The usefulness of the steroids, such as cortisone, hydrocortisone, prednisone, and prednisolone, in the treatment of intractable asthma and other severe allergies has been definitely established. The use of these steroid hormones is limited because of their tendency to produce undesirable effects such as disturbances in mineral balance, spread of inflammatory lesions (tuberculosis and peptic ulcer), hyperglycemia, overstimulation, muscle cramps, hirsutism, moon face, and excessive appetite. These considerations and others have occasioned a continual search for anti-inflammatory steroids having less objectionable characteristics.In the search for new steroids, a compound has been synthesized which, from the results of animal experiments, appeared to offer some advantages. This steroid is methylprednisolone (Medrol) and differs from prednisolone only in the substitution of a methyl group for a hydrogen atom at the 6 alpha position. The following are the chemical formulas of prednisolone and methylprednisolone.Some of the major laboratory findings with methylprednisolone are