Cigarette smoking decreases amounts of promethazine by growing metabolism. Use Caution/Keep track of. Conversation predominantly witnessed w/chlorpromazine & thioridazine, but may perhaps manifest w/other phenothiazines. promethazine decreases effects of pitolisant by Other (see remark). Steer clear of or Use Alternate Drug. Comment: Pitolisant will increase histamine levels within th... https://wockusa.com/product/pai-promethazine-vc-with-codeine-oral-solution/