• Long-acting systemic glucocorticoid
• High-potency corticosteroid

Parent class:

• Corticosteroids

Dexamethasone:

• Binds intracellular glucocorticoid receptors
• Alters gene transcription
• Strong suppression of cytokines (IL-1, IL-2, IL-6, TNF-α)
• Decreases prostaglandin and leukotriene production
• Reduces edema and inflammation

See full pathway:

• Glucocorticoid Signaling

It has no mineralocorticoid activity.

• Very high glucocorticoid potency
• Long half-life (36–72 hours)
• No sodium-retaining effects
• Strong HPA suppression

• Cerebral edema
• Severe inflammatory conditions
• Croup
• COVID-related inflammation
• Oncologic edema
• Diagnostic dexamethasone suppression test
• Adjunct in severe asthma exacerbation

See:

• Asthma
• HPA Axis Physiology

Highly indication-specific.

Common examples:

• Croup: single-dose therapy
• Cerebral edema: IV dosing
• Suppression testing: low-dose diagnostic regimen

Long duration allows once-daily or less frequent dosing.

Short-term:

• Hyperglycemia
• Mood changes
• Insomnia

Long-term:

• HPA suppression
• Osteoporosis
• Cushingoid features
• Muscle wasting
• Immunosuppression

Because of long half-life, suppression may persist longer than intermediate-acting steroids.

• No mineralocorticoid activity — preferred when fluid retention undesirable.
• Very potent; small doses have strong effects.
• Used in dexamethasone suppression testing.
• Long duration increases HPA suppression risk.
• Common in neurologic and oncologic inflammation.

Compared to prednisone:

• ~6–7 times more potent
• Longer acting
• No sodium retention

See:

• Prednisone
• Corticosteroid Class Overview

• Corticosteroids
• Glucocorticoid Signaling