Promethazine

Promethazine...anyone know much about it?! This is what I took last pregnancy (3 years ago) and what I was prescribed this time for the horrible nausea/vomitting. I took my first last night and it definitely helped (it wasn't totally gone or anything but much better), but it made me soooo tired/drowsy. No way I could have functioned during the day after taking one! Anyone else experience this? Remedies? I really want to be able to take something to make life bearable