If a drug gets metabolized faster or more efficiently, its effects are diminished. A lot people have a polymorphism, meaning genetically, they either cant metabolize a drug well, or they do it too well. This could be the case.with you. Dph is a cyp450 inhibitor, which will help you feel the codeines effects.
As far as diclazepam, I dont have too much background on it, so idk which enzymes metabolize it. But dph could inhibit its metabolization, but there's no need to take that large of a dose.
Dxm is otc, so no pharmacist needed. You could go to a self check out aisle even.
- Hopeless 7nos