Shannon, when you say "unreasonably frequent urination," how unreasonable do you mean? Multiple times per hour? And how many mgs of pred are you currently taking?
I pee frequently too - I go about once every hour - and I'm currently not on any meds. I think I just have a small bladder, plus I drink tons of water, tea, gatorade, etc as I tend to get dehydrated very easily so I drink as much as I can to try to avoid another round of dehydration. How much do you drink and do you drink things like coffee, caffeine, alcohol, etc? Those things can cause you to have to urinate more frequently too.