SteroidPrescription only
Dexamethasone
Tablet or injection
Quick Summary
Dexamethasone is a long-acting, potent steroid.
Croup
Severe inflammation and allergies
Severe COVID-19
Medical Uses
Croup: A single dose.
Severe inflammation and allergies: As prescribed.
Severe COVID-19: In hospital for people needing oxygen.
How it's taken
Take exactly as prescribed, usually with food.
Your doctor decides the right dose for you and how long to take it.
Your doctor decides the right dose for you. Follow their instructions and the label.
Common Side Effects
High blood sugar
Common.
Sleep problems
And mood changes.
Indigestion
Take with food.
Interactions
NSAIDs
Stomach bleeding risk.
Diabetes medicines
May need adjusting.
Critical Warnings
Misuse
Black Box Warning: Not to be taken without prescription; it can cause serious harm, including fungal infections.
Don't stop suddenly
After long use.
Sources and further reading
Last updated 21 October 2026. For more detail, see these trusted health organisations.
- Dexamethasone: drug information(opens in a new tab) · MedlinePlus, US National Library of Medicine