Prednisolone pharmacokinetics in cushingoid and non-cushingoid kidney transplant patients

Prednisolone pharmacokinetics and protein binding have been compared in 16 cushingoid and 46 non-cushingoid long-term kidney transplant recipients. After oral administration of 10 mg prednisolone, the cushingoid patients had a significantly higher peak prednisolone serum concentration (P less than 0.03), a longer elimination half-time (P less than 0.03), and a larger area under the time-concentration curve of total (P less than 0.01) and free (P less than 0.03) prednisolone. The apparent total body clearance of total and free prednisolone was significantly lower in the cushingoid than in the non-cushingoid patients (P less than 0.02 and less than 0.05, respectively). There was no significant difference in time of peak concentration, apparent volume of distribution or serum protein binding of prednisolone. It is suggested that the development and persistency of some cushingoid features may be related to a decreased total body clearance of prednisolone, which, in turn, may be influenced by impaired renal function.