I am so confident that you will never get into any trouble with the mentioned meds that I will promise to pay any and all legal bills if you do.
As mentioned, there is a possibility of getting a seizure letter from some over zealous customs worker, but I would be quite surprised if that occurs. Prednisone is a catabolic steroid. The feds are concerned with anabolic steroids. These are different entities entirely. No worries.