Can Using Femara Instead Of Exemestane Stop Fatigue, Vaginal Dryness And Joint Pains?

Hi, I have been on Exemestane for 3 months. I ve experienced hair loss, bone pain, joint pain, lethargy and extreme vaginal dryness- even with primarin cream. Today my doctor told me to stop taking it for 3 weeks and then begin Femara. I ve read the side effects are the same as Exemestane. Why would switching a drug with the same mechanism of action provide any benefit? Thanks for your response.