Corticosteroids

Glucocorticoids are endogenous (hydrocortisone) and synthetic (prednisolone, metylprednisolone, dexamethasone) steroid hormones with metabolic, anti-inflammatory, and immunosuppressive effects. They bind to specific intracellular receptors and translocate into the nucleus, where they regulate gene expression in a tissue-specific manner.

Corticosteroids have multiple indications including:

  • Replacement in adrenal suppression or other cortisol-deficient states
  • Autoimmune disorders
  • Anaphylaxis and atopic disorders, including asthma
  • Hypercalcaemia
  • Chemotherapy
  • Immunosupression following transplantation

Common Features

System Effect
Resp ↑ Bronchial smooth muscle response to circulating catecholamines, ↓ airway oedema
CVS ↑ Inotropy, ↑ vascular smooth muscle response to circulating catecholamines (↑ receptor expression), ↑ BP secondary to mineralocorticoid effects
CNS Mood changes, sleep disturbance, psychosis
MSK Atrophy, thinning of skin
Renal Glycosuria, Na+ and fluid retention (mineralocorticoid effect), hypokalaemia
GIT Gastric ulceration
Metabolic ↑ Gluconeogenesis, diabetes, ↑ protein catabolism, fat redistribution, adrenal suppression (negative feedback on ACTH), ↑ lipolytic response to circulating catecholamines
Immune ↓ Transudate production, ↓ production of inflammatory mediators, ↓ macrophage function, ↓ transport of lymphocytes, ↓ T-cell function, ↓ antibody production, ↑ susceptibility to infection,
Toxic Effects Relative steroid deficiency in adrenal suppressed individuals with infection or surgery

Comparison of Corticosteroids

Property Hydrocortisone Prednisolone Methylprednisolone Dexamethasone
Route of Administration IV/PO PO PO/IV/IM IV
Relative Dose Equivalents 100mg 25mg 20mg 4mg
Absorption 50% PO bioavailability 100% PO bioavailability 60% PO bioavailability
Distribution Variable protein binding depending on concentration, VD 0.5 L.kg-1 Variable protein binding depending on concentration, VD 0.5 L.kg-1 VD 1 L.kg-1
Metabolism Hepatic Hepatic Hepatic Hepatic
Elimination Elimination t0.5 is 2 hours Elimination t0.5 is 3 hours Elimination t0.5 is 3 hours Elimination t0.5 is 4 hours
Relative mineralocorticoid effect +++ ++ + +

References

  1. Peck TE, Hill SA. Pharmacology for Anaesthesia and Intensive Care. 4th Ed. Cambridge University Press. 2014.
  2. Smith S, Scarth E, Sasada M. Drugs in Anaesthesia and Intensive Care. 4th Ed. Oxford University Press. 2011.
  3. Nieman LK, Lacroix A, Martin KA. Pharmacologic use of glucocorticoids. In: UpToDate, Post, TW (Ed), UpToDate, Waltham, MA, 2017.
  4. Petkov V. Essential Pharmacology For The ANZCA Primary Examination. Vesselin Petkov. 2012.
Last updated 2017-09-16

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