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Dexamethasone

Brand names: Decadron (brand discontinued), Hemady

Dexamethasone is a strong, long-acting steroid used for croup, severe asthma, swelling, nausea with cancer treatment, and more.

Brand namesDecadron (brand discontinued), Hemady
Type of medicineCorticosteroid (strong steroid)
Prescription?Prescription
ImportantThis page is general information, not a prescription. Don't start, stop, or change a medicine without talking to your provider or pharmacist.

Overview

A single dose is common for croup in children.

What it's used for

  • Croup
  • Severe asthma and allergic reactions
  • Brain swelling
  • Nausea from chemotherapy
  • Severe COVID-19 needing oxygen (in the hospital)
  • Some cancers and autoimmune diseases

How to take it

  • Take it with food in the morning.
  • For longer courses, don't stop suddenly.

Your dose depends on your health and other medicines. Always follow your prescription label, and ask your pharmacist if anything is unclear.

Side effects

Common side effects

  • Increased appetite
  • Trouble sleeping
  • Mood changes
  • Higher blood sugar
Call 911Black or bloody stools or vomiting blood
Call your provider todayFever or signs of infection
Call your provider todayVery high blood sugar
Call your provider todaySevere mood changes or confusion

Warnings

  • It lowers your ability to fight infection.
  • People with diabetes should check blood sugar more often.

Other medicines, foods, and alcohol

  • NSAIDs raise ulcer risk.
  • Many medicines change its level, including some seizure medicines and antifungals.

Tell your provider and pharmacist about every medicine, vitamin, and supplement you take.

Pregnancy and breastfeeding

Sometimes used in pregnancy (for example, to help a premature baby's lungs). Talk with your provider.

Missed doses, overdose, and storage

If you miss a dose

Take it as soon as you remember, unless it's almost time for your next dose. Then skip the missed dose. Don't take two doses at once.

If someone takes too much

Call Poison Control at 1-800-222-1222 or get help online at poison.org. Call 911 if the person collapses, has a seizure, has trouble breathing, or can't be woken.

Storing it

Store at room temperature, away from heat and moisture (not in the bathroom), and out of reach of children and pets.

Conditions it's used for

Sources

Last updated 2026-11-13.