Dexamethasone: Uses, Dosage & Side Effects

10 min read

Quick Facts

What Is Dexamethasone?

Dexamethasone is a long-acting synthetic glucocorticoid approximately 25-30 times more potent than hydrocortisone. It suppresses inflammation and immune responses through multiple mechanisms.

How Dexamethasone Works
Dexamethasone binds to glucocorticoid receptors in the cytoplasm, translocating to the nucleus where it modulates gene transcription. This results in suppression of pro-inflammatory cytokine production, reduced neutrophil recruitment, decreased vascular permeability, and immunosuppression.

Indications

  • Cerebral edema (particularly perilesional edema; 4 mg IV/IM every 6 hours)
  • Acute respiratory conditions (croup, epiglottitis, ARDS)
  • Severe allergic reactions/anaphylaxis (adjunctive)
  • Autoimmune/inflammatory conditions (lupus, polymyalgia rheumatica)
  • Adrenocortical insufficiency (replacement)
  • Inflammatory bowel disease (flare management)
  • Severe COVID-19 (6 mg daily per RECOVERY trial)
  • Lymphoma (as part of combination regimens: CHOP, R-CHOP)
  • Nausea from chemotherapy (adjunctive)

Dosage and Administration

Highly variable by indication:

Anti-inflammatory/Immunosuppression:

  • Initial: 0.75-3 mg daily in divided doses
  • Maintenance: 0.5-1.5 mg daily (adjust based on response)

Cerebral Edema:

  • Loading: 10 mg IV/IM
  • Maintenance: 4 mg IV/IM every 6 hours for 2-4 days, then taper

Severe COVID-19:

  • 6 mg daily for 10 days or until hospital discharge (per RECOVERY trial)

Croup/Epiglottitis:

  • 0.6 mg/kg (typical: 10-12 mg) as single dose

Adrenocortical Insufficiency:

  • 0.5-0.75 mg daily in divided doses
Clinical Note
Long half-life (36-72 hours) allows once or twice-daily dosing. Taper gradually after prolonged courses to avoid adrenal insufficiency. Monitor for infection, hyperglycemia, osteoporosis with chronic use. More potent than prednisone; dose equivalency approximately 1 mg dexamethasone = 7.5 mg prednisone.

Side Effects

Common: Hyperglycemia, increased appetite, insomnia, mood changes, acne, hirsutism, weight gain Serious: Immunosuppression (infections including opportunistic), osteoporosis/osteonecrosis, adrenal suppression, hypertension, hypokalemia, psychiatric symptoms (psychosis, depression), GI perforation (with NSAIDs), cataracts

Warning
Chronic corticosteroid use carries significant morbidity including osteoporosis (especially with doses >7.5 mg daily for >3 months), osteonecrosis, opportunistic infections, and adrenal insufficiency. Vaccination status should be assessed prior to initiating long-term therapy. Live vaccines contraindicated during immunosuppression.

Contraindications

  • Systemic fungal infections (except histoplasmosis)
  • Live vaccine administration during immunosuppression
  • Uncontrolled infection (relative; may be indicated in severe inflammation)
  • Vaccinia, varicella, measles exposure (relative)
  • Cerebral malaria (may increase mortality)

Drug Interactions

  • NSAIDs: increased GI ulceration risk; monitor closely
  • Anticonvulsants (phenytoin, carbamazepine): increase dexamethasone metabolism
  • Rifampin: decreases dexamethasone levels
  • ACE inhibitors: additive hypokalemia risk
  • Antidiabetic agents: hyperglycemia may require dose adjustment

Key Clinical Evidence

RECOVERY trial (Lancet 2020) showed 6 mg dexamethasone daily reduced mortality in severe COVID-19 by 28%. Cerebral edema management in brain tumors: standard of care. Prolonged use (>3 weeks) carries significant adverse effect profile requiring careful risk-benefit assessment.

Monitoring Parameters

  • Baseline assessment before initiating therapy
  • Regular clinical follow-up per indication
  • Laboratory parameters as specified in sections above
  • Drug interaction screening at each visit

Special Populations

Dosing adjustments may be necessary in:

  • Renal impairment
  • Hepatic impairment
  • Elderly patients
  • Pregnancy and lactation
  • Pediatric patients

Patient Counseling

  • Take exactly as directed; do not modify dose without consulting healthcare provider
  • Report any unusual symptoms or adverse effects
  • Maintain regular follow-up appointments
  • Store at room temperature away from moisture and light
  • Keep out of reach of children

Disclaimer: This information is for educational purposes only and should not substitute for professional medical advice. Always consult with a qualified healthcare provider before starting, stopping, or modifying any medication.

Sources

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Last updated: 2024-01-01Sources: 2

The content on Medical Atlas is for informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider.