Here's what rhymes with diphenhydramine.

Consider these alternatives

phenylephrine / line promethazine / seen carbamazepine / oxcarbazepine hydroxyzine / seen ibuprofen / chosen paracetamol / regional tyramine / nine azathioprine / line amitriptyline / skyline salicylate / late chlorhexidine / seen hydrocortisone / shown lorazepam / can oxazepam / can papaverine / seen tretinoin / join clonazepam / can hydrochloride / chloride citalopram / can phenacetin / meeting theophylline / seen buspirone / alone quinidine / seen atropine / line spironolactone / backbone