Prednisone is a synthetic corticosteroid drug that is particularly effective as an immunosuppressant drug. It is used to treat certain inflammatory diseases (such as moderate allergic reactions) and (at higher doses) some types of cancer, but has significant adverse effects. Because it suppresses the immune system, it leaves patients more susceptible to infections. Prednisone is used for many different indications including: asthma, COPD, CIDP, rheumatic disorders, allergic disorders, ulcerative colitis and Crohn's disease, adrenocortical insufficiency, hypercalcemia due to cancer, thyroiditis, laryngitis, severe tuberculosis, urticaria (hives), lipid pneumonitis, pericarditis, multiple sclerosis, nephrotic syndrome, lupus, myasthenia gravis, poison oak exposure, and as part of a drug regimen to prevent rejection post organ transplant.