I am a dialysis patient & do not produce urine. I have a very large prostate. I recently underwent surgery to remove blood clots from my bladder. I have been on Finasteisde for 6 weeks and experience countless spasms that are painful sending shocks throughout my body; like when you have to "Pee' and nothing comes out. This goes on all day and night. Is this a normal reaction, and how long will this go on?