Tamsulosin side effects?

Tamsulosin helps you pee faster by relaxing the smooth muscle of the prostate and internal urinary sphincter. This is to help out in the situation where you are peeing slowly and not fully emptying your bladder, and hence going to the loo more often, or going in to retention (where you can't pee at all). Was that your situation? That's not what you're saying above were your symptoms, which makes me wonder why you were given Tamsulosin.

A side effect of relaxing the smooth muscle of the internal urinary sphincter is that you could become less continent, particularly if you have urgency, it can cause urge incontinence.

Side effects are reduced blood pressure, and retrograde ejaculation (because of weakened internal urinary sphincter).

Tamsulosin won't do anything useful if you have no prostate, as all the tissues it acts on have been removed.

I've been on tamsulosin for 20 months now and I get the impression it's not as good as urology departments think it is.  It makes at best a marginal difference to my normal urine flow.   It didn't help when I had acute urine retention after HIFU, even if I took a double dose.  

It also seems to make me feel a bit sick and dizzy on getting out of bed in the morning.  I gather this is the reduced blood pressure side effect. 

Regarding urge incontinence (mentioned by Andy62)  I hadn't linked this to tamsulosin but come to think of it, I never had this symptom (as opposed to nocturia etc) before I was prescribed it.