It made my joints hurt so bad and the hot flashes (which will go with all of the estrogen blockers) that I finally changed to letrozole.  The hot flashes are horrible, but taking 800 mg of magnesium has helped.  I do have what they call trigger finger with the letrozole which is a normal side effect.  The meds seem to make your body feel like a flu system at times.  I'd go off of it if I weren't so afraid of getting the cancer back.