I took Xtandi for 26 months. Sorry your father is experiencing insomnia. I never had it. I had fatigue and some swelling in my legs. It’s a wonderful drug and if you look at the data from Prosper trial you will feel confident your father is on the right treatment. I owe to Xtandi that I have been in remission for 4 years now. Wish the best to your dad and your family.