How it's calculated
Dexamethasone dosing varies substantially by indication rather than following one flat mg/kg figure — select the indication to see its specific standard dose, route, and duration.
Dosing summary by indication
| Indication | Dose | Route |
|---|---|---|
| Croup | 0.15-0.6 mg/kg single dose | Oral or IM |
| COVID-19 (on oxygen) | 6 mg once daily, up to 10 days | Oral or IV |
| Vasogenic cerebral oedema | 10 mg loading, then 4 mg every 6h | IV/IM |
| Antenatal corticosteroids | 6 mg every 12h × 4 doses | IM |
Clinical use
- In croup, a single dose reduces the severity and duration of symptoms and the need for further intervention, even in relatively mild cases.
- The COVID-19 dose and duration reflect the RECOVERY trial regimen, which showed a mortality benefit specifically in patients requiring supplemental oxygen or ventilation — not in patients with milder disease not requiring oxygen.
- For antenatal corticosteroids, dexamethasone is an accepted alternative to betamethasone (the more traditionally used agent in some regions) when anticipating preterm birth within the guideline-specified gestational-age window.
Frequently asked questions
Why is croup dosing given as a range rather than one number?
0.15 mg/kg is often sufficient for mild-to-moderate croup, while the higher end of the range (up to 0.6 mg/kg) is reserved for more severe presentations — the exact dose used depends on clinical severity, not just weight.
Does dexamethasone help all COVID-19 patients?
No — benefit was specifically shown in patients requiring supplemental oxygen or ventilatory support; steroids are not recommended for patients with mild disease not requiring oxygen, where they may be harmful.
Why use dexamethasone instead of betamethasone for antenatal corticosteroids?
Both are accepted options with broadly similar efficacy for fetal lung maturation; the choice often comes down to local availability and institutional protocol rather than a strong clinical preference for one over the other.
References
- RECOVERY Collaborative Group. Dexamethasone in Hospitalized Patients with Covid-19. N Engl J Med. 2021;384:693-704.
- American Academy of Pediatrics. Clinical Practice Guideline — Croup.
- ACOG Practice Bulletin — Antenatal Corticosteroid Therapy for Fetal Maturation.