Dexamethasone
A potent glucocorticoid with almost no salt-retaining effect, used for brain swelling, severe inflammation, chemotherapy sickness and COVID-19.
Drug card
- Class
- Glucocorticoid
- How it works
- Activating glucocorticoid receptors, which switch off inflammatory genes
- Used for
- Brain swelling from tumors, surgery or injury
- Nausea and vomiting with cancer treatment
- Severe allergic conditions
- Rheumatoid arthritis and other rheumatic diseases
- Known for
- Adrenal suppression; stopping suddenly is dangerous
- Infections, with their signs masked
- High blood sugar
- Its name
- -metasone, -methasone means a corticosteroid (dexamethasone type)
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does dexamethasone work?
A synthetic adrenal corticosteroid with strong anti-inflammatory action. Besides binding nuclear glucocorticoid receptors, it interferes with NF-kB activation and apoptosis pathways. At doses with equal anti-inflammatory effect, it has almost none of the sodium-retaining activity of hydrocortisone.
Like other glucocorticoids: They enter cells and bind the glucocorticoid receptor; the activated complex moves to the nucleus, binds glucocorticoid response elements and changes which genes are read. Inflammatory cytokines and NF-kB signaling are damped, lymphocytes and eosinophils fall, and gluconeogenesis and protein breakdown rise. With long use they suppress ACTH release and so the adrenal glands' own output.
Uses
What is dexamethasone used for?
- Brain swelling from tumors, surgery or injury
- Nausea and vomiting with cancer treatment
- Severe allergic conditions
- Rheumatoid arthritis and other rheumatic diseases
- Lupus and other autoimmune diseases
- Severe COVID-19 in hospital
Side effects
Side effects of dexamethasone
- Adrenal suppression; stopping suddenly is dangerousKnown forSerious
- Infections, with their signs maskedKnown forSerious
- High blood sugarKnown for
- Mood changes, euphoria and psychosis
- Trouble sleeping
- Indigestion
- Osteoporosis and fracturesSerious
- Peptic ulcer, which can bleed or perforateSerious
- Cushingoid features: moon face, central fat
- Cataracts
- Glaucoma (raised eye pressure)Serious
- Weight gain
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Contraindicated in systemic fungal infections.
- After prolonged use, withdraw it gradually, and raise the dose during stress such as surgery or serious illness.
- It raises blood glucose, so insulin or other diabetes drugs may need increasing.
- Macrolides and other CYP3A4 inhibitors slow its clearance and enzyme inducers speed it; it can also blunt warfarin.
Good to know: Almost free of mineralocorticoid (salt-retaining) effect at anti-inflammatory doses, unlike hydrocortisone; widely used for cerebral edema and as an antiemetic in cancer care.
Remember it
A way to remember it
STEROIDS
- S
- Suppression of the adrenal glands
- T
- Thin bones (osteoporosis)
- E
- Eyes: cataracts and glaucoma
- R
- Raised blood sugar and blood pressure
- O
- Obesity of the trunk and a moon face (Cushingoid features)
- I
- Infections, with signs masked
- D
- Depression and other mood changes
- S
- Stomach (peptic) ulcers
Written for biofideX
Its name
-metasone, -methasone means corticosteroid (dexamethasone type)
Dexamethasone, betamethasone, beclometasone and mometasone share it; WHO files it under pred. US names keep the h (beclomethasone). Fluticasone ends in -casone.
- Every drug name stem
Its class
Glucocorticoids
Other glucocorticoids with a card:
Easily mixed up with inhaled corticosteroids and non-steroidal anti-inflammatory drugs.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- Dexamethasone tablets: label (DailyMed)
- Dexamethasone (NCI Thesaurus)
- About dexamethasone tablets and liquid (NHS)
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Thyroid, steroids and bones
Dexamethasone is one of 9 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
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