HI SUE,
Well i also got rsd after a hip replacement. mine was about 11 years ago. i also got nerve palsy from the surgery.
i have not used topamax, but have been on neurontin for many years. i too held out and tried to use pain meds but none worked. the neurontin has helped more than anything and i would not go off it.
don't be afraid to try a new medication, just monitor yourself carefully for any changes and let your doctor know right away if anything feels wrong. actually a med like topamax or neurontin is more apt to help with nerve pain that narcotics. good luck and let me know how you make out.
joan