Acute dosing with methylprednisolone in normal subjects does not affect theophylline clearance

This investigation was prompted by earlier studies that suggested that short-term corticosteroids alter the clearance of theophylline. We evaluated the kinetics of theophylline administered with and without doses of oral methylprednisolone in six normal subjects. One milligram per kilogram of methylprednisolone or placebo was administered eight hours and again one hour prior to an infusion of 6 mg/kg of aminophylline. Serum levels were monitored at 15 minutes, 30 minutes, 11/2 hours, 2, 4, 6, 8, and 12-14 hours. Clearance after administration of steroids in the former was 43 +/- 7 mL/kg/h (SD) and after placebo 42 +/- 10, mL/kg/h. These data indicate that at this dose and duration methylprednisolone seems to have no statistical or clinically significant impact upon the clearance of theophylline in normal subjects.