Oral Corticosteroids: Update on Clinically Relevant Drug Interactions

Oral corticosteroids arecommonly used inambulatory patientsas short- or long-termtherapy for a numberof diseases. For example, patientswith acute exacerbations of asthmaor chronic obstructive pulmonary diseaseare routinely given 1- to 2-weekcourses of prednisone, methylprednisolone,or another oral corticosteroid.In addition, oral corticosteroidsare used as maintenance therapy inpatients with such conditions assystemic lupus erythematosus, sarcoidosis,and post-organ transplantcomplications.Several drug interactions associatedwith oral corticosteroids are clinically relevant. Drugs that maydecrease the response to oral corticosteroidsare shown in Table 1,and agents that may increase the responseare summarized in Table 2.Note that inhibitors of drug metabolismhave an effect on some, but notall, of the oral corticosteroids.A report suggests that highdoses of methylprednisolone may enhancethe response to oral anticoagulants.1 Therefore, in patients receivingoral anticoagulant therapy, closermonitoring of prothrombin time/INRis warranted as methylprednisoloneis initiated, during corticosteroidtreatment, and as it is discontinued.Further study of this potential interactionis needed.¹grapefruit juice increases the peakplasma concentrations of methylprednisoloneby 27%; however, the clinicalsignificance is likely minor becauselarge amounts of grapefruit juice arerequired to produce this effect.²

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