What are the side effects of prednisone 5mg 6 day pack?

Very few. Short courses of Prednisone or Medrol (methylprednisolone) are commonly used for a a variety of conditions like acute gout, poison oak, and allergic reactions. Since the treatment is less than a week, there are few potential problems. Some patients have a little insomnia or anxiety with the higher doses given in the first few days of the pack.