Codeine and Tagamet?

[ironmics]

So I know the potentiation of codeine with tagamet has been discussed thoroughly before, but this one is different. After looking up some stuff about APAP last night I discovered that tagamet inhibits not just 3A4, but also 2E1. These are the two enzymes that produce the harmful effects of APAP. On wiki tagamet has unknown strength on 2E1 though. Does anyone know of any studies relating to 2E1, 3A4, and APAP. It seems that tagamet could lower the toxicity of APAP and make CWE's less necessary and potentiate it in one fell swoop. I'll try to find any info on it, but I just thought I'd throw out my observations.

http://www.sciencedirect.com/science...1d40e5fa15317e
I don't understand the last line, so I'm not sure if it does work.
http://www.springerlink.com/content/n126hk66832007v2/
This study backs up what I thought, but seems that timing of the cimetidine is very important.

[Paracelsus]

The last line basically says that cimetidine does not work (since "it is not able to reduce NAPQI formation").

Please use a descriptive thread title. This should be in the Pharmacology forum.

[Blacky]

Tagamet can increase effects of codeine? I thought the opposite, since codeine's action depends on its conversion to
morphine by CYP2D6.

Since tagamet will block this conversion you may not feel any effect it all.

Am I missing here something?

And according to what I understand, taking tagamet will amplify the effects of MDMA, since in this situation we don't want it to be metabolised, since MDMA is the active chemical. Therefore it could be possible to take tagamet and just a half tablet of MDMA to get the same effects of one MDMA tablet. Please pay attention, that's just theory which need to be confirmed by someone who taken Cimetidine prior to MDMA.