I have been taking letrozole 2.5 MG for 2 years. Lately, I have been experiencing joint and muscle pain in my lets and feet. I get so sore it is hard to walk. I am 66 years old, but very active. I work in the lunch room at a local high school and am on my feet for 5 hours a day....lots of lifting is part of the job, and lately the pain is almost unbearable. I also walk daily, 30 to 40 minutes every evening and that is getting harder to do as well. Can I just be starting side effects from the letrozole after 2 years, and if so, is there something that can be done?