Diclegis. What's your experience?

Ok... i am taking this... just one at night. It seems to work pretty well for nausea but by 5pm I am useless tired. I know im supposed to take 2 at night but one makes it hard to fall asleep so for now I am sticking with one. Has anyone else only taken half the recommended amount? Has it done the same thing to you? What have been your experiences?