My Dr Prescribed Methylprednisone Because I Have A Ringing In

my dr prescribed methylprednisone because i have a ringing in my left ear and negative pressure on my right ear. Whenever I am on prednisone I have to stop taking the because i break out in hives all over my arms legs ears. I tried benadryl and it didnt stop the itch nor the hives. I have to start on a new pack tomorrow. i want to know whats the best dose to start with incase i have to stop abruptly due to the hives? I was given 4mg dospak 21's. and i have to take 6 on the first day, 5, 4, 3, 2, 1. can i also take B12. Its the B12 drops that one puts underneath the tongue.