Phenergan is very commonly given along with injectable opioids (especially Demerol) as it will potentiate the opiates effect. When given alone, it will usually cause sleepiness. It is a wonderful nausea medication, but burns like hell when it is given IV or IM without diluting it with normal saline in the syringe. I never had one of my patients report euphoria, but a couple would tell me they felt kind of "floaty" and relaxed, but not euphoric. Hope this helps...