Corticosteroids: clinical pharmacology
The naturally occurring adrenocortical steroids (hydrocortisone, cortisone) have both anti-inflammatory (glucocorticoid) and salt-retaining (mineralocorticoid) properties. They are used as replacement therapy in adrenocortical deficiency states.
Synthetic corticosteroid compounds (eg prednisolone) are mainly used for their anti-inflammatory properties. Dexamethasone, methylprednisolone and betamethasone are synthetic compounds with marked glucocorticoid activity and an absence of significant salt-retaining activity. These agents are used for their potent anti-inflammatory effects.
Fludrocortisone has been developed to maximise mineralocorticoid activity.
Orally administered corticosteroids are well absorbed; however, cortisone and prednisone are prodrugs that require hepatic activation. They therefore may not be efficacious in patients with liver impairment. Prednisone is a prodrug of prednisolone. It is converted rapidly to prednisolone if liver function is normal. Unless liver function is severely impaired, prednisone and prednisolone are considered to be clinically equivalent and can be used interchangeably. In these guidelines, whenever prednisolone is recommended, an equal dose of prednisone can be substituted. Prednis(ol)one refers to either prednisolone or prednisone.
Corticosteroids have biological half-lives that are 2 to 36 times longer than their plasma half-lives because of their complex mechanism of action. The onset of biological effects lags behind peak plasma levels.
See Use in dermatology for information on the use of topical corticosteroids.
The major limiting factor in the use of corticosteroids is the development of extensive, dose-related adverse effects
Comments
Post a Comment