Promethazine is metabolized from the liver to a range of inactive metabolites like sulfoxides of promethazine, N-demethylpromethazine and various glucuronides.The concomitant use of Promethazine HCl and Codeine Phosphate Oral Solution with all cytochrome P450 3A4 inducers or discontinuation of the cytochrome P450 3A4 inhibitor may result in lower c