Taking a Carbamazepine to conteract Fluoxetine (cyp inhibitor) So I can enjoy Codeine

[pally pete]

I've been on 20 mg of Fluoxetine (Prozac) for around 10 weeks. Last weekend I tried 300 mg of Codeine and felt next to nothing, even though my Opiate tolerance is low at the moment as I haven't used any Opiates since the start of April.

I'm guessing the cyp inhibition from the Fluoxetine is blocking the effects. I have plenty of Carbamazepine, which I hear is a strong cyp inducer. I've taken 200 mg of Carbamazepine around 50 minutes ago in the hope that it will be strong enough to counteract the Fluoxetine inhibition...?

I have 600 mg of Codeine ready to take, I'm just not sure how long I need to wait until the Carbamazepine gets into my system..? Usually an hour say?

Any thoughts or advice much welcome.

 

[keeping]

isn't 600mgs of codeine excessive? i think there's a ceiling to dosing codeine around 350mgs? i could be wrong tho, often am

 

[Pilll_head]

Yes, but you're inducing the wrong CYP. Carbamazepine induces CYP3A4 which make an inactive codeine metabolite. You want to induce CYP2D6 which converts codeine to morphine but you won't be able to get your hands on any meds that do that. Also you are probably right about the Prozac since it inhibits CYP2D6.

I think the max codeine dose is around 400 mg. Codeine is a weird drug because it also inhibits CYP2D6 which means it inhibits its own metabolism, which is why redosing codeine does not work (FYI hydro and oxy do not have this problem because they don't have to be metabolized at all to work)