Hi Beverly: I had taken beta-blockers on a consistent basis for a period of many months. During this time I would experience the "rebound" effect...it would help to slow things down at times, but other times I literally felt like my body was saying "no" to it and fighting it by sending me into hugh adrenaline rushes. After discontinuing a regular schedule of beta-blockers I began taking it "as needed". In other words, if I was having an adrenaline "attack", I would take it. Usually within 30-45 minutes it would slow things down. The only problem was that I would then slow down too much. I no longer take any beta-blockers. They just don't work for me. (By the way, I also tried Toprol. It did not help me....this was several years ago.) Another thing to consider is the amount of time the drug is in her system at a given moment. It depends on the beta blocker, but some stay in the system for a very short time. For example, inderal stays in the system for only a few hours. At that point it would still be likely to have adrenaline rush problems. Considering how sick your daughter seems, I wonder if you are getting the best care possible. The only reason I ask is because for years my docs in San Francisco told me I should go to Toledo to see Dr. Blair Grubb...I was too scared to hear what he would tell me. However, two years ago I moved to Ohio and felt I had no excuse but to see him...He has been an absolute godsend for me. He is not only brilliant and knowledgeable about all of this stuff, but he is also so tuned into every aspect of living with this type of illness. Next to my husband, he is my BIGGEST source of support and hope. Good luck! Kristen (violahen) before it beta-bloc