Concerns about Atopica

So my cat Grimm is a problem child, more so than Gracie and Gandalf are, and he tends to get sick more often and for longer than the others. In the beginning of this year all three of my babies had Upper Rwspitory Infections that the vet prescribed an antibiotic for. It cleared up within a week for all three cats. Months later Grimm seemed to be sick again, wheezing, hacking, sneezing with snot and drool, and snoring while he sleeps. My concern is the possibility of allergies or asthma, since none of these symptoms occurred during the URI earlier this year. The vet, however, thinks it is the URI coming back and prescribed prednisone, a steroid, which doesn't seem to be working after 2 weeks of dosage according to the instructions. Actually,the sneezing and snot has gotten worse. Now the vet wants to switch to Atopica, but after having read and researched the medication, I'm worried that it is going to make Grimm incredibly sick for no reason. Atopica, from what I've read, is for the treatment and control of feline allergen dermatitis, or skin issues from allergies such as sores from scratching, chewing, and licking due to itchiness. I've expressed to my vet that Grimm has none of these symptoms or behaviors, nothing has shown up on his skin or fur, he's eating like normal and is not lethargic at all....my concern is that this medicine is not right for his issues and could cause him discomfort and possibly worse issues and not be helpful to his current issues.

I would say if you're not comfortable with what your Vet is telling you, get a second opinion.  Is there another Vet nearby you could take Grimm to?  Or if you don't want to take HIM out again, possibly you could at least take his records to another Vet to get another opinion ? 

I have heard of Atopica mainly used for skin allergies too, rather than what sounds like seasonal allergies or a cold.

I am currently in the processing of weening my cat off prednisolone to Atopica for immune suppression. Atopica is marketed for skin allergies but it is used in other cases when a steroid may not be the right choice.

My kitty has an auto-immune disease and started to develop very serious side effects from the pred. Between 4 different vets (UGA Vet School, IM Vet, my regular vet and a vet I called for a second opinion) we had to try something different.

It is a liquid, expensive and smells horrible (I can only imagine what it tastes like) but it has less/different side effects than steroids. All medications have side effects but there might be a good reason your vet suggested the Atopica over pred.