Prednisone does cause wakefulness and anxiety -- the anxiety, at least for me, subsided quite a bit after the first few days.
I've always had insomnia and when the prednisone made it even worse the rheumy prescribed Trazodone - really nice to sleep the whole night! Others have found relief from something as simple as OTC melatonin, or some variety of sleep aid.
(I know some use Benadryl for sleep -- it makes me wired for 2-3 days so haven't tried it for decades!)
Lynnwood, Lupus & Sjogren's Moderator, Dx: 2002DIAGNOSING LUPUS & LUPUS RESOURCES
"Life is far too important to be taken seriously." - Oscar Wilde