I have a low tolerance for meds, but Ativan takes 2 milligrams before if works for me. When my doctor used to prescribe .5 milligrams, I had to take 4 in order for it to help my anxiety. Now they prescribe 1 milligram pills and I need 2 for it to be effective. I tell them this, and they still prescribe 1 milligram doses which I find odd. I don't take them daily, I go several days between because I'm worried about memory loss and dependency. If I take them at night, I wake up with serious med hang over though. Antihistamines can cause me to get hyper, or feel very sluggish and worsening my depression. I always thought my unpredictable responses to meds (one time it does nothing, the next I'm raging out of control because of the same med and dose) was a bipolar thing but I haven't noticed too many people here discuss an unpredictable response to meds. Like someone said, they are downers so it makes sense they can effect you as such. I'm sorry you have this reaction and I hope you find something to work for you. I currently just avoid all things anxiety causing right now. I spend most of my time locked away in my house. That is not a treatment plan I would recommend to anyone, though it does work somewhat. It's really not a sustainable way to live.