How Can Osteoarthritis Be Treated?

I have osteoarthritis in almost every joint in my body and have noticed that almost every time on an antibiotic I feel so much better. My doctor says there shouldn t be a reason for that but I m telling you my joint pain is non existent when I m on a strong antibiotic. I was just in the hospital for a surgery and it happened again. I felt no joint pain while on the antibiotic drip and the first night I m home, my right shoulder was killing me. Can you shed any light on this?