Sara Anne,
Thank you so much for your help. I know I should ask the doctor/nurse, but I just feel like I'm being annoying when I ask too many questions. I don't know why he would prescribe this. He's an older doctor, around 68, but I don't know who are the bulk of his patients. I've been going to him for 15 years for kidney stones, and he seems rather conservative, but I really like him.
Thanks again.