It will be 2 years in March that I started Anastrozole. I did go through some side effects and at one point I was considering stopping, but the side effects were becoming tolerable. This past fall I started having terrible symptoms, I always felt angry, depressed, I was having heart palpitations, my hands looked and felt like they were crippling, I had burning sensation in my hands, feet, under arms, scalp, vaginal area, I had insomnia and blurry eyes. I could not figure out what was happening. I searched a lot online and there was a post from someone that said when the brand of their Anastrozole was changed, the side effects were unbearable. I looked back at my prescriptions and the pharmacy did switch brands in September and that was a 90-day supply. I had communicated to my oncologist the symptoms I was having and he told me stop the Anastrozole for 2 weeks. My hands felt 95% better after 3 days and the palpitations stopped. The other symptoms have subsided significantly. I am back on the brand that works for me and I am slowly feeling like myself. When I talked to the pharmacy about the symptoms I was having, I was told that they had another customer that had the exact same symptoms, from the same brand, that I was taking. So if any one notices a difference in how you feel after being on medication for a while, please check the brand.