevant?


- DF

 

[effie]

Hi there,

1. That is not a high dose of codeine - did you have any withdrawals switching from methadone to that? I would imagine that any discomfort would be minimal at that dose, but I would still try to taper if possible as you have been on opioids for longer than just the time you have been taking codeine..

2. Codeine's metabolism is a little more complicated than first thought. A lot of it's opioid action is now thought to come from a different metabolite, codeine-6-glucuronide, so you get more than just 10% of the morphone dose. The percentage is based on the amount of drug reaching the liver - anything absorbed from the gut heads to the liver before the brain, so 10% of the codeine you absorb will be converted into morphine. I am not sure what percentage is coverted to codeine-6-glucoronide...

Morphine's bioavailability is irrelevent as that relates to how much morphine is absorbed into your bloodstream, not what happens to the morphine after it is absorbed.

 

[d3Xo-fan]

Hi Effie,

I did experience some discomfort some 48 hours after switching to Codeine... I suppose the delay is due to methadone's long half life. I experienced the usual feeling of electricity inside my arms/legs. I am pretty much sure all the methadone has been eliminated, and I haven't experienced w/d's since, but I will continue tapering like you suggested.

And thank you for your answer to my second question, it was exactly that sort of information I was looking for

 

[bullet_and_the_gun]

Like effie said that's not a lot of codeine. I think methadone takes about 10 days to leave your body completely. From my experience, once you are somewhere between 30-60mg of codeine a day, you can go down to zero pretty easily. Physically it doesn't make a big difference at all, and when I did that I only felt very mild withdrawal symptoms. However, tapering may make it easier, especially psychologically.

 

[d3Xo-fan]

I've experienced the same thing. I managed to get clean a few months back by tapering down to 25mg codeine per day, and when I jumped to 0mg I felt no noticeable w/d's. So basically I'm just trying to repeat the success. The reason why I fear w/d's is that last time I was on Codeine I was on it for weeks, perhaps more than a month. But this time I've only been on Codeine for perhaps a week tops. And last time I was on a small dose of Codeine I tried to skip a dose and got pretty unpleasant w/d's, but that was because I had only been on Codeine a few days (just as I have this time around so far), but after having been on Codeine for a much longer period I was able to completely stop taking it and not feeling withdrawals.

Perhaps I should ask: how long do you gather it would take for the receptors to get used to the weak agonist Codeine is? In other words, how long would you stay on a low dose of Codeine before completely stopping?