Prelone etc. (prednisolone) is an adrenal corticosteroid that has potent anti-inflammatory properties.
Corticosteroids are synthetic drugs that closely resemble cortisol, a hormone that is naturally produced by the adrenal glands. Corticosteroids work by decreasing inflammation and reducing the activity of the immune system. Prednisolone is a derivative of Prednisone, and has been chemically changed for easy passage through the liver. Other corticosteroids include hydrocortisone (weaker in strength than prednisone); methylprednisolone (stronger than prednisone); and dexamethasone (which is extremely potent and is only used in unusual circumstances).