Anticholinergic/sedative combos decreases levels of promethazine by inhibition of GI absorption. Applies only to oral kind of both equally agents. Use Caution/Keep track of. Opioids are sought by drug abusers and folks with addiction disorders and they are subject to legal diversion. Consider these hazards when prescribing or dispensing TYLENOL® https://wockusa.com/product-category/research-chemicals/