Proctosedyl suppositories for hemoroids really help as do diclofenac suppositories. Ibruprofen & Paracetamol (at the same time-ok as different types-always with food ), Quercitin, bromelain & squatting on toilet seat whilst defacating as opposed to sitting .
You might try acupuncture - it works for some people. In my case I reckon it gives me a little relief most times. Another thing which I found effective was tricyclic antidepressants. These are the 'old-style' antidepressants which for some reason can act as painkillers. The dose you need is much less than for people suffering from depression, and they may take two or three weeks to start working, but they had a positive effect for me. In particular, as they tend to make you drowsy then I found I was getting a better night's sleep, which is always helpful if you have chronic pain. I hope you can find something to help.
It raises the larger question of research into painkillers. As we're told that prostatitis is not life threatening, but a question of pain control, I'd really like to know what research is being done into painkillers that work for this type of pain. It would be wonderful, not just for prostatitis sufferers, but for all those people with a variety of conditions for which there is no effective pain relief.
Man when the pain dont let me live, i was taking Tramal 200mg twice a day... surelly gives you a relief but you have to be aware to drive, because cause some diziness and fatigue, together (like Nik told you) with diclofenac suppositories. Here in Poland i was using something that helps me a lot, is called "Betaprostan" and the composition is betasitosterol 200 mg, maybe you can found something simillar in your country.
I was taking really, really hot baths, that helps me too.