, ritonavir) or discontinuation of a cytochrome P450 3A4 inducer for example rifampin, carbamazepine, and phenytoin, may cause an increase in codeine plasma concentrations with subsequently better metabolism by cytochrome P450 2D6, resulting in greater morphine levels, which could improve or prolong adverse reactions and could induce potentially lethal respiratory https://trentonpsqol.ltfblog.com/31341022/the-greatest-guide-to-akorn-promethazine-codeine