In some cases Prednisone will make MG symptoms worse before they get better, but from what my neurologist told me is that by starting low and going slow it is less likely to get worse.

From my experience (I currently take 60 mg daily) it got worse a few times before getting better. I ramped up at 10 mg / week.

I've experienced improvements each time I ramped up within 2-4 weeks after the dosing change.

Check out the myasthenia.org website under living with MG to find more info on Prednisone that will help answer your questions.