Promethazine Hydrochloride And Codeine Phosphate + Phenytoin Interaction
Majorinteraction on record
Description
CYP3A4 inducer reduces codeine levels and morphine formation, decreasing efficacy or causing withdrawal syndrome. Avoid use; if necessary, monitor for reduced efficacy.
Mechanism
Induction of CYP3A4 decreases codeine metabolism by CYP2D6, lowering morphine levels
Source: NLP:promethazine hydrochloride and codeine phosphate