Pharmacokinetics of Prednisone in Adults

This is a monocentric study, in the Internal Medicine Service of Cochin Hospital, Paris. Our main objective is to determine the pharmacokinetic properties of prednisone, secondary objectives are to determine the covariates affecting the prednisone pharmacokinetics and the relationship between glucocorticoid exposition levels and their side effects. The investigators will use a prospective, observational, population pharmacokinetic approach. 100 patients starting a prednisone treatment \>7,5mg/d for an expected period \>3 months will be recruited and followed over 6 months.