Rectally administered prednisolone--evidence for a predominantly local action.

Plasma prednisolone levels have been compared in healthy volunteers and in patients suffering from idiopathic proctocolitis after the administration of standard retention enemata containing either prednisolone-21-phosphate or prednisolone metasulphobenzoate sodium. The levels were significantly lower after the latter, irrespective of the presence or degree of activity of the disease. Prednisolone metasulphobenzoate appeared to be as effective as the 21-phosphate ester for the treatment of proctocolitis in the few patients where the two drugs were compared. It seems possible that the beneficial effect of the form of therapy is exerted predominantly locally, rather than by systemic action.