Prostate problems can refer to more than one thing as I'm sure you know. webmd.com will have a lot of good info on these things.
First is prostate cancer. This is life threatening and is why any hint of prostate problems should not be ignored. If it is caught early, it can be treated as my dad was, and this is much easier on the body than the old treatments. On my dad, they implanted tiny targets into his prostate, then used those targets for the radiation treatments. IIRC, it was 6 months of treatments he underwent. The only side effects he said he had was that he couldn't get too far away from the bathroom for a day or two after a treatment. This worked perfectly for him.
If you don't catch prostate cancer early, you may need surgery, and I understand that some surgeries can be sexually disabling. I'm sure they are much better at this now than they were 20 years ago, but a friend of ours had such a disabling surgery. Bottom line: Don't wait!!!
Enlarged prostate is another situation entirely. One of my brothers and I developed this much earlier in life than men normally do. This is also very easily treatable, but you have to be seen for it - the medication doesn't do you any good in the bottle. This condition is so frustrating because you always feel like you need to pee, when you go, sometimes you can't void, sometimes it may take 10 minutes to void a full bladder ... peeing gives a very underrated relief, believe me.
Some of the meds may have a little bit of a side effect. You can find these listed and even discussed on webmd.com. I am on flo-max (or a generic version of it). Flo-max can cause absent ejaculation in some men. It causes this with me. What this means is that a man can build to orgasm and can have a good orgasm, but he doesn't ejaculate when he has the orgasm. However; this effect only lasts from about 1 - 18 hours after I actually take the pill. Since it is something I only take once/day, it's pretty easy to time this by taking it at bedtime each day. Ejaculation with orgasm is probably more important to my wife than it is to me, but whomever it is important to, it is something I want to work around if possible. Since our love-making normally happens in the evening, we have plenty of time to have sex with full ejaculation if I take the flo-max at bedtime. In those times when we want to make love in the morning, we still do and it doesn't cause any problems, but my wife knows I will not ejaculate when I orgasm. When she's content that I enjoyed it even though I didn't ejaculate, she relaxes and can enjoy morning sessions, too.
The bottom line, though, is that he needs to get to the doctor, and waiting isn't the answer. Some prostate problems can be life-threatening, and they need to be diagnosed early and treated agressively.