Hi Finding - The cortef was prescribed by an endocrinologist. When I needed it most, it was impossible for me to go without. Yes, I would black out upon standing, but that could also happen without me moving at all. I was extremely fateagued, dizzy and lightheaded, too. The cortef alleviated my symptoms and gave me energy I hadn't had for years. One of the things my doctor suggested to help with both my low blood pressure and the irregular heartbeat was that I get back to exercising. At that time the Lyme symptoms weren't so bad and, though I was afraid, after a complete cardiology workup (where they also recommended more exercise) I started going to the gym regularly and slowly my bp got at least high enough that I did not need the cortef on a daily basis. I had to go very slowly since exercise is physically stressful, and I didn't want to cause a bigger problem. When I started, I was still on cortef, but was eventually able to wean off of it. I still have low bp, but now I control it by adding enough salt to my diet and making sure that I stay hydrated. Very important, though - I waited until my doctor suggested I try cutting down on the cortef dosage. At every juncture I was under medical supervision. I did not do this on my own. Also, to this day, I cannot undergo a physically stressful procedure, not even dental surgery (found out the hard way when we all agreed I could try it without a megadose of steroids and I spent the whole time fighting to maintain consciousness) without steroids. If you have adrenal fateague, cortef (or other steroid therapy) replaces the deficient cortisol your body would naturally produce. We need that to maintain bp and other functions during stressful physical occasions.
I don't know what florinef is - is that a steroid? Chances are that the dose you are taking is not high enough to seriously impact your immune system. If it is helping with your symptoms, then I think it is a good thing until your body is well enough to take over. The book I mentioned in a different thread is called Adrenal Fateague by James Wilson and Jonathan Wright. My LLMD recommended it to me. I ordered my copy from Amazon, used, and it was very inexpensive. I liked it because there were many dietary and holistic suggestions.
My LLMD told me Lyme can take down the adrenal glands and he thinks this is what happened to me. It is encouraging to see that my endocrinology tests indicate my function is a little better now than it once was. To me this means the Lyme treatments and the dietary and holistic things I am doing are working. Good luck with this; I hope my response was of some help, and if you have any more questions, please ask.
I have Lyme; it doesn't have me.