Not sure if I have posted this info re letrozole before, but I had aching joints, including wrists, fingers, elbows, knees, ankles, on Letrozole (fbm brand). I changed to Anastrozole (fbm) which the onc said would not make symptoms worse, but might improve them. That was in April, and my symptoms have definitely improved. At the same time I also lost about 10 kilos through diet change and swapped from fish oil to glucosamine, and cut down a lot on sugar where I could. I don't really find it is better or worse with or without exercise.
So not really sure which of these changes resulted in the improvement, or whether it was a combination of all of them. The onc seemed to think it was the weight loss, but I don't see how that would improve areas like fingerrs wrists and elbows.
I didn't have any problems adjusting to the new med, and I haven't noticed any new side effects. And it is slightly cheaper (about $23 compared to about 33 from memory at Chem warehouse.
The way I see it, if you are really miserable on Letrozole, why not try anastrozole. You have nothing to lose, and they both do the same job.
I hope your aches improve, whatever your decision. It's not fun being old when youre not!