Comparative serum prednisone and prednisolone concentrations following administration to patients with chronic active liver disease.

Following administration of equivalent oral doses (30mg) of either prednisone or prednisolone to 5 patients with chronic active liver disease who had failed to respond to therapy, 5 patients with chronic active liver disease in remission induced by prednisone, and 7 healthy volunteers, corticosteroid concentrations were measured in both serum and urine by radioimmunoassay. Prednisone and prednisolone concentrations in the urine were very similar in all groups, regardless of the drug given. After either treatment, the peak serum concentration and area under the prednisolone serum concentration-time curve were 4 to 5 times those of prednisone. Slight differences among the 3 groups studied were seen in prednisone and prednisolone pharmacokinetics, but none was significant. It is concluded that the use of prednisone instead of prednisolone to treat chronic active liver disease can not be implicated as a cause of treatment failure. Indeed, this study suggests that either medication is effective, and this is supported by serum concentrations which suggest a rapid interconversion equilibrium between the 2 corticosteroids.