Information about Corticosteroids
The corticosteroids are a group of chemically related natural hormones and synthetic agents that resemble the human adrenal hormone cortisol and have potent antiinflammatory and immunosuppressive properties and are widely used in medicine. Corticosteroid therapy is associated with several forms of liver injury, some due to exacerbation of an underlying liver disease and some that appear to be caused directly by corticosteroid therapy. This discussion will cover eight agents: betamethasone, cortisone, dexamethasone, hydrocortisone, methylprednisolone, prednisolone, prednisone, and triamcinolone.
Mechanism of action of Corticosteroids
The corticosteroids are hormones that have glucocorticoid (cortisol-like) and/or mineralocorticoid (aldosterone-like) activities and which are synthesized predominantly by the adrenal cortex. In clinical practice, the term “corticosteroids” usually refers to the glucocorticoids and are represented by a large group of natural or synthetic steroid compounds that have varying potency, durations of action and relative glucocorticoid (measured by antiinflammatory activity) vs mineralocorticoid (measured by sodium retention) activities. Cortisol and the corticosteroids act by engagement of the intracellular glucocorticoid receptor, which then is translocated to the cell nucleus where the receptor-ligand complex binds to specific glucocorticoid-response elements on DNA, thus activating genes that mediate glucocorticoid responses. The number of genes modulated by corticosteroids are many and the effects are multiple and interactive with other intracellular pathways. Thus, the effects of corticosteroids on inflammation and the immune system cannot be attributed to a single gene or pathway. The potent antiinflammatory and immunosuppressive qualities of the corticosteroids have made them important agents in the therapy of many diseases. Corticosteroids are available in multiple forms, including oral tablets and capsules; powders and solutions for parenteral administration; topical creams and lotions for skin disease; eye, ear and nose liquid drops for local application; aerosol solutions for inhalation and liquids or foams for rectal application. Representative corticosteroids (and the year of their approval for use in the United States) include cortisone (1950), prednisone (1955), prednisolone (1955), methylprednisolone (1957), dexamethasone (1958), betamethasone (1961), and hydrocortisone (1983). All are available in generic forms. In this website, only the oral and intravenous formulations of corticosteroids are described and they are discussed together with common list of references and representative case reports.
The corticosteroids are used widely in medicine largely for their potent antiinflammatory and immunosuppressive activities. The clinical conditions for which corticosteroids are used include, but are not limited to: asthma, systemic lupus erythematosis, rheumatoid arthritis, psoriasis, inflammatory bowel disease, nephritic syndrome, cancer, leukemia, organ transplantation, autoimmune hepatitis, hypersensitivity reactions, cardiogenic and septic shock, and, of course, glucocorticoid deficiency diseases such as in Addison’s disease and panhypopituitarism.
Corticosteroids are used in several liver diseases, most commonly in autoimmune hepatitis for which they have been shown to improve outcome and survival. Corticosteroids are also used after liver transplantation to prevent rejection. An important element in managing these liver diseases and conditions is to maintain the dose of corticosteroids at the lowest effective level. The adverse effects of long term corticosteroid therapy (which are rarely hepatic) are still major causes of morbidity and even mortality in these conditions.
Prednisone, prednisolone, methylprednisone and triamcinolone are the most commonly used oral agents as they are inexpensive, rapid in onset, intermediate in duration of action and have potent glucocorticoid with minimal mineralocorticoid activities, at least as compared to cortisone and hydrocortisone. Betamethasone and dexamethasone have greater glucocorticoid potency and less aldosterone-like activity than prednisone, but have a longer duration of action, and they are mostly used in topical or liquid forms for local application and in injectable forms for severe hypersensitivity reactions and inflammation. Methylprednisone and hydrocortisone are most commonly used for intravenous administration, typically given in emergency or critical situations in which rapid and profound immunosuppression or antiinflammatory activity is needed.
The table below provides the major forms of corticosteroids and their relative glucocorticoid and mineralocorticoid activity and equivalent daily doses.
Cortisone (kor' ti sone) is a short acting glucocorticoid that is used for therapy of adrenal insufficiency and for treatment of allergic and inflammatory conditions. Cortisone is available in generic forms in tablets of 25 mg, which is considered a daily physiologic dose in adults. Cortisone has both glucocorticoid and mineralocorticoid properties.
Hydrocortisone (hye droe kor' ti sone) is a rapid and short acting glucocorticoid that is used for therapy of adrenal insufficiency and in treatment of allergic and inflammatory conditions. Hydrocortisone has the same chemical structure as cortisol and thus most closely resembles the human adrenal hormone. Hydrocortisone is available in generic forms in tablets of 5, 10 and 20 mg, with 20 mg being considered a daily physiologic dose in adults. Hydrocortisone is also available in multiple forms in solution for oral, rectal, topical or parenteral administration. A major use of intravenous hydrocortisone is in the acute therapy of severe hypersensitivity reactions and shock. Hydrocortisone has both glucocorticoid and mineralocorticoid properties.
Prednisone (pred' ni sone) is a synthetic, intermediate acting glucocorticoid that is widely used in the therapy of severe inflammation, autoimmune conditions, hypersensitivity reactions and organ rejection. Prednisone is converted to prednisolone, its active form, in the liver. Prednisone is available in multiple generic forms in tablets of 1, 2.5, 5, 10, 20 and 50 mg and as oral solutions. Four times more potent that cortisol, prednisone is used in varying doses, with 5 mg daily being considered physiologic doses in adults.
Prednisolone (pred nis' oh lone) is a synthetic, intermediate acting glucocorticoid that is widely used in the therapy of severe inflammation, autoimmune conditions, hypersensitivity reactions and organ rejection. Prednisolone is available in multiple generic forms in tablets of 5, 10, 15 and 30 mg and in several forms for systemic administration. Four times more potent that cortisol, prednisolone is used in varying doses, with 5 mg daily being considered physiologic doses in adults.
Methylprednisolone (meth il pred nis' oh lone) is a synthetic, intermediate acting glucocorticoid that widely used in the therapy of severe inflammation, autoimmune conditions, hypersensitivity reactions and organ rejection. Methylprednisolone is available in multiple forms in tablets of 2, 4, 8, 16 and 32 mg generically and under the brand name of Medrol and in Medrol Dosepaks (21 tablets of 4 mg each). Injectable forms of methylprednisolone are also available generically and under brand names of Solu-Medrol and Depo-Medrol. Five times more potent that cortisol, methylprednisolone is used in varying doses, with 4 mg daily being considered physiologic doses in adults. Methylprednisolone has minimal mineralocorticoid activity.
Triamcinolone (trye am sin' oh lone) is a synthetic, long acting glucocorticoid that is used in topical solutions and aerosols for therapy of allergic and hypersensitivity reactions and control of inflammation as well as in parenteral formulations for therapy of hypersensitivity reactions, shock and severe inflammation. Oral forms of triamcinolone include tablets of 4 and 8 mg and oral syrups. Parenteral forms for injection are available under various generic and trade names including Aristocort and Kenacort. Triamcinolone is five times more potent than cortisol in its glucocorticoid activity, but has minimal mineralocorticoid activity.
The table below provides the major forms of corticosteroids and their relative glucocorticoid and mineralocorticoid activity and equivalent daily doses.
|RELATIVE POTENCIES OF CORTICOSTEROIDS|
|AGENT||GLUCOCORTICOID ACTIVITY||MINERALOCORTICOID ACTIVITY||EQUIVALENT ORAL OR INTRAVENOUS DOSE|
Dexamethasone (dexa meth' a sone) is a synthetic, long acting glucocorticoid that is used parenterally as therapy of severe hypersensitivity reactions, shock and control of severe inflammation as well as in topical, otic, ophthalmologic solutions, aerosols and lotions or creams for local therapy of allergic reactions and inflammation. Dexamethasone is available in multiple forms for injection under various generic and trade names including Decadron. Dexamethasone is 25 times more potent than cortisol in its glucocorticoid activity, but has minimal mineralocorticoid activity.
Betamethasone (bay ta meth' a sone) is a synthetic, long acting glucocorticoid that used in parenteral forms for therapy of allergic and hypersensitivity reactions and control of severe inflammation. Betamethasone is available in solution for injection under the trade name of Celestone and in multiple generic forms as syrups and effervescent tablets for oral use, edemas and foams for rectal use, aerosols for nasal and respiratory use, and creams and lotions for topical use. Betamethasone is 25 times more potent than cortisol in glucocorticoid activity, but has minimal mineralocorticoid activity.
Liver safety of Corticosteroids
Corticosteroids have multiple adverse side effects, due to their multiplicity of actions affecting virtually all organs. Long term use has very profound effects on growth and can lead to cataracts, glaucoma, opportunistic infections, thinning of the skin, weight gain and redistribution of fat, insulin resistance and diabetes, hypertension, headache, psychiatric problems, sodium retention and peripheral edema; all of the clinical features of Cushing syndrome.
Corticosteroids also have major effects on the liver, particularly when given long term and in higher than physiologic doses. Glucocorticoid use can result in hepatic enlargement and steatosis or glycogenosis. Corticosteroids can trigger or worsen nonalcoholic steatohepatitis. Long term use can also exacerbate chronic viral hepatitis. Importantly, treatment with corticosteroids followed by withdrawal or pulse therapy can cause reactivation of hepatitis B and worsening or de novo induction of autoimmune hepatitis, both of which can be fatal. Finally, high doses of intravenous corticosteroids, largely methylprednisolone, have been associated with acute liver injury which can result in acute liver failure and death. Thus, the hepatic complications of corticosteroids usually represent the worsening or triggering of an underlying liver disease and rarely are the result of drug hepatotoxicity.
Corticosteroid therapy can cause hepatic steatosis and hepatic enlargement, but this is often not clinically apparent, particularly in adults. This effect can occur quite rapidly and is rapidly reversed with discontinuation. High doses and long term use has been associated with the development or exacerbation of nonalcoholic steatohepatitis with elevations in serum aminotransferase levels and liver histology resembling alcoholic hepatitis with steatosis, chronic inflammation, centrolobular ballooning degeneration and Mallory bodies (Case 1). However, symptomatic or progressive liver injury from corticosteroid induced steatohepatitis is uncommon. Furthermore, corticosteroids may act to worsen an underlying nonalcoholic fatty liver disease rather than causing the condition de novo. The worsening may be due to direct effects of glucocorticoids on insulin resistance or fatty acid metabolism or may be the result of weight gain which is common with long term corticosteroid therapy. While simple steatosis induced by corticosteroids is rapidly reversible, steatohepatitis can be slow to resolve upon withdrawal of corticosteroids.
Corticosteroids in high doses can also cause hepatic glycogenosis, in which liver cells exhibit a homogenous appearance and stain strongly for glycogen (using PAS staining with and without diastase). Glycogenosis can also be associated with hepatomegaly (in children) and elevations in serum aminotransferase levels with minimal or no change in alkaline phosphatase or bilirubin levels. Glycogenosis is usually asymptomatic and does not appear to progress to chronic liver injury, cirrhosis or acute liver failure. While glycogenosis has been described largely in patients with poorly controlled type 1 diabetes, it also can occur acutely in patients started on high dose corticosteroids.
An important complication of corticosteroid therapy is the worsening of an underlying chronic viral hepatitis. In chronic hepatitis B, corticosteroids can induce increases in viral replication and serum hepatitis B virus (HBV) DNA levels while decreasing serum aminotransferase levels. Eventually, however, the increase in viral replication can worsen the underlying liver disease. Exacerbation of hepatitis becomes particularly evident when corticosteroids are withdrawn or lowered to physiological levels. As the immune system recovers, hepatitis worsens and serum aminotransferase levels can rise to greater than 10- to 20-fold elevated usually accompanied by a prompt decrease in HBV DNA levels. This flare of disease following withdrawal of corticosteroids can be severe and result in acute liver failure or significant worsening of chronic hepatitis and development of cirrhosis (Case 2). Indeed, even patients with the “inactive carrier states” (as shown by the presence of HBsAg in serum without HBeAg or detectable HBV DNA or any elevation in serum aminotransferase levels) can suffer severe reactivation of disease and acute liver failure as a result of a short course of high dose corticosteroids as occurs with cancer chemotherapy or with treatment of severe autoimmune conditions or even asthma, hay fever or allergic dermatitis. Reactivation of hepatitis B can be prevented by prophylactic use of antiviral therapy during the period of immunosuppression, but even this may not prevent some degree of liver injury.
Corticosteroids also appear to worsen the course of chronic hepatitis C, although in a less dramatic fashion than in chronic hepatitis B. Corticosteroid therapy leads to a rise in hepatitis C virus (HCV) RNA levels which may eventually cause worsening of the underlying liver disease. Chronic hepatitis C appears to be more severe and is particularly difficult to manage in patients receiving chemotherapy or immunosuppression, and corticosteroids are believed to be a major factor in this effect. Thus, corticosteroids should be avoided if possible in patients with underlying chronic viral hepatitis.
Corticosteroids are used in the therapy of autoimmune hepatitis and, therefore, are likely to be beneficial rather than harmful in patients with this disease. The difficulty arises when corticosteroids are stopped, which can cause a rebound exacerbation of the autoimmune hepatitis that is often severe and can be fatal. Importantly, there have been multiple reported instances of de novo appearance of severe autoimmune hepatitis in patients who received a short course or pulse of corticosteroids for another, unrelated condition (such as asthma or allergic reactions). In these situations, a mild and subclinical autoimmune hepatitis was likely present before corticosteroids were started, and the suppression of the disease followed by immune rebound caused the clinical presentation of the condition. These patients generally respond to restarting corticosteroids, but may require long term if not life long immunosuppressive treatment thereafter.
Finally, there have been several reports of an acute hepatitis-like liver injury arising after a short, high dose course of intravenous methylprednisolone that can be severe and even fatal, and in which viral hepatitis and autoimmune hepatitis cannot be clearly implicated (Case 3). The cause of this apparent hepatotoxicity is not known, but it may represent severe autoimmune hepatitis triggered by the sudden profound immunosuppression and subsequent immune reconstitution. Importantly, symptoms and jaundice develop 2 to 4 weeks after stopping methylprednisolone and the pattern of serum enzyme elevations is typically hepatocellular. These episodes are usually symptomatic and can be severe. Immunoallergic manifestations are uncommon and autoantibodies may not be present. Several instances have resulted in acute liver failure resulting in death or need for emergency liver transplantation. Restarting corticosteroids may be appropriate in this situation, but it has not been evaluated systematically and many instances have resolved spontaneously. Recurrence of injury, often in a more rapid and severe form, arises upon reexposure to high dose pulse methylprednisolone.
Drug class for Corticosteroids