Promethazine
"I take this medication for nausea caused by endometriosis pain.  I apparently had also taken it on and off for most of my life, since doctors used to prescribe it to me when I could not stop throwing up.  I only realized recently that the pill that worked so well to stop my vomiting and the one I had just been prescribed were one and the same.  Previously I had been on Zofran, but it only stopped me from throwing up; the nausea persisted.  This medication stops the nausea and gives me an appetite.  My one complaint is that it causes terrible drowsiness for me.  I can be fully rested, but then if I take one pill, I am a walking zombie. So I try to use it sparingly.  Of course, sometimes the drowsiness is worth it."