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→Pharmacokinetic Considerations
Corticosteroids have a short half-life, with that of cortisol being only 90 minutes. The drugs are metabolised in the [[Liver - Anatomy & Physiology|liver]], where the C4-5 double bind is reduced and conjugation with sulphate or glucuronic acid occurs. They are then excreted in the urine. Cortisone and prednisone are inactive prodrugs; upon [[Pharmacokinetics#Drug Metabolism in the Liver|liver metabolism]] they are converted to hydrocortisone and prednisolone respectively.
Corticosteroids have a short half-life, with that of cortisol being only 90 minutes. The drugs are metabolised in the [[Liver - Anatomy & Physiology|liver]], where the C4-5 double bind is reduced and conjugation with sulphate or glucuronic acid occurs. They are then excreted in the urine. Cortisone and prednisone are inactive prodrugs; upon [[Pharmacokinetics#Drug Metabolism in the Liver|liver metabolism]] they are converted to hydrocortisone and prednisolone respectively.
As with most drugs, steroids may be administered in a variety of ways. Topical steroids are appropriate for used in the eyes and ears, and on the skin. The structure of the drug can affect how useful it is topically; the C17 aliphatic side chain can influence topical absorbtion, and acetonide esters (e.g. betamethasone-17-valerate) are well absorbed from the skin but have little systemic access. Steroids are well absorbed orally, and may also be used parenterally, by inhalation and intra-articularly.
As with most drugs, steroids may be administered in a variety of ways. Topical steroids are appropriate for used in the eyes and ears, and on the skin. The structure of the drug can affect how useful it is topically; the C17 aliphatic side chain can influence topical absorption, and acetonide esters (e.g. betamethasone-17-valerate) are well absorbed from the skin but have little systemic access. Steroids are well absorbed orally, and may also be used parenterally, by inhalation and intra-articularly.
==Side Effects and Contraindications==
==Side Effects and Contraindications==