Is It Safe To Use Exemestane For Severe Ankle And Foot Pain?

I have had terrible ankle and foot pain after 2 and one half years on arimidex. The doc switched me to exemestane and had no problems until 2 days ago extreme feet pain and having trouble walking again and I love to walk. I have only been on exemestane for 2 months and thought Thank Gosd my ankle pain went away but now I have feet pain...unreal. Which anti estrogen tablet has the least side effects of joint pain???????????????