http://www.rxlist.com/decadron-side-effects-drug-center.htm : "Side effects of Decadron(dexamethasone) may include GI symptoms (nausea, vomiting), headache, acne or skin rash, increased hair growth, irregular menstrual periods, easy bruising, and anxiety, or depression......trouble sleeping, increased appetite, or weight gain"
I used to give a lot of Decadron ( one time IV injections) during anesthesia especially for ENT surgery like tonsils for kids. For one thing we felt it decreased airway swelling but the other is that it was just known as a major feel good and anti-nausea drug, at least for short term use.
But one time a bad respiratory thing was making it's way through the entire OR group, and I was offered a shot of the above drugs cousin Celestone(BETAmethasone rather than Dexa) as I was leaving in the afternoon. I had a 55 min drive home and then back again early the next morning. I started feeling better pretty soon. By bedtime, I was not sleepy. I got up wide awake at 3 AM in a panic, wondering what I was going to do about
work. If I didn't make it to work, an OR closed and 1/2 dozen folks would not get their surgery! But I was terrified I would become overwhelmed with fatigue mid day. By 0700 I was still wide awake, but not tired. I got to work and warned folks to keep an eye on me in case I became unsafe. But to my utter amazement I worked through the entire day feeling just fine, maybe with more energy than normal. I drove home, had supper and watched some TV, and maybe about
8 PM just totally crashed. I had completely skipped a nights rest- not even 10 mins of sleep- and showed no ill effects until a few hours before the next normal bedtime bedtime.
I'm don't know if decadron will have that kind of effect or not, but you might have to have some work for him to do!