ABSORPTION OF ACETATES OF HYDROCORTISONE, Δ1-HYDROCORTISONE AND CORTISONE FROM THE JOINT CAVITY INTO THE CIRCULATION

Abstract

Absorption of the acetates of hydrocortisone, [DELTA] 1-hydrocortisone and cortisone from the synovial cavity of the knee into the circulation was studied in 28 patients suffering from rheumatoid arthritis. A comparison was also made of the oral and intraarticular absorption of hydrocortisone acetate, by administering equal doses by both routes to a group of patients. The acetates of hydrocortisone, [DELTA]1 -hydrocortisone and cortisone were found to be absorbed from the joint cavity into the circulation in significant quantities. The maximal free plasma 17-hydroxycorticosteroid levels were reached within three to six hours after the injection. At twenty-four hours there were still detectable amounts of injected steroids in the circulation in most of the cases. No major differences could be observed in the plasma concentrations of free 17-hydroxycorticosteroids after intraarticular administration of equal doses of the 3 steroids. Individual variations in each group were, however, pronounced. The elevation of conjugated plasma 17-hydroxycorticosteroids after intra-articular injection of cortisone acetate was much greater than after the injection of hydrocortisone acetate. No significant elevation in conjugated plasma 17-hydroxycorticosteroids could be demonstrated after intra-articular injection of [DELTA]1-hydrocortisone acetate. The absorption of hydrocortisone acetate into the blood after oral administration was much greater and more rapid than after intraarticular injection. The disappearance of orally administered hydrocortisone acetate from the plasma was also more rapid than that of the intra-articularly injected steroid.