Mr Blonde
Bluelighter
dnaenterprises1@ya said:Mr Blonde, can you tell us a bit about timing with CYP2D6 inducers like Promethazine?? How long before dosing do you take them? What happens if you take them after the codeine? Is Promethazine and Doxyalime and diphenhydramine all about the same?
Certainly.

As belarki pointed out, they are not CYP2D6 inducers. Promethazine is in fact a CYP2D6 inhibitor, doxylamine has no effects as far as I can tell and diphenhydramine also inhibits CYP2D6.
However, as far as I can tell with promethazine it's effects on CYP2D6 aren't really noticeable and it goes great with codeine. Diphenhydramine I didn't really enjoy with codeine, just made me drowsier but not in a good way, and doxylamine is OK (just been using around 50mg with codeine recently) but not as good as promethazine, which I find gives a really nice sedation.
The best way I found to dose was to take the promethazine around ten-15 minutes before taking the codeine so that they were coming on at similar times (codeine comes on very quick for me). This way as well, CYP2D6 interaction should be minimal.
I have taken promethazine after I've already taken the codeine, and found there was not much difference aside from the effect that there wasn't really the feeling you get as it comes on with the codeine at the same time. You may want to experiment a little to find your sweet dosing spot though, as I generally tend to feel drugs quicker then other people.
However, as long as you are feeling the sedative, anti-histamine and anti-emetic effects of the anti-histamine at the same time as the codeine, you are set. :D