Someone asked, in another post, if there was something to give for a cat's
nasal congestion.  My vet gave me what is, actually, eye drops but said they
work well as nose drops for cats.  Going by this one experience alone, I can
say that their nasal congestion cleared up practically overnight when I used
it.  Now, caveat here, their nasal congestion could have cleared up without
this - but it certainly didn't hurt them (they are 10 nweeks old), and on
the possibility that this is what helped them, I recommend using it.  The
bottle is a vet's sample, so I don't see a "brand" name, but here's what's
on the label:

Neomycin and Polymyxin B Sulfates and Desamethasone Opthalmic Suspension
USP.