Sinus infectiion and antibiotics

I have had one sinus infection after another for a couple of years.  As I have pretty bad asthma too, they are a serious thing, and I try to take care of them as soon as possible or else I end up in hospital with asthma problems.  This is my question.  Isn't there a way we can figgure out WHAT antibiotic works without experimenting every time?  I swear I have been on most of the common antibiotics because every few months I get a new infection, and the old antibiotic doesn't work.  And I am NOT one of those people who forgets to take my antibiotic right. I finish them every time.  I have tried everything from saline sprays to antihistamines to steroid sprays.  Can my asthma meds like prednisone make it worse?  Becuse every time I get a infection I end up on prednisone pills too along with everything else.  Do these make the antibiotic less effective?

[National Jewish]

This is obviously a very difficult and frustrating problem for you. There are several important questions to be addressed.
1)Why do you get so many sinus infections? There are probably a variety of reasons possible for this. The most likely one is that the sinuses do not drain in a proper way and thus remain a source of infection even after weeks of antibiotics.
2)Which antibiotics will work? This is a very difficult question. There are several stronger antibiotics that will work for a while. However, after you have had several courses of these, they are not as effective either. Without putting a needle directly into the sinus to get a culture, it will still be a lot of "trial and error" with the antibiotics.
3)Do your asthma medications make it worse? While this is possible, it is not as likely. There are some people who develop fungal sinus infections due to taking prednisone. However, this is not common.
I would suggest directly approaching the sinus situation as the first priority.
Good luck