Learning Center/Pharmacology/Dexamethasone

Dexamethasone

Decadron / Dexasone

corticosteroid systemicIV · IM · oralOnset: 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

Clinical Pearls

Single-dose oral or IM dexamethasone is first-line treatment for croup
No mineralocorticoid activity — does not cause fluid retention (unlike prednisone)
Long half-life means single dose is often sufficient for croup
Pre-extubation dexamethasone reduces post-extubation stridor but is controversial for routine use
RECOVERY trial: dexamethasone 6 mg/day × 10 days reduced mortality in ventilated COVID-19 patients

Mnemonic

💡 DEX = Duration EXtended (36–72 hr), used for croup and extubation

NBRC High-Yield

Drug of choice for croup: 0.6 mg/kg single dose (max 10 mg)
No mineralocorticoid activity — no fluid retention
Long duration: 36–72 hours
Used for post-extubation stridor prophylaxis
RECOVERY trial: reduces mortality in severe COVID-19
25–30× potency of cortisol

← 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)

Clinical Pearls

Single-dose oral or IM dexamethasone is first-line treatment for croup

No mineralocorticoid activity — does not cause fluid retention (unlike prednisone)

Long half-life means single dose is often sufficient for croup

Pre-extubation dexamethasone reduces post-extubation stridor but is controversial for routine use

RECOVERY trial: dexamethasone 6 mg/day × 10 days reduced mortality in ventilated COVID-19 patients