It is possible to develop adverse reactions to any prescription drug, Jenna. It would be very hard for one of us to tell you “Yes, it is” or “No, it isn’t” the drug, however. Joint pain is a listed adverse effect of the antithyroid drugs. Whether the side effect would appear as long as a year after starting the drug, I don’t know. This is definitely a question you should discuss thoroughly with your doctor.
Bobbi