Flomax side effects symptoms and conditions

I think i'm relatively young (29) however I was/am having problems emptying my bladder when urinating. Basically I finish and then a few minutes later some urine is still dribbling. My doctor gave me samples of flomax about a week ago. Recently i've been noticing my erections are awful and orgasm is weak. I checked this message board to see if anyone else was having the same problem. Not sure whether I should keep taking this or switch to uroxatral, another drug that i've taken in the past to stop the dribbling