... Anxiety,irratibility, trouble concentrating, agitation. Could these possibly be side of effects of the higher dose of this medication? I was on 150 for about 6 yrs. And the doctor and I felt that it wasn't working as well as it had been so he increased it by 75mg. In Aug. I felt fairly well for and was doing well, until the last 3 or 4 weeks. I can't sit still, I'm snapping at others, I feel twitchy all the time, I've started have problems with night sweats, and bad dreams.