I (and my wife, each) was on Toprol XL, a beta blocker type of blood medication, for 2-3 years. I have been prone to anxiety/panic attacks for most of my adult life, but I was getting anxiety that was worse than before. I finally had a panic attack that my prescribed benzo wouldn't touch, in a dose that was 1 & 1/2 times that I was supposed to take in a single day. By chance I checked a website called askapatient.com which has patient ratings & reviews of drugs. I discovered that 1 in 3 patients who had taken Toprol XL for the long term (2-3 years) had complained of anxiety. I called my Dr that day & got off it, and my wife got off it too, as she had gotten edgier. Felt much better in several days.