Hi Kelly,
Pyridostigmine and Prednisone are the usual first treatments for AChR Binding antibody MG. They can be viewed as stop-gap medications until you get on an immunosuppressant, like mycophenolate mofetil (Celcept) or azathioprine. The problem with immunosuppressants is they take a long time to work, typically many months. For me, pyridostigmine worked well enough to keep me moderately stable for the 10 months it took for azathioprine to kick in. I was lucky. If you are one of those for whom pyridostigmine doesn't work well enough or long enough, it's not unusual to get IVIG treatments or Vyvgart. to keep you going until the immunosuppressant works.
Prednisone is highly effective at bringing MG symptoms under control but has too many serious side effects to be used for very long. Your immunosuppressant should eventually replace all other medications except for stubborn cases and occasional flares.
Good question. Hope this helps.