Corticosteroid

Corticosteroids are steroid hormones produced by the adrenal cortex and medicines that reproduce or modify their actions. Their two principal groups are glucocorticoids, exemplified by cortisol, and mineralocorticoids, exemplified by aldosterone. Glucocorticoids influence metabolism, stress responses, and inflammation, whereas mineralocorticoids regulate sodium and potassium balance and help maintain blood pressure. (niddk.nih.gov)

Corticosteroid medicines have important roles in hormone replacement and in the treatment of inflammatory and immune-mediated diseases. In clinical usage, “corticosteroid” frequently refers specifically to glucocorticoid drugs, such as prednisone, although the broader class also includes mineralocorticoid preparations. Their effects depend on the compound, formulation, route of administration, and duration of exposure; systemic glucocorticoid treatment can also suppress the body's own cortisol production. Understanding the class therefore requires distinguishing normal hormonal functions from pharmacological effects and examining both therapeutic applications and adverse effects. (dailymed.nlm.nih.gov)

Definition, classification, and chemical structure

Corticosteroids are steroid hormones produced by the adrenal cortex and pharmaceutical compounds that reproduce or modify their activities. Endogenous corticosteroids include cortisol and aldosterone; pharmaceutical preparations include naturally occurring hormones manufactured as medicines, such as hydrocortisone, and synthetic derivatives such as prednisone. The class comprises two principal functional groups: glucocorticoids and mineralocorticoids. In clinical descriptions of anti-inflammatory treatment, “corticosteroid” often refers specifically to a glucocorticoid, rather than to every member of the broader class. This narrower usage reflects the widespread use of glucocorticoid medicines to suppress inflammation and immune responses; mineralocorticoid preparations serve a distinct role in hormone replacement. (cancer.gov)

The distinction between the two groups concerns their predominant biological activities, not separate chemical frameworks. Cortisol, the principal physiological example of a glucocorticoid, contributes to glucose regulation, metabolism, and responses to physiological stress, while also limiting inflammation. Aldosterone exemplifies mineralocorticoid activity through its contribution to sodium and potassium balance and, consequently, salt–water balance and blood pressure. These categories are not mutually exclusive at the level of an individual medicine: hydrocortisone has both glucocorticoid and salt-retaining effects, whereas fludrocortisone possesses strong mineralocorticoid activity together with glucocorticoid activity. Its pharmaceutical use is chiefly directed toward the mineralocorticoid component. (niddk.nih.gov)

The shared steroid nucleus contains 17 carbon atoms arranged in four fused rings: three six-membered rings, designated A, B, and C, and one five-membered ring, D. The carbon numbering of this nucleus provides a common language for describing structural substitutions. The corticosteroid structures represented by hydrocortisone and prednisone have a 21-carbon pregnane framework, including two methyl groups and a two-carbon side chain attached at carbon 17. Differences in double bonds, oxygen-containing groups, and additional substituents distinguish individual compounds without replacing the underlying steroid nucleus. (calslab.snu.ac.kr)

Prednisone illustrates modification of both unsaturation and oxygen functionality. Its molecular formula is $\mathrm{C_{21}H_{26}O_5}$, and its molecular mass is 358.44. Compared with hydrocortisone, it has an additional double bond between carbons 1 and 2 and a carbonyl group at carbon 11 instead of an $11\beta$-hydroxyl group; both retain the double bond between carbons 4 and 5. Fludrocortisone illustrates halogen substitution: its structure contains fluorine at carbon 9 while retaining the $11\beta$-hydroxyl group. In fludrocortisone acetate, the hydroxyl group at carbon 21 is additionally esterified with acetate. Thus, fluorination and esterification describe different structural changes within the same preparation. (dailymed.nlm.nih.gov)

Budesonide has a cyclic 16,17-acetal formed with butyraldehyde, adding a further ring and increasing the molecular formula to $\mathrm{C_{25}H_{34}O_6}$, with a molecular mass of 430.5. It is supplied as a mixture of the $22R$ and $22S$ epimers: molecules differing in configuration at carbon 22 while retaining the same connectivity. Prednisone, fludrocortisone acetate, and budesonide therefore illustrate double-bond modification, halogen substitution, ester formation, and cyclic-acetal formation within the corticosteroid family. These chemical descriptions identify the compounds; they do not, by themselves, establish equivalent clinical potency or interchangeability. (dailymed.nlm.nih.gov)

Adrenal synthesis and regulation of secretion

Corticosteroid production is organized by zones within the cortex of the adrenal gland. The outer zona glomerulosa produces aldosterone; the middle zona fasciculata is the principal source of cortisol. The innermost zona reticularis chiefly produces adrenal androgens, including dehydroepiandrosterone (DHEA), DHEA sulfate, and androstenedione, although it also contributes some glucocorticoid production. These functional differences reflect zone-specific expression and activity of steroidogenic enzymes, rather than different starting substrates. (ncbi.nlm.nih.gov)

All adrenal steroids originate from cholesterol. Steroidogenic acute regulatory protein (StAR) facilitates its transfer to the inner membrane of the mitochondrion, a major control point in steroid production. There, the cholesterol side-chain-cleavage enzyme CYP11A1 converts 27-carbon cholesterol into 21-carbon pregnenolone. Subsequent reactions are divided between mitochondria and the smooth endoplasmic reticulum, requiring steroid intermediates to move between cellular compartments. CYP17A1 and CYP21A2 are endoplasmic-reticulum enzymes, whereas CYP11B1 and CYP11B2 catalyze the final mitochondrial reactions leading to cortisol and aldosterone, respectively. (ncbi.nlm.nih.gov)

In the cortisol pathway, the 17α-hydroxylase activity of CYP17A1 converts pregnenolone into 17α-hydroxypregnenolone. The enzyme 3β-hydroxysteroid dehydrogenase type 2, encoded by HSD3B2, then produces 17α-hydroxyprogesterone. CYP21A2, or 21-hydroxylase, converts this intermediate into 11-deoxycortisol; mitochondrial CYP11B1, or 11β-hydroxylase, completes the pathway by forming cortisol. Aldosterone synthesis instead proceeds through progesterone and 11-deoxycorticosterone, with CYP21A2 again supplying the 21-hydroxylation step. CYP11B2, also called aldosterone synthase, then performs successive 11β-hydroxylation, 18-hydroxylation, and 18-oxidation reactions, producing corticosterone, 18-hydroxycorticosterone, and finally aldosterone. The glomerulosa’s expression of CYP11B2 and lack of substantial CYP17A1 activity direct synthesis toward aldosterone rather than cortisol. (ncbi.nlm.nih.gov)

Cortisol secretion is controlled primarily by the hypothalamic–pituitary–adrenal axis. Corticotropin-releasing hormone (CRH), released by the hypothalamus, stimulates anterior-pituitary corticotrophs to secrete adrenocorticotropic hormone (ACTH). ACTH acts on the adrenal cortex to increase cortisol synthesis and secretion. Circulating cortisol supplies negative feedback at both hypothalamic and pituitary levels, restraining further CRH and ACTH release. This creates a regulatory loop in which adrenal output limits the signals driving its own production. (niddk.nih.gov)

The axis does not maintain a constant secretion rate. ACTH and cortisol exhibit pulsatile secretion superimposed on a circadian rhythm. Under typical sleep–wake conditions, ACTH concentrations peak approximately between 06:00 and 09:00, decline during the day, and reach a trough between approximately 23:00 and 02:00. Cortisol follows a corresponding daily pattern, with higher concentrations in the morning and lower concentrations at night. Physical or psychological stress can increase axis activity despite the restraining effect of cortisol feedback. (ncbi.nlm.nih.gov)

Aldosterone regulation depends principally on the renin–angiotensin system and circulating potassium, rather than on the CRH–ACTH feedback loop. Renin released by the kidney cleaves angiotensinogen to angiotensin I, which angiotensin-converting enzyme converts into angiotensin II. Angiotensin II stimulates zona glomerulosa steroidogenesis. Increased plasma potassium also stimulates aldosterone production, independently providing a signal linked to electrolyte balance. Both signals promote the machinery for aldosterone synthesis, including CYP11B2 expression. ACTH can influence aldosterone secretion, but its regulatory contribution is smaller than those of angiotensin II and potassium. (ncbi.nlm.nih.gov)

Physiological functions and disorders of endogenous production

Cortisol supports fuel availability during fasting, illness, injury, and other physiological stresses. It promotes hepatic gluconeogenesis, helping maintain circulating glucose when dietary carbohydrate is unavailable, and counteracts insulin-mediated glucose utilization in peripheral tissues. Its effects on protein turnover and fat breakdown mobilize amino acids, glycerol, and fatty acids: amino acids and glycerol can supply glucose synthesis, while fatty acids provide an alternative energy source. These effects are coordinated rather than independent; a 1989 human experimental study demonstrated that cortisol contributes to recovery from hypoglycemia by increasing glucose production, decreasing glucose utilization, and accelerating lipolysis. Sustained cortisol elevation, however, can convert this adaptive mobilization of resources into muscle wasting and disturbed glucose regulation. Cortisol also supports blood pressure partly by maintaining vascular responsiveness to catecholamines such as noradrenaline, and constrains excessive inflammation during the stress response. (pubmed.ncbi.nlm.nih.gov)

Aldosterone chiefly regulates sodium and potassium handling by the kidneys. In the distal nephron, it increases the capacity of epithelial cells to reabsorb sodium and secrete potassium into urine. Sodium retention supports extracellular fluid volume because retained sodium is accompanied by water, thereby contributing to blood-volume and blood-pressure maintenance. Potassium excretion helps preserve the electrolyte conditions required for normal nerve, muscle, and cardiac function. In a 2024 experimental study, elevated aldosterone increased expression of an epithelial sodium-channel subunit, illustrating its effects on renal sodium-transport machinery. Deficient aldosterone can consequently produce salt loss, volume depletion, low blood pressure, and hyperkalemia; these disturbances are particularly important when mineralocorticoid deficiency accompanies cortisol deficiency. (pubmed.ncbi.nlm.nih.gov)

Adrenal insufficiency is classified according to the site of the defect. Primary insufficiency results from adrenal disease and may impair both cortisol and aldosterone production. Acquired primary insufficiency is commonly called Addison’s disease; autoimmune destruction accounts for approximately 80–90% of cases in developed countries, while other causes include tuberculosis, hemorrhage, and adrenal removal. Secondary insufficiency results from inadequate pituitary secretion of adrenocorticotropic hormone (ACTH), whereas tertiary insufficiency results from inadequate corticotropin-releasing hormone secretion by the hypothalamus. In these central forms, reduced stimulation chiefly compromises cortisol production; aldosterone is generally preserved because its principal regulation is separate from ACTH. Fatigue, weakness, weight loss, and hypotension can occur across these categories, but marked potassium retention is more characteristic of accompanying aldosterone deficiency. Skin hyperpigmentation is a distinguishing feature of many cases of Addison’s disease. (niddk.nih.gov)

Endogenous Cushing’s syndrome results from prolonged excessive cortisol production. ACTH-secreting pituitary adenomas overstimulate the adrenal cortex; this specific form is called Cushing’s disease. ACTH can also originate from tumors outside the pituitary, while cortisol-secreting adrenal tumors produce excess independently of pituitary stimulation. Correspondingly, ACTH is usually suppressed in autonomous adrenal cortisol excess, but remains inappropriately normal or elevated in ACTH-dependent disease. Characteristic manifestations include central weight gain, thin limbs, proximal muscle weakness, easy bruising, broad purple striae, hypertension, and impaired glucose regulation or diabetes mellitus. In children, weight gain accompanied by slowing linear growth is an important pattern. These abnormalities reflect sustained exposure rather than the brief cortisol increases associated with ordinary physiological stress. (niddk.nih.gov)

Congenital adrenal hyperplasia comprises inherited defects in adrenal steroid synthesis. Approximately 95% of cases involve 21-hydroxylase deficiency, caused by pathogenic variants in CYP21A2 and inherited in an autosomal recessive pattern. The enzyme defect reduces cortisol synthesis and, in salt-wasting forms, aldosterone synthesis; accumulated precursors are diverted toward androgen production. Severe disease can therefore combine cortisol deficiency, potentially life-threatening neonatal salt loss, and androgen excess affecting genital development or causing early androgenic changes. Residual enzyme activity produces a spectrum ranging from classic salt-wasting disease to milder nonclassic presentations. Classic 21-hydroxylase deficiency occurs in approximately 1 in 15,000 newborns, although frequency varies among populations. Other enzyme defects produce different hormonal patterns: 11β-hydroxylase deficiency, for example, causes deficient cortisol and excess androgens without the characteristic aldosterone deficiency of salt-wasting 21-hydroxylase disease. (medlineplus.gov)

Receptors and mechanisms of action

Glucocorticoids bind to the intracellular glucocorticoid receptor (GR), a ligand-activated transcription factor. Ligand binding promotes movement of the receptor into the nucleus, where it regulates gene expression through interactions with DNA and other regulatory proteins. At glucocorticoid response elements, receptor binding can increase or decrease transcription; these elements need not lie immediately beside a gene’s promoter. A 2007 study of human A549 lung epithelial cells identified 73 GR-binding regions adjacent to 61 genes, with most identified response elements situated more than 10 kilobases from their associated transcription start sites. Receptor action therefore involves dispersed regulatory sequences rather than a uniform switch at each promoter. (pubmed.ncbi.nlm.nih.gov)

The transcriptional response depends on cellular context, including the accessibility of DNA within chromatin and the regulatory proteins already present. A 2018 study followed dexamethasone responses in A549 cells over 12 hours, measuring receptor occupancy, chromatin accessibility, histone modifications, and RNA production; it demonstrated that GR recruitment and enhancer activity involve coordinated changes across these features. Glucocorticoids also interfere with inflammatory transcriptional regulators. In experiments published in 2004, Helen Garside and colleagues demonstrated interactions between GR and the p65 component of NF-κB, with the bound ligand influencing this interaction. Such findings distinguish receptor entry into the nucleus from the subsequent molecular interactions that determine its effects on transcription. (pmc.ncbi.nlm.nih.gov)

Anti-inflammatory activity extends across multiple components of the immune system. Corticosteroids alter responses involving lymphocytes, macrophages, mast cells, eosinophils, and neutrophils, as well as mediators including cytokines, histamine, and eicosanoids, including leukotrienes. Their action cannot be reduced to inhibition of one inflammatory enzyme. One experimentally studied component is annexin A1, formerly called lipocortin-1: a 1994 investigation found that glucocorticoid treatment increased its expression in alveolar macrophages from patients with inflammatory lung disease, but not in blood-derived lympho-monocytes. This difference illustrates how cell differentiation influences glucocorticoid responsiveness. These mechanisms contribute to suppression of inflammation, although the precise combination responsible for corticosteroid efficacy in asthma is not fully established. (dailymed.nlm.nih.gov)

Mineralocorticoids act through the intracellular mineralocorticoid receptor (MR) in distal nephron tissues of the kidney. Receptor-mediated transcription increases proteins that support sodium transport, including serum- and glucocorticoid-regulated kinase 1 (SGK1). SGK1 inhibits NEDD4-2-mediated removal of epithelial sodium channels (ENaC), thereby increasing their availability at the tubular cell surface. In aldosterone-responsive cells, the enzyme 11β-hydroxysteroid dehydrogenase type 2 converts cortisol to cortisone, limiting inappropriate MR activation by cortisol. Increased sodium reabsorption is coupled to renal potassium secretion; fludrocortisone’s documented pharmacological effects include sodium retention and increased urinary potassium and hydrogen-ion excretion. Thus, mineralocorticoid action links regulation of transport proteins to changes in electrolyte balance. (pmc.ncbi.nlm.nih.gov)

Receptor affinity and experimental potency are distinct from demonstrated clinical effectiveness. Budesonide’s prescribing information reports approximately 200-fold greater GR affinity than cortisol and approximately 1,000-fold greater topical anti-inflammatory potency in a rat croton-oil ear-edema assay. In rat thymus-involution assays, its relative systemic potency was approximately 40-fold after subcutaneous administration and 25-fold after oral administration. These measurements describe different experimental endpoints and exposure conditions; the labeling explicitly identifies their clinical significance as unknown. They do not establish corresponding multipliers for symptom improvement or dose equivalence in humans. Clinical effects must instead be assessed in studies of the relevant disease, formulation, and administration route. (dailymed.nlm.nih.gov)

Pharmaceutical preparations and comparative pharmacology

Major systemic glucocorticoid preparations include hydrocortisone, cortisone acetate, prednisone, prednisolone, methylprednisolone, dexamethasone, and betamethasone. Their comparative pharmacology involves three distinct properties: glucocorticoid potency, mineralocorticoid activity, and duration of biological action. Hydrocortisone and cortisone acetate are short-acting agents; prednisone, prednisolone, and methylprednisolone are intermediate-acting; dexamethasone and betamethasone are long-acting. The 2024 joint European Society of Endocrinology–Endocrine Society guideline lists approximate biological half-lives of 8–12, 12–36, and 36–72 hours, respectively. These durations are not plasma elimination half-lives: hydrocortisone, for example, has a listed plasma half-life of approximately 90–120 minutes, substantially shorter than its biological effect. (pmc.ncbi.nlm.nih.gov)

Anti-inflammatory potency describes the relative amount of drug required to produce a comparable glucocorticoid effect, rather than the maximum therapeutic benefit attainable. With hydrocortisone assigned a relative potency of 1, the same guideline assigns approximately 0.8 to cortisone acetate, 4 to prednisone and prednisolone, 5 to methylprednisolone, 30–60 to dexamethasone, and 25–40 to betamethasone. These estimates do not include mineralocorticoid effects. Hydrocortisone and cortisone have appreciable salt-retaining activity; product information notes that such effects are generally less likely with synthetic derivatives except at large doses. Consequently, greater anti-inflammatory potency does not imply proportionately greater sodium retention or an otherwise identical physiological profile. (pmc.ncbi.nlm.nih.gov)

Prednisone illustrates the distinction between an administered precursor and its active metabolite. Its 11-keto group is reduced to the 11β-hydroxyl group of prednisolone by the enzyme 11β-hydroxysteroid dehydrogenase type 1, including in the liver. Prednisolone is the active glucocorticoid generated by this reaction and is also available as a medicine in its own right. Thus, administering prednisone requires metabolic activation, whereas administering prednisolone supplies the active compound directly. Cortisone similarly undergoes conversion to active cortisol. Product information for delayed-release prednisone explicitly identifies prednisolone as its active metabolite; release characteristics and metabolic activation are separate features of the preparation. (pmc.ncbi.nlm.nih.gov)

Equivalent-dose tables express approximate comparisons of systemic glucocorticoid effects, not complete interchangeability between preparations. The SOLU-MEDROL prescribing information restricts its listed dose relationships to oral or intravenous administration and states that relative properties can change substantially after intramuscular or intra-articular injection. The 2024 joint guideline likewise describes equivalence estimates as historically accepted approximations affected by administration route, individual metabolism, and susceptibility. Such tables do not equate mineralocorticoid activity, duration of effect, or formulation-dependent exposure. Their purpose is pharmacological comparison; a numerical equivalence alone does not establish an appropriate replacement regimen or predict an identical clinical response. (dailymed.nlm.nih.gov)

Fludrocortisone, supplied as fludrocortisone acetate, occupies a different pharmaceutical role. Its product information describes both very potent mineralocorticoid properties and substantial glucocorticoid activity, but identifies its use as being for mineralocorticoid effects. Small oral amounts produce marked sodium retention and increased urinary potassium excretion. In Addison’s disease, the labeled replacement approach combines fludrocortisone acetate with a glucocorticoid such as hydrocortisone or cortisone, separating replacement of salt-regulating activity from replacement of glucocorticoid activity. Its dual pharmacological profile therefore does not make it simply another anti-inflammatory glucocorticoid preparation. (dailymed.nlm.nih.gov)

Administration routes, formulations, and disposition

Oral corticosteroids, exemplified by prednisone tablets, provide systemic delivery after gastrointestinal absorption. Parenteral preparations can likewise provide systemic treatment: the water-soluble sodium succinate ester of hydrocortisone is formulated for intravenous or intramuscular administration and permits rapid attainment of high blood concentrations by intravenous injection. In contrast, inhaled preparations target the respiratory tract, cutaneous preparations target the skin, and intra-articular or intralesional injections place drug directly within a joint or lesion. The intended site of action does not determine the limits of exposure: locally administered corticosteroids can enter the circulation. Formulation also restricts the permissible route; triamcinolone acetonide suspensions intended for joint or lesion injection are not interchangeable with intravenous solutions. (dailymed.nlm.nih.gov)

Inhaled budesonide illustrates the distinction between local delivery and systemic absorption. Drug deposited in the lungs acts locally but is also absorbed into the circulation; swallowed drug contributes through gastrointestinal absorption. Extensive hepatic first-pass metabolism degrades approximately 85–95% of orally absorbed budesonide before it reaches the systemic circulation. Delivery devices influence the amount reaching the lungs: laboratory testing of the Pulmicort Flexhaler dry-powder inhaler found that its fine-particle dose at an airflow of 30 litres/minute was approximately 40–50% of that produced at 60 litres/minute. These are device-performance measurements, not direct measurements of clinical efficacy. For a different formulation—budesonide suspension administered by jet nebulizer—total absolute systemic bioavailability, combining pulmonary and oral contributions, was approximately 6% of the labelled dose in children aged four to six years with asthma. (dailymed.nlm.nih.gov)

The subsequent disposition of budesonide is documented separately from its delivery. Approximately 85–90% is bound to plasma proteins, with little or no binding to corticosteroid-binding globulin. Hepatic CYP3A4-mediated metabolism produces principally 16α-hydroxyprednisolone and 6β-hydroxybudesonide; each has less than 1% of the corticosteroid activity of the parent compound. Elimination occurs predominantly through hepatic metabolism, with metabolites excreted in urine and faeces. In adults, approximately 60% of an intravenously administered radiolabelled dose was recovered in urine, without detectable unchanged budesonide. Its terminal plasma half-life after nebulization was approximately 2.3 hours in the studied four- to six-year-old children. (dailymed.nlm.nih.gov)

Oral formulation can alter absorption timing without equivalently changing elimination. In a study of 27 healthy male subjects, delayed-release prednisone produced a median time to peak plasma concentration of 6.0–6.5 hours, compared with 2.0 hours for immediate-release prednisone. Under the studied fed conditions, peak concentrations and overall exposure were comparable, although fasting reduced absorption of the delayed-release product. Prednisone is converted to active prednisolone, which undergoes further metabolism mainly in the liver and is excreted in urine as sulfate and glucuronide conjugates. The terminal half-lives of prednisone and prednisolone following delayed-release administration were approximately two to three hours. These observations describe particular preparations and study conditions rather than a uniform pharmacokinetic profile for the entire corticosteroid class. (dailymed.nlm.nih.gov)

For cutaneous preparations, absorption depends on the vehicle and the integrity of the epidermal barrier; skin inflammation can increase penetration, and absorption can occur even through intact skin. Intralesional triamcinolone labelling likewise notes that greater total injected volume makes more corticosteroid available for systemic absorption. The 2024 joint European Society of Endocrinology–Endocrine Society guideline identifies high-dose inhaled or topical exposure, use of these preparations for more than one year, simultaneous use of multiple glucocorticoid formulations, and intra-articular injections within the preceding two months as contexts in which glucocorticoid-induced adrenal insufficiency may occur. Thus, local formulations reduce or redirect exposure rather than necessarily eliminating systemic endocrine effects. (dailymed.nlm.nih.gov)

Established therapeutic applications

In adrenal insufficiency, glucocorticoids replace deficient cortisol rather than primarily suppressing inflammation. Hydrocortisone, chemically identical to cortisol, is a standard replacement preparation; cortisone acetate and prednisolone are alternatives in particular circumstances. The Endocrine Society’s 2016 guideline describes divided hydrocortisone administration with the largest portion in the morning, reflecting the normal daily pattern of cortisol secretion. Replacement also accounts for increased physiological requirements during illness or surgery. When primary adrenal disease additionally causes aldosterone deficiency, fludrocortisone provides a separate mineralocorticoid component, supporting sodium retention and salt–water balance. Glucocorticoid replacement and mineralocorticoid replacement therefore address distinct deficiencies; the latter is determined by aldosterone deficiency, not simply by the presence of low cortisol. (endocrine.org)

Anti-inflammatory applications include rheumatoid arthritis and systemic lupus erythematosus. The United States prescribing information for prednisone identifies rheumatoid arthritis as an indication for adjunctive treatment, particularly during acute episodes or exacerbations, and lupus as an indication during exacerbations or in selected maintenance circumstances. Here, the therapeutic objective differs from hormone replacement: glucocorticoids suppress inflammatory and immune activity to control manifestations of disease. A reduction in joint symptoms or other inflammatory manifestations does not establish that the underlying autoimmune process has been eliminated. Their role is consequently disease- and circumstance-specific rather than a general cure for autoimmune disease. (dailymed.nlm.nih.gov)

In inflammatory bowel disease, corticosteroids are used principally to control active inflammation and induce remission. For ulcerative colitis, documented applications include moderate-to-severe disease and milder disease that has not responded to aminosalicylates; corticosteroids are not ordinarily used for long-term maintenance of remission. This distinction separates treatment of an inflammatory episode from sustained disease control. In dermatology, local treatment targets inflammatory and itchy manifestations of steroid-responsive disorders. For example, hydrocortisone valerate cream, 0.2%, is labeled for such manifestations in adults, whereas prednisone labeling includes selected severe inflammatory skin diseases, including severe psoriasis and seborrheic dermatitis. These indications concern responsive manifestations and do not imply that every skin eruption benefits from corticosteroids. (niddk.nih.gov)

For asthma, inhaled glucocorticoids provide anti-inflammatory maintenance treatment rather than immediate relaxation of airway smooth muscle. Budesonide inhalation suspension, for example, is labeled in the United States for maintenance and prophylactic treatment in children aged 12 months to 8 years, but not for relief of acute bronchospasm. Its supporting trials included 946 children in this age range across three controlled studies, with significant improvements in daytime and nighttime symptom scores at several studied doses. Systemic corticosteroids have a different role during selected exacerbations: the 2026 Global Initiative for Asthma guide describes short-term use in severe acute exacerbations to reduce early recurrence. When an inhaled corticosteroid is supplied together with a rapid-acting bronchodilator, the combination’s immediate bronchodilation must be distinguished from the corticosteroid’s anti-inflammatory contribution. (dailymed.nlm.nih.gov)

Hematological indications include adult immune thrombocytopenia and acquired autoimmune hemolytic anemia, both listed in prednisone prescribing information. Oncological applications are likewise specific to particular diseases and treatment protocols. Prednisone or dexamethasone forms part of remission-induction treatment for childhood acute lymphoblastic leukemia, while prednisone is a component of R-CHOP, a combination used for diffuse large B-cell lymphoma. R-CHOP combines prednisone with rituximab, cyclophosphamide, doxorubicin, and vincristine; the steroid is therefore incorporated into a defined multidrug regimen, not presented as a substitute for the other agents. These established uses in lymphoid malignancies do not demonstrate general anticancer activity across unrelated cancers. (dailymed.nlm.nih.gov)

Adverse effects and determinants of risk

Adverse-effect risk depends on dose, treatment duration, glucocorticoid potency and duration of action, administration route, and individual susceptibility. Milligram doses of different preparations are therefore not interchangeable measures of risk. Local administration does not eliminate systemic exposure, particularly with high-dose or prolonged inhaled or topical treatment or simultaneous use of several formulations. Pre-existing diabetes, reduced bone mass, and impaired drug clearance can increase vulnerability to particular complications. The 2024 joint European Society of Endocrinology–Endocrine Society guideline identifies increased risks of severe infection, hypertension, diabetes mellitus, osteoporosis, and fractures even at prednisone doses of 2.5–7.5 mg daily; prolonged low-dose treatment is not equivalent to absence of risk. Adrenal suppression and withdrawal constitute a separate, related group of complications. (endocrine.org)

Systemic glucocorticoids can cause hyperglycemia, reveal previously unrecognized diabetes, or worsen established diabetes. Prolonged exposure may also produce weight gain and altered body-fat distribution, including a rounded face, increased fat around the neck and trunk, and relatively thin limbs. These changes can coexist with muscle wasting and weakness rather than representing uniform tissue growth. Bone toxicity involves inhibition of bone-forming osteoblasts, reduced intestinal calcium absorption, increased calcium excretion, and loss of the bone’s protein matrix through increased protein breakdown. Consequences include osteoporosis, vertebral compression fractures, and fractures of other bones. Muscle protein catabolism contributes to loss of muscle mass and steroid myopathy; osteonecrosis of the femoral or humeral head is another documented musculoskeletal complication. (dailymed.nlm.nih.gov)

Suppression of the immune system increases susceptibility to infection and can worsen existing infections while masking inflammatory signs. A 2020 observational cohort study by Michael D. George and colleagues examined adults with rheumatoid arthritis receiving stable disease-modifying treatment. In its Medicare population, the estimated one-year incidence of infection requiring hospitalization was 8.6% without glucocorticoids, compared with 11.0% at prednisone-equivalent doses of 5 mg daily or less, 14.4% above 5–10 mg, and 17.7% above 10 mg. These estimates describe that study population, not universal individual probabilities; residual confounding remained possible. Skin thinning, easy bruising, stretch marks, and impaired wound healing are also documented consequences of systemic exposure. (pmc.ncbi.nlm.nih.gov)

Neuropsychiatric effects range from insomnia, euphoria, irritability, and mood swings to severe depression and psychotic manifestations; existing psychiatric disturbances may be aggravated. Ocular complications include cataracts and increased intraocular pressure, which can lead to glaucoma, and are reported with prolonged systemic and inhaled exposure. Childhood growth can slow even when laboratory tests do not demonstrate adrenal suppression. The budesonide inhalation-suspension label summarizes controlled inhaled-corticosteroid studies reporting an average reduction in growth velocity of approximately 1 cm per year, with a range of 0.3–1.8 cm per year. This measures growth during treatment rather than an equivalent, established reduction in final adult height. (dailymed.nlm.nih.gov)

Route-related local adverse effects should be distinguished from systemic glucocorticoid toxicity and mineralocorticoid effects. Inhaled preparations can produce oral or pharyngeal candidiasis; budesonide labeling documents localized Candida albicans infections, although rates in its inhalation-suspension trials were similar to placebo. By contrast, mineralocorticoid activity increases renal sodium retention and potassium loss. Fludrocortisone’s adverse effects consequently include edema, hypertension, potassium depletion, and hypokalemic alkalosis; fluid retention can aggravate heart failure in susceptible patients. The relative importance of these effects varies between preparations because glucocorticoid potency and salt-retaining activity are distinct pharmacological properties. (dailymed.nlm.nih.gov)

Adrenal suppression, withdrawal, and recovery

Exogenous glucocorticoids reproduce cortisol’s negative feedback on the hypothalamus and anterior pituitary, inhibiting corticotropin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH). Reduced ACTH stimulation lowers endogenous cortisol production; prolonged suppression can cause adrenal cortical atrophy. Consequently, substantial glucocorticoid activity supplied by medication can coexist with a reduced capacity to produce cortisol independently. Aldosterone secretion is usually preserved because its principal regulators are the renin–angiotensin system and potassium rather than ACTH. This distinguishes drug-induced suppression from primary adrenal failure involving both cortisol and aldosterone deficiency. (academic.oup.com)

Four conditions must be distinguished during withdrawal. Glucocorticoid-induced adrenal insufficiency means endogenous cortisol production cannot adequately meet physiological requirements, particularly after medication falls below replacement requirements or during illness. Glucocorticoid withdrawal syndrome comprises malaise, fatigue, nausea, muscle and joint pain, sleep disturbance, and mood changes accompanying reduced exposure; it can occur while the administered dose still exceeds normal physiological requirements. Recurrence of the treated disease produces disease-specific manifestations, such as renewed inflammatory joint symptoms in rheumatoid arthritis. Exogenous Cushing’s syndrome reflects excessive glucocorticoid exposure, with features such as central fat accumulation, facial rounding, bruising, and proximal muscle weakness, despite suppressed endogenous cortisol. Fatigue and weakness overlap across these conditions, and withdrawal syndrome can coexist with adrenal insufficiency. Near physiological doses, symptoms alone do not reliably distinguish them. (pmc.ncbi.nlm.nih.gov)

The degree and persistence of suppression depend on overall exposure: dose, duration, potency, administration route, simultaneous preparations, and individual susceptibility. The 2024 joint European Society of Endocrinology–Endocrine Society guideline identifies oral exposure exceeding both approximately three to four weeks and a physiological daily equivalent—about 4–6 mg of prednisone—as a clinically important risk range, not a precise boundary between safety and suppression. Recovery after withdrawal is highly variable. Studies reviewed in the guideline reported biochemical recovery in 58.8% of participants in one cohort after a median of 16 months, and 60.6% in another with a median recovery time of 24 months. These estimates came from heterogeneous, limited studies; biochemical impairment did not necessarily establish symptomatic disease. Suppression can persist for two to four years in some patients. (endocrine.org)

Clinician-directed withdrawal separates control of the original disease from restoration of endogenous cortisol secretion. For long-term treatment, dose reduction is considered when the underlying disease is controlled and glucocorticoids are no longer required. Reductions can generally proceed more rapidly while exposure remains supraphysiological, but become more cautious near physiological replacement levels, where the recovering adrenal axis must increasingly provide cortisol. Clinical assessment addresses disease activity, withdrawal symptoms, and signs of deficiency rather than assuming every symptom represents the same process. Routine adrenal testing during continuing supraphysiological treatment is generally uninformative because suppression is expected and medication still supplies glucocorticoid activity. (endocrine.org)

Morning serum cortisol is the guideline’s initial blood test for assessing recovery once treatment has reached the physiological range. Results are interpreted as a continuum: values above approximately 300 nmol/L (10 μg/dL) support recovery, values below approximately 150 nmol/L (5 μg/dL) suggest persistent suppression, and intermediate values leave uncertainty. These are clinical interpretive guides, not universal assay-independent boundaries. Laboratory method, medication timing, sleep pattern, and altered cortisol-binding proteins affect interpretation. Repeat measurements may document recovery over time; ACTH stimulation testing can be considered for unresolved uncertainty but is not routinely required during withdrawal. (endocrine.org)

An adrenal crisis occurs when available glucocorticoid activity is insufficient for acute physiological stress. Infection, surgery, trauma, abrupt withdrawal, or gastrointestinal illness that impairs medication absorption can precipitate it. Severe hypotension, volume depletion, vomiting, abdominal symptoms, profound weakness, and impaired consciousness may progress to shock; hyponatremia or hypoglycemia can accompany the episode. Crisis may be the first overt manifestation of previously unrecognized suppression, including after non-oral treatment. It is a medical emergency managed with parenteral glucocorticoids and fluid resuscitation, without delaying treatment for confirmatory testing. (pmc.ncbi.nlm.nih.gov)

Drug interactions and special clinical contexts

Strong inhibitors of CYP3A4, an enzyme involved in corticosteroid metabolism, can increase systemic exposure to budesonide. Documented examples include ketoconazole, itraconazole, ritonavir, and clarithromycin. The quantitative evidence is formulation-specific: in a crossover study of six healthy subjects, ketoconazole increased the area under the plasma concentration–time curve of orally administered budesonide eightfold. A separate study of eight subjects found that concentrated grapefruit juice approximately doubled the bioavailability of budesonide delayed-release capsules through inhibition predominantly in the intestinal mucosa. These oral results do not establish an identical increase for inhaled preparations. The inhalation-suspension label nevertheless identifies strong CYP3A4 inhibitors as potentially increasing systemic exposure despite the intended pulmonary action. (dailymed.nlm.nih.gov)

Several interactions described in prednisone product information concern overlapping physiological effects rather than inhibition of drug metabolism. Potassium-depleting diuretics and amphotericin B can increase the risk of hypokalemia when combined with corticosteroids; concomitant digitalis glycosides add a risk of arrhythmias in this setting. Corticosteroid-induced increases in blood glucose can oppose antidiabetic treatment and increase insulin or oral hypoglycemic-drug requirements. The interaction with warfarin is not reliably unidirectional: prednisone labeling describes reduced anticoagulant response as usual but acknowledges conflicting reports. Aspirin and other nonsteroidal anti-inflammatory drugs increase gastrointestinal adverse-effect risk during corticosteroid treatment. Corticosteroids can also increase salicylate clearance, so withdrawal may raise salicylate concentrations and toxicity risk. (dailymed.nlm.nih.gov)

Suppression of the immune system affects both vaccination and the interpretation of possible infection. Prednisone labeling contraindicates live or live-attenuated vaccines at immunosuppressive doses; responses to inactivated vaccines may also be diminished. This restriction is distinguished from corticosteroid replacement therapy, which does not necessarily produce the same degree of immunosuppression. Corticosteroids may mask signs of infection, exacerbate existing infection, or permit latent infection to reactivate. Documented contexts include tuberculosis and hepatitis B reactivation, severe varicella or measles in nonimmune patients, and Strongyloides hyperinfection with disseminated larvae. Infection assessment therefore concerns prior exposure and latent infection as well as newly acquired illness. (dailymed.nlm.nih.gov)

Evidence in pregnancy differs by preparation and route. Prednisone labeling reports animal developmental toxicity and inadequate controlled studies in pregnant women, while substantial maternal exposure raises concern about neonatal adrenal suppression. In contrast, inhaled-budesonide labeling includes observational data from Swedish registries covering pregnancies in 1995–1997. Among 2,014 infants whose mothers reported inhaled budesonide during early pregnancy, recorded congenital malformations occurred in 3.8%, compared with 3.5% in the general population. These findings support the absence of an observed increase in that cohort, rather than proof of safety for every dose, formulation, or pregnancy outcome. The same label identifies poorly controlled maternal asthma as a separate contributor to adverse perinatal outcomes. (dailymed.nlm.nih.gov)

In children, decreased growth velocity has been observed with corticosteroids at low systemic doses and without laboratory evidence of hypothalamic–pituitary–adrenal suppression, making growth effects distinct from demonstrable adrenal suppression. In older adults, prednisone labeling notes that clinical studies included too few participants aged 65 years or older to establish whether responses differ from those of younger adults. It nevertheless identifies diabetes mellitus, fluid retention, and hypertension as important age-related clinical considerations, alongside the greater frequency of impaired organ function, coexisting disease, and concurrent medicines. These are documented risk considerations, not evidence that all older patients respond differently. (dailymed.nlm.nih.gov)

Discovery and development

In 1929, Frank A. Hartman and colleagues at the University of Buffalo, and William W. Swingle and John J. Pfiffner at Princeton University, prepared adrenal-cortex extracts that controlled symptoms of adrenal insufficiency in animals whose adrenal glands had been removed and in patients with Addison’s disease. These preparations established that extractable substances from the cortex could replace essential adrenal functions, but they were mixtures rather than chemically defined medicines. Cortisone was first separated as a distinct compound in 1935. Its isolation and structural investigation proceeded independently in Edward C. Kendall’s laboratory at the Mayo Clinic, Tadeus Reichstein’s group in Zurich, and the work of Oskar Wintersteiner and Pfiffner at Columbia University. Kendall’s designation “compound E” preceded the name cortisone. (nobelprize.org)

Turning an isolated hormone into a usable medicine required both chemical production and suitable formulation. Lewis H. Sarett, working at Merck in collaboration with Kendall, made the first few milligrams of cortisone acetate in late 1944; subsequent improvements in 1947–1948 increased the supply available for clinical investigation. Absorption also mattered: Kendall’s group found that a finely divided crystalline suspension could provide sustained delivery, whereas large crystals were absorbed too slowly. In summer 1948, Mayo physician Randall G. Sprague administered compound E to a patient with Addison’s disease and observed improvement. These experiments connected hormone isolation, industrial synthesis, and practical drug delivery before the rheumatoid-arthritis trial. (nobelprize.org)

Philip S. Hench supplied the clinical hypothesis behind testing cortisone in rheumatoid arthritis. He had investigated temporary remissions associated with pregnancy and jaundice and proposed an unidentified physiological substance capable of reversing manifestations of the disease. Once Merck supplied sufficient compound E, Hench and Kendall selected it for clinical testing. On September 21, 1948, Charles H. Slocumb, Hench’s colleague, began intramuscular administration to a woman with severe rheumatoid arthritis, using a crystalline suspension in saline. Hench’s Nobel lecture records a historical trial dose of 100 mg daily and marked improvement within three days. Howard F. Polley subsequently participated in extending the investigations to additional patients. Reichstein’s contribution was the independent chemical investigation of adrenal steroids, rather than participation in this Mayo clinical trial. (nobelprize.org)

The 1950 Nobel Prize in Physiology or Medicine was divided equally among Edward Calvin Kendall, Tadeus Reichstein, and Philip Showalter Hench. Its stated basis was “their discoveries relating to the hormones of the adrenal cortex, their structure and biological effects.” The award therefore recognized a body of chemical and biological research, not simply the identification of one anti-inflammatory medicine: Kendall and Reichstein helped distinguish and characterize adrenal-cortex compounds, while Hench’s clinical work demonstrated their effects in rheumatic disease. (nobelprize.org)

Later pharmaceutical development differentiated corticosteroids by chemical modification and intended site of action. Synthetic prednisone exemplifies preparations used principally for systemic anti-inflammatory effects, in contrast to the replacement role of naturally occurring cortisone and hydrocortisone. Fludrocortisone acetate, a fluorinated synthetic steroid, possesses both glucocorticoid and potent mineralocorticoid activity but is used for its mineralocorticoid effects. Budesonide illustrates a different approach: inhaled formulations deliver anti-inflammatory activity directly to the respiratory tract in asthma, while extensive first-pass hepatic degradation—85–95% of orally absorbed drug—and weakly active metabolites limit the contribution of swallowed drug to systemic exposure. This local-delivery strategy does not eliminate systemic corticosteroid effects. (dailymed.nlm.nih.gov)

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