copyright topical decreases effects of codeine by influencing hepatic enzyme CYP2D6 metabolism. Use Caution/Observe. Stops conversion of codeine to its Lively metabolite morphine. promethazine decreases effects of pitolisant by Other (see comment). Stay clear of or Use Alternate Drug. Remark: Pitolisant improves histamine ranges within the brain; as a result, https://wockusa.com/product/mdphp/