50 mg of Prednisone once a day for 3 days??

At the very least heartburn. It will irritate your stomach. Nausea could be a problem. Here is what the manufacturer has to say about side effects. https://www.drugs.com/sfx/prednisone-side-effects.html

It caused me to have a very short temper, angry and impatient. But this is a common side effect for women who are prescribed steroids.

You took your first dose. How did it go? Flushing, sweating, shaking, heart pounding are some of the side effects. Sleepless, very hungry or very not hungry. You can get through it. Been on it on high dose for years. Be sure to take half in the morning and half at night with food. A meal not a glass of milk. Your stomach may be affected otherwise. Omeprazole may be something to try. Hope the prednisone helps. Write again if you have questions, Karen

Jitters, impatience, buzzing in ears, angry... This is how I get with the 40mg a day x3 then tapering off, hate it! But I hope it helps you, side effect will go away in a couple of days. This was my experience several times.