I have been on Tamsulosin for about a year now. I think this is the generic version of Flomax. 

I have not experienced any flu-like symptoms using it.  I will say.... it definitely helps with flow. When I need to go, I need to go.... don't wait around.  I do have to watch how much liquids I drink in the evening. Otherwise, there is a risk I may leak before I get out of bed in the morning.