Corticosteroids
Glucocorticoid receptor agonists; most potent anti-inflammatory class. Suppress NF-κB/AP-1 → ↓ cytokines, eosinophils, vascular permeability. ICS for asthma/COPD maintenance; systemic for acute asthma, ARDS, anaphylaxis. RECOVERY trial: dexamethasone 6 mg/d cut COVID-19 ventilator mortality 36%. Nobel Prize 1950.
Overview
Corticosteroids (glucocorticoids used clinically) are steroid hormones that bind and activate the glucocorticoid receptor (GR, NR3C1), producing the most potent anti-inflammatory effect of any drug class in clinical medicine. The class encompasses both endogenous cortisol (hydrocortisone) and a wide range of synthetic derivatives engineered for enhanced anti-inflammatory potency, altered pharmacokinetics, and reduced mineralocorticoid side effects.
The therapeutic era began in 1948 when Philip Hench administered compound E (cortisone) to a patient bedridden with severe rheumatoid arthritis — within two days she could walk; within weeks her debilitating disease was in remission. Hench, Kendall, and Reichstein shared the 1950 Nobel Prize in Physiology or Medicine for this discovery. Within a decade, the class had been adopted across pulmonology, critical care, rheumatology, allergy, dermatology, and oncology.
In respiratory medicine specifically, two therapeutic roles define the class: inhaled corticosteroids (ICS) — budesonide, fluticasone, beclomethasone — as the cornerstone of persistent asthma maintenance (GINA Steps 2–5), reducing exacerbation rates by 50–60% and hospitalizations by approximately 80%; and systemic corticosteroids (prednisolone, methylprednisolone, dexamethasone) for acute severe asthma, COPD exacerbations, ARDS, and COVID-19 critical illness. The 2021 RECOVERY trial, demonstrating a 36% reduction in 28-day mortality in mechanically ventilated COVID-19 patients treated with dexamethasone 6 mg/day, stands as one of the most important landmark trials of the 21st century for any respiratory indication.
Mechanism of Action
Genomic Pathway — GR-Mediated Transactivation and Transrepression
Corticosteroid (lipophilic steroid)
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| passive diffusion across cell membrane
v
Cytoplasmic GR-HSP90 complex
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| ligand binding --> HSP90 dissociation
v
GR-ligand complex
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+--- [NUCLEUS: GR homodimer] -----------------------------------------
| | |
| | binds GRE (glucocorticoid response elements) |
| v |
| TRANSACTIVATION |
| ^ IkBa (NF-kB inhibitor) |
| ^ GILZ (anti-inflammatory mediator) |
| ^ Annexin-1 (phospholipase A2 inhibitor) |
| ^ MKP-1 (MAPK phosphatase -- inactivates ERK/JNK/p38) |
| |
+--- [NUCLEUS: GR monomer tethers NF-kB p65 / AP-1 (c-Fos/c-Jun)] -+
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| TRANSREPRESSION -- blocks binding to inflammatory promoters
v
v TNF-a v IL-1b v IL-6 v IL-8
v COX-2 v iNOS v VCAM-1 v ICAM-1
The dual mechanism — transactivation of anti-inflammatory genes and transrepression of pro-inflammatory transcription factors — explains why corticosteroids are so broadly and potently effective. The transrepression arm (suppression of NF-κB and AP-1) is responsible for most therapeutic benefit; transactivation of metabolic genes (gluconeogenesis, lipolysis, protein catabolism) accounts for many of the adverse effects seen with prolonged systemic use.
- GR binding: Corticosteroid diffuses through the lipophilic cell membrane and binds the cytoplasmic glucocorticoid receptor (GR), displacing HSP90 chaperones that hold GR in an inactive conformation
- Nuclear translocation: GR–ligand complex translocates into the nucleus; GR homodimers bind glucocorticoid response elements (GREs) in target gene promoter regions
- Transactivation of anti-inflammatory genes: Drives transcription of IκBα (sequesters NF-κB in cytoplasm), GILZ, Annexin-1 (inhibits phospholipase A2), and MKP-1 (dephosphorylates and inactivates MAPK signaling)
- Transrepression of NF-κB and AP-1: GR monomer physically tethers to NF-κB p65 and AP-1 (c-Fos/c-Jun), preventing their binding to promoters of TNF-α, IL-1β, IL-6, IL-8, COX-2, iNOS, and endothelial adhesion molecules
- Non-genomic effects (minutes timescale): Membrane-associated GR signaling; cAMP elevation; relevant for rapid bronchodilator augmentation and acute anti-edema effects in anaphylaxis, before genomic effects develop
Net Pharmacological Effects on the Airway and Immune Response
Airway eosinophil suppression
Reduced eosinophil survival (promotes apoptosis) and inhibition of eotaxin-driven recruitment to the airway mucosa; primary mechanism of exacerbation prevention in eosinophilic asthma
Cytokine storm attenuation
Suppression of IL-6, TNF-α, IL-1β, IL-8 via NF-κB transrepression; mechanism underlying the mortality benefit in COVID-19 hyperinflammation demonstrated by RECOVERY trial
Vascular permeability reduction
Upregulation of Annexin-1 inhibits phospholipase A2, reducing prostaglandins and leukotrienes; decreases mucosal edema, airway secretions, and anaphylactic vascular leak
Beta-2 receptor upregulation
Corticosteroids increase airway smooth muscle β₂-adrenergic receptor expression and prevent agonist-induced downregulation — explains the pharmacological synergy with SABA and LABA combination inhalers
Indications
Per GINA 2023 (asthma), GOLD 2023 (COPD), and international critical care guidelines:
| Patient Group | Recommendation | Dosing |
|---|---|---|
| Persistent asthma — maintenance (GINA Steps 2–5) | Inhaled corticosteroids (ICS) — first-line controller therapy | Low/medium/high ICS doses by agent: budesonide 200–1600 μg/day, fluticasone propionate 100–1000 μg/day, beclomethasone 200–2000 μg/day; step-up with LABA at Steps 3–4 |
| Acute severe asthma | Systemic corticosteroids — first-line alongside bronchodilators | Oral prednisolone 40–50 mg/day × 5–7 days; IV hydrocortisone 100 mg every 6h if unable to swallow; IV methylprednisolone 40–125 mg; reduces relapse rate after ED discharge by ~50% |
| COPD exacerbation (GOLD 2023) | Systemic prednisolone — recommended for moderate–severe exacerbations | Oral prednisolone 30–40 mg/day × 5 days; non-inferior to 14-day course; fewer treatment failures, shorter hospital stay vs. placebo |
| COVID-19 — mechanically ventilated or supplemental O₂ (RECOVERY) | Dexamethasone — standard of care; WHO-recommended | Dexamethasone 6 mg/day × 10 days (oral or IV); 36% ↓ mortality in ventilated patients; 18% ↓ in oxygen-only patients; no benefit (possible harm) in patients not requiring supplemental oxygen |
| ARDS | Dexamethasone or methylprednisolone — evidence supports use in early moderate–severe ARDS | DEXA-ARDS protocol: dexamethasone 20 mg/day × 5 days then 10 mg/day × 5 days; improved ventilator-free days and reduced 60-day mortality |
| Anaphylaxis / severe allergic reaction | Adjunct to adrenaline — used to prevent biphasic anaphylaxis | IV hydrocortisone 200 mg or oral prednisolone 50 mg; onset delayed relative to adrenaline; onset of genomic effects 2–4 hours; routine use debated in current guidelines |
Key Agents
| Agent | Route | Potency vs. Cortisol | Notes |
|---|---|---|---|
| Budesonide | Inhaled (DPI / MDI / nebulizer) | High ICS potency; ~11% oral bioavailability (low systemic) | Most extensively studied ICS; on WHO Essential Medicines List; nebulized form used in children under 5 and croup; reference ICS in most GINA trials |
| Fluticasone propionate / furoate | Inhaled (MDI / DPI) | High ICS potency; <1% oral bioavailability | Fluticasone furoate (Ellipta device) once-daily; fluticasone propionate in Seretide (+ salmeterol), Relvar (+ vilanterol), Breo (+ vilanterol); widest ICS/LABA range |
| Beclomethasone dipropionate | Inhaled (MDI) | Moderate; activated in lung to active BMP metabolite | Longest clinical track record; extra-fine particle formulation (QVAR) achieves small-airway deposition; also in COPD triple therapy combinations |
| Ciclesonide | Inhaled (MDI) | Prodrug; activated by airway esterases; low oropharyngeal deposition | Lowest oral candidiasis and dysphonia risk of ICS class; once-daily dosing; minimal systemic effects; useful in patients intolerant of other ICS |
| Prednisolone / prednisone | Oral | 4× cortisol; moderate mineralocorticoid activity | Standard systemic agent for COPD exacerbations, acute asthma, most inflammatory indications; prednisone is a prodrug converted hepatically to active prednisolone; widely available generically |
| Dexamethasone | Oral / IV | 25× cortisol; negligible mineralocorticoid activity | RECOVERY trial agent (COVID-19); long half-life 36–54h; preferred in CNS (cerebral edema) and critical-care settings; anti-emesis in oncology; can cause significant HPA suppression due to long half-life |
| Methylprednisolone | IV / oral | 5× cortisol; minimal mineralocorticoid activity | IV agent for severe asthma, status asthmaticus, ARDS (DEXA-ARDS protocol); pulse dosing (500–1000 mg IV) in rheumatological emergencies and transplant rejection |
| Hydrocortisone | IV | 1× (reference cortisol equivalent); significant mineralocorticoid activity | Anaphylaxis adjunct; low-dose (200 mg/day infusion) septic shock with refractory vasopressor dependence; adrenal insufficiency replacement; fastest onset systemic agent |
Evidence Base
| Trial / Guideline | Drug | Population | Key Result |
|---|---|---|---|
| RECOVERY (2021) | Dexamethasone 6 mg/d × 10d | 6,425 hospitalized COVID-19 patients requiring oxygen or ventilation; UK multicentre open-label RCT | RR 0.83 overall; RR 0.64 (95% CI 0.51–0.81) in ventilated patients — 36% ↓ 28-day mortality. No benefit if no supplemental O₂ required (RR 1.22; possible harm). |
| DEXA-ARDS (2020) | Dexamethasone 20 mg → 10 mg × 10d | 277 patients moderate–severe ARDS (PaO₂/FiO₂ <200); Spanish multicentre RCT | +4.8 ventilator-free days (p=0.04); 21% vs. 36% 60-day mortality (p=0.02). First dedicated ARDS RCT showing mortality benefit with corticosteroids. |
| GINA 2023 (meta-evidence) | ICS (budesonide, fluticasone, beclomethasone) | Persistent asthma — GINA Steps 2–5 guideline population; multiple RCTs | ICS reduces exacerbation rate 50–60%, hospitalizations ~80%, near-fatal asthma events; systematic review basis; no alternative controller therapy matches this benefit profile. |
| GOLD 2023 (meta-evidence) | Prednisolone 30–40 mg/d × 5d | COPD exacerbation — moderate to severe; based on Leuppi 2013 REDUCE trial and predecessors | Fewer treatment failures, shorter hospital stay vs. placebo; 5-day course non-inferior to 14-day course for re-exacerbation (REDUCE trial, Leuppi 2013). |
| Hench 1948–1949 | Cortisone (compound E) | Severe rheumatoid arthritis — clinical case series, Mayo Clinic | Dramatic remission in previously bedridden patients within 48–72 hours; launched the glucocorticoid era; led directly to the 1950 Nobel Prize in Physiology or Medicine. |
The Inflammatory Phase Principle: RECOVERY established that corticosteroids save lives in severe viral pneumonia only when hyperinflammation — not direct viral pathology — dominates. Dexamethasone showed no benefit and possible harm in patients not requiring supplemental oxygen, confirming the therapeutic window is the cytokine-storm phase of illness. Timing matters as much as dose: corticosteroids given during active viral replication may impair immune clearance; given in the subsequent inflammatory phase, they are life-saving. This principle likely applies across viral pneumonias and acute inflammatory lung diseases generally.
Side Effects
- High (systemic) HPA axis suppression — dose- and duration-dependent suppression of the hypothalamic-pituitary-adrenal axis; adrenal insufficiency on abrupt withdrawal; requires tapering for courses >3 weeks; risk varies with cumulative prednisolone-equivalent dose.
- High (systemic) Metabolic effects — hyperglycemia (new-onset or worsened in diabetic/pre-diabetic patients); weight gain and central fat redistribution; dyslipidemia; Cushingoid features (moon face, buffalo hump) with prolonged courses.
- High (systemic) Immunosuppression — impaired neutrophil trafficking, macrophage function, and T-cell responses; increased susceptibility to bacterial, fungal (PCP, aspergillosis), and viral opportunistic infections with high-dose or prolonged use; PCP prophylaxis indicated with prednisolone >20 mg/day >1 month.
- Moderate (long-term) Osteoporosis — suppress osteoblast activity, increase osteoclast activation, reduce calcium absorption; fracture risk increases significantly with >5 mg/day prednisolone equivalent for >3 months; bisphosphonate co-prescription recommended per FRAX risk guidelines.
- Moderate (systemic) Psychiatric effects — mood elevation, euphoria, irritability, insomnia; steroid-induced psychosis with high doses (uncommon); usually reversible on dose reduction; relevant history taking required before prescribing.
- Moderate (chronic) Cataracts and glaucoma — posterior subcapsular cataracts with chronic systemic use; elevated intraocular pressure with both systemic and high-dose ICS; ophthalmological monitoring for long-term users, particularly in patients with family history of glaucoma.
- Low (ICS) Oropharyngeal candidiasis — local ICS deposition promotes Candida growth in the oral cavity and pharynx; mitigated by spacer device use and mouth rinsing immediately after inhalation; lowest incidence with ciclesonide and dry powder inhalers.
- Low (ICS) Dysphonia — laryngeal myopathy from local ICS deposition on vocal cords; hoarseness and voice changes; more common with fluticasone propionate; spacers and dose reduction reduce risk substantially.
- Low (ICS, children) Growth suppression — dose-dependent modest effect on linear growth velocity with high-dose ICS; clinically minimal at low–medium recommended doses; risk-benefit strongly favors ICS over poorly controlled asthma in all but the smallest children.
Connections
References
- Hench PS, Kendall EC, Slocumb CH, Polley HF. The effect of a hormone of the adrenal cortex (17-hydroxy-11-dehydrocorticosterone: compound E) and of pituitary adrenocortical hormone in arthritis. Proc Staff Meet Mayo Clin. 1949;24(8):181-97. PubMed 18134783
- RECOVERY Collaborative Group. Dexamethasone in Hospitalized Patients with Covid-19. N Engl J Med. 2021;384(8):693-704. doi:10.1056/NEJMoa2021436 · PubMed 32678530
- Villar J, Ferrando C, Martínez D, et al. Dexamethasone treatment for the acute respiratory distress syndrome: a multicentre, randomised controlled trial (DEXA-ARDS). Lancet Respir Med. 2020;8(3):267-276. doi:10.1016/S2213-2600(19)30417-5
- Global Initiative for Asthma. Global Strategy for Asthma Management and Prevention. GINA; 2023. ginasthma.org/2023-gina-main-report/
- Global Initiative for Chronic Obstructive Lung Disease. Global Strategy for the Diagnosis, Management, and Prevention of COPD. GOLD; 2023. goldcopd.org/2023-gold-report-2/
- Leuppi JD, Schuetz P, Bingisser R, et al. Short-term vs conventional glucocorticoid therapy in acute exacerbations of chronic obstructive pulmonary disease (REDUCE). JAMA. 2013;309(21):2223-31. doi:10.1001/jama.2013.5023
- Barnes PJ. Glucocorticosteroids. Handb Exp Pharmacol. 2017;237:93-115. Comprehensive review of genomic and non-genomic mechanisms of corticosteroid action in respiratory disease.