Corticosteroids have been used as drug treatment for some time. Lewis Sarett of Merck & Co. was the first to synthesize cortisone, using a complicated 36-step process that started with deoxycholic acid, which was extracted from ox bile .  The low efficiency of converting deoxycholic acid into cortisone led to a cost of US $200 per gram. Russell Marker , at Syntex , discovered a much cheaper and more convenient starting material, diosgenin from wild Mexican yams . His conversion of diosgenin into progesterone by a four-step process now known as Marker degradation was an important step in mass production of all steroidal hormones, including cortisone and chemicals used in hormonal contraception .  In 1952, . Peterson and . Murray of Upjohn developed a process that used Rhizopus mold to oxidize progesterone into a compound that was readily converted to cortisone.  The ability to cheaply synthesize large quantities of cortisone from the diosgenin in yams resulted in a rapid drop in price to US $6 per gram, falling to $ per gram by 1980. Percy Julian's research also aided progress in the field.  The exact nature of cortisone's anti-inflammatory action remained a mystery for years after, however, until the leukocyte adhesion cascade and the role of phospholipase A2 in the production of prostaglandins and leukotrienes was fully understood in the early 1980s.
After a favorable response is noted, the proper maintenance dosage should be determined by decreasing the initial drug dosage in small decrements at appropriate time intervals until the lowest dosage which will maintain an adequate clinical response is reached. It should be kept in mind that constant monitoring is needed in regard to drug dosage. Included in the situations which may make dosage adjustments necessary are changes in clinical status secondary to remissions or exacerbations in the disease process, the patient’s individual drug responsiveness and the effect of patient exposure to stressful situations not directly related to the disease entity under treatment. In this latter situation it may be necessary to increase the dosage of dexamethasone sodium phosphate injection, USP for a period of time consistent with the patient’s condition. If after a long-term therapy the drug is to be stopped, it is recommended that it be withdrawn gradually rather than abruptly.