I too had this reaction from prednisone. I thought my ex husband was trying to kill me. Every time a tail light reflected on my glass front door of where I used to live I thought my ex was aiming one of those guns with a red beam on them at me. My heart also beat really fast, so I told my doctor and he took me off the pred. My mind was somehow translating real things the wrong way. The other day I had a cortisone shot in my heel for a heel spur, and I even warned the doctor about this, but he said it shouldn't affect me too bad. Thankfully the only reaction that was negative was my foot was in more pain and stiff for a couple of days. I wonder if there is much difference between taking the prednisone in pill form and getting an injection of cortisone. This is a very real reaction that some people get from prednisone. It's called "Steroid Psychosis" and the symptoms should stay away once off the Prednisone.