Cyclosporine: Cyclosporine is an immune suppressing agent. It inhibits B and T lymphocyte cell activity. Its main activity is exerted by inhibiting the release of interleukin-2. Cyclosporine is used for immune-mediated diseases and also in patients receiving organ transplants. Cyclosporine is also used as a topical preparation for use in patients that have keratoconjunctivitis sicca (dry eye). Side effects include immunosuppression, vomiting, diarrhea, anorexia, gingival hyperplasia and pyoderma. The main side effects of the topical form are local irritation.
Prednisone: Prednisone is a corticosteroid that inhibits the production of prostaglandins and leukotriens to reduce inflammation. It also has immunosuppressive effects. Side effects include vomiting, diarrhea, increased thirst and urination, or iatrogenic Cushing's if prolonged high doses are used.
Cephalexin: Cephalexin is a cephalosporin antibiotic that is related to penicillin. Fewer allergic reactions are seen with this family of antibiotics than with the penicillin's. Cephalosporins are also more resistant to the enzyme beta-lactamase, making them more effective against a broader range of bacteria. Cultures are still important to find what antibiotic an organism is susceptible to. Side effects may include vomiting, diarrhea or uncommon allergic reactions.
Azathioprine (Imuran Rx) is used fairly commonly in dogs in combination with prednisone, in an effort to decrease the amount of prednisone that is necessary to control a problem or to add to the effect of prednisone when
it is not working well enough.
When these drugs are all used together, they should not be harmful to the dog.
I hope that this helps you more!