I Have Been Prescribed And Taking Tamsulosin Because Of Inability

I have been prescribed and taking tamsulosin because of inability to urinate at night. After couple of months of tamsulosin I do urinate to some extent even at night. some side effects I noticed are 1. mild ache of the kidneys, especially when twisting or turning the body. 2. At times short alert from need to urinate to inception of uncontrollable stream. Are these normal? Should I ask for alternative medication? The Tamsulosin did decrease my PSA from 16 to 10. Thank you.