====== Dexamethasone ======

===== Classification =====
  * Long-acting systemic glucocorticoid
  * High-potency corticosteroid

Parent class:
  * [[endocrine:drug_classes:corticosteroids|Corticosteroids]]

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===== Mechanism of Action =====

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:
  * [[endocrine:physiology:glucocorticoid_signaling|Glucocorticoid Signaling]]

It has **no mineralocorticoid activity**.

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===== Pharmacologic Characteristics =====

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

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===== Indications =====

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

See:
  * [[respiratory:clinical:asthma|Asthma]]
  * [[endocrine:physiology:hpa_axis|HPA Axis Physiology]]

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===== Dosing =====

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.

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===== Adverse Effects =====

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.

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===== Clinical Pearls =====

  * 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.

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===== Potency Comparison =====

Compared to prednisone:

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

See:
  * [[endocrine:drugs:prednisone|Prednisone]]
  * [[endocrine:drug_classes:corticosteroids|Corticosteroid Class Overview]]

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===== Related Pages =====

  * [[endocrine:drug_classes:corticosteroids|Corticosteroids]]
  * [[endocrine:physiology:glucocorticoid_signaling|Glucocorticoid Signaling]]