I've recently started getting severe panic attacks. My doctor prescribed me .5 mg Xanax (1-2 every 6 hours as needed). Taking 1 did not help, and neither did 2. So I called him and he told me to try taking 3 at a time, and then 4 only if that didn't help. So after another episode I tried taking 4 and it did somewhat help... but my question is this. Taking 4 of the .5 mg would equal 2 mg total. I've taken an actual 2mg bar in the past and that helped tremendously, nothing compared to taking 4 of these 0.5's. Why would the 2mg bar work so much better then 4 of these 0.5s if technically they are both 2mg? Is it maybe due to it being made my a different manufacturer? The ones I have now are by Actavis, and the bars were Sandoz. My dr told to me call him to let him know how taking the 4 worked, and I want to be able to just get written an actual 2mg Rx rather then having to take 4 of what I currently have. I wish I could just be upfront and tell him the 2mg helped me way more then these but its not a possibility unfortunately to tell him that.