Well, the first thing you need to do is change your doctor. There was a time when it was believed that rheumatoid arthritis was due to an infection.
Many doctors used to prescribe tetracyclines for rheumatoid arthritis. This was based on pure speculation and today we know different. There is not one piece of evidence linking rheumatoid arthritis to any bacterial or viral organism. However, some old fashioned doctors continue this antibiotic therapy, more out of ignorance rather than anything else.
There is no proof that rheumatoid arthritis is due to an infection and no one has ever been cured of his or her disease with an antibiotic. Today, there are far better and more effective therapies for rheumatoid arthritis than tetracyclines. So get yourself a new doctor or search online for a reputable rheumatologist.