I've had steroid IV once, myself. My first bout of Optic Neuritis. Still took, 10-12 weeks for my vision to go back to normal.

Not certain about for pain, I have had steroids orally, and by a shot, during times of sinus infections, I know that the steroids can help other medicines become more effective, so I recall.

I didn't really enjoy my iv experience. I was 25, alone, and had to squeeze it into my work schedule.