Coadministration is expected to decrease concentrations of darunavir and cobicistat and to increase concentrations of methylprednisolone. Co-administration with systemic corticosteroids that induce CYP3A may result in loss of therapeutic effect and development of resistance to darunavir/cobicistat. Consider alternative corticosteroids. Co-administration with corticosteroids (all routes of administration) of which exposures are significantly increased by strong CYP3A inhibitors can increase the risk for Cushing’s syndrome and adrenal suppression. Alternative corticosteroids including beclomethasone, prednisone and prednisolone (for which PK and/or PD are less affected by strong CYP3A inhibitors relative to other steroids) should be considered, particularly for long term use.