Propranolol as a prophylactic treatment

After not having migraines for close to 10 years, my migraines have returned with a vengeance. I was prescribed propranolol ER as a prophylactic treatment. I also have familial tremor so I am pretty much killing two birds with one stone. However, I have been having very intense dreams and I was told that it should go away with time. So, my fellow unlucky souls, I come to you to ask how long it took for the dreams to disappear. Thank you!