corticosteroid systemic

Dexamethasone

Decadron / Dexasone

Route: IV · IM · oral
Onset: 30–60 minutes (IV); 2 hours (IM/oral)
Duration: 36–72 hours (long-acting)

Mechanism of action

Potent synthetic glucocorticoid with no mineralocorticoid activity. 25–30× potency of cortisol. Penetrates CNS well. Long duration of action. Reduces inflammation and edema.

Dosing

Adult: Cerebral edema: 10 mg IV × 1, then 4 mg IV q6h. Post-extubation: 0.1–0.25 mg/kg IV × 1 (4–8 hours before planned extubation)
Pediatric: Croup: 0.6 mg/kg IM/oral × 1 (max 10 mg). Post-extubation: 0.25–0.5 mg/kg IV
Neonatal: 0.15 mg/kg IV q12h (BPD/extubation — use is controversial; DART trial)

Indications

Croup (laryngotracheobronchitis) — first-line oral/IM
Post-extubation stridor prophylaxis
Cerebral edema
Anaphylaxis (adjunct)
Airway edema before extubation attempts
COVID-19 (severe/critical) — reduces mortality

Contraindications

Systemic fungal infections
Live vaccines

Side effects

Hyperglycemia
Insomnia
Mood changes / agitation
GI upset
Adrenal suppression (prolonged)
No significant fluid retention (no mineralocorticoid activity)

Monitoring parameters

Blood glucose
Neurological status (cerebral edema patients)
Airway patency post-extubation
Croup symptoms (stridor, work of breathing)

Drug interactions

CYP3A4 inducers (rifampin — decreases effect)
NSAIDs (GI ulceration)
Antidiabetics

All Drugs

Dosing

Adult

Cerebral edema: 10 mg IV × 1, then 4 mg IV q6h. Post-extubation: 0.1–0.25 mg/kg IV × 1 (4–8 hours before planned extubation)

Pediatric

Croup: 0.6 mg/kg IM/oral × 1 (max 10 mg). Post-extubation: 0.25–0.5 mg/kg IV

Neonatal

0.15 mg/kg IV q12h (BPD/extubation — use is controversial; DART trial)