Your child needs to take one of these medicines: prednisone, prednisolone, or dexamethasone. This information sheet explains what these. Prednisone, 5 mg, 4, Dexamethasone, mg, 25, 0 Asare K. Diagnosis and treatment of adrenal insufficiency in the critically ill patient. Decadron (dexamethasone) and prednisone are corticosteroids used to treat arthritis, skin, blood, kidney, eye, thyroid, intestinal disorders, severe allergies, and asthma. Side effects of Decadron and prednisone that are similar include nausea, vomiting, headache, acne, trouble.