Dexamethasone
9-fluoro-11β,17,21-trihydroxy-16α-methylpregna-1,4-diene-3,20-dione
Also known as: Decadron · Dexasone · Azium · Maxidex · Dexamethasone sodium phosphate · Dexamethasone base · Dexamethasone alcohol
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Audited v13 dosing evidence
Structured calculator evidenceEmergency glucocorticoid use in a ferret collapsed from suspected insulinoma
Verified clinician required
Governing clinical context (1)
- Has not been found to result in improved neurologic recovery or have other positive effects on post-arrest outcome. Thus, its use is not recommended, except in ferrets with collapse due to (suspected) insulinoma. May also be used to treat anaphylactic shock
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Dexamethasone is a highly potent, long-acting synthetic glucocorticoid widely used in veterinary medicine for its profound anti-inflammatory and immunosuppressive properties.
- Potency: It is approximately 25-30 times more potent than hydrocortisone (cortisol) and lacks any significant mineralocorticoid (water-retaining) activity.
- Formulations: It is available as an alcohol base or as a phosphate derivative (suspensions, solutions, or ointments). The anti-inflammatory efficacy of the alcohol form is generally superior to that of the phosphate derivative.
Clinical Pearl: Because of its long biological half-life (>36-72 hours) and lack of mineralocorticoid activity, dexamethasone is excellent for high-dose immunosuppressive therapy, acute allergic reactions, or diagnostic testing (e.g., low/high-dose dexamethasone suppression tests). However, it is not suitable for alternate-day maintenance therapy due to the high risk of profound hypothalamic-pituitary-adrenal (HPA) axis suppression.
Mechanism of action
Dexamethasone exerts its effects by diffusing across cell membranes and binding to specific cytosolic glucocorticoid receptors (GR).
- Transactivation: The receptor-ligand complex translocates to the nucleus → binds to glucocorticoid response elements (GREs) on DNA → upregulates the expression of anti-inflammatory proteins like lipocortin-1 (annexin A1). Lipocortin-1 inhibits phospholipase A2, thereby blocking the release of arachidonic acid and the subsequent synthesis of inflammatory prostaglandins and leukotrienes.
- Transrepression: It inhibits transcription factors such as NF-κB and AP-1 → downregulates the production of pro-inflammatory cytokines (e.g., IL-1, IL-6, TNF-α).
Safety & warnings
Contraindications
- Systemic fungal infections
- Active viral infections
- Corneal ulcers (especially for ophthalmic preparations)
- Concurrent use of NSAIDs
- Known hypersensitivity to the drug
Adverse effects
- Polyuria (PU) and Polydipsia (PD)
- Polyphagia (increased appetite)
- Panting (especially in dogs)
- Gastrointestinal ulceration or bleeding
- Iatrogenic hyperadrenocorticism (Cushing's syndrome) with chronic use
- Secondary infections due to immunosuppression
- Delayed wound healing
- Muscle wasting and weakness
Precautions
Use with extreme caution in patients with diabetes mellitus, renal disease, congestive heart failure, or active infections. Do not stop abruptly if used chronically; the dose must be tapered to avoid an Addisonian crisis (adrenal insufficiency). Avoid ophthalmic use if corneal ulceration is present.
Drug interactions
Significantly increased risk of severe gastrointestinal ulceration and bleeding.
Dexamethasone induces insulin resistance, antagonizing the hypoglycemic effect of insulin and increasing requirements in diabetic patients.
May induce hepatic enzymes, increasing the metabolism and clearance of dexamethasone.
Increased risk of hypokalemia.
Monitoring
- Clinical signs of disease resolution
- Water intake and urination (PU/PD)
- Appetite and body weight
- Blood glucose levels (especially in predisposed patients)
- Signs of gastrointestinal bleeding (melena, hematemesis)
- ACTH stimulation test (if assessing HPA axis suppression)
Pharmacokinetics
Half-life
Absorption
Well absorbed after oral administration. Phosphate and sodium phosphate esters are rapidly absorbed from IM or SC sites.
Distribution
Widely distributed throughout the body. Crosses the placenta and enters breast milk. Highly bound to plasma proteins (transcortin and albumin).
Metabolism
Metabolized primarily in the liver.
Elimination
Excreted primarily by the kidneys as inactive metabolites.
Overdose
Acute overdose is rarely life-threatening but may cause significant gastrointestinal upset, profound PU/PD, and panting. Chronic overdosage leads to iatrogenic hyperadrenocorticism (Cushing's syndrome), characterized by alopecia, pot-bellied appearance, muscle wasting, and immunosuppression. Treatment is supportive and requires gradual tapering of the drug.
Available products
Formulations
- Suspension
- Ointment
- Tablets
- Injectable solution
Human-labeled
- Dexamethasone Sodium Phosphate 0.1% Solution, 5 mL bottles
- Dexamethasone Phosphate 0.05% Ointment, 3.5 gram tubes
Regulatory status
No regulatory data for: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store at room temperature away from light and moisture. Keep containers tightly closed. Do not freeze liquid formulations.
Client information
Important Information for Pet Owners:
- Increased Thirst and Urination: Your pet will likely drink much more water and need to urinate more frequently. Ensure they always have access to fresh water and provide extra bathroom breaks to prevent accidents.
- Increased Appetite: Your pet may seem unusually hungry. Avoid overfeeding to prevent unwanted weight gain.
- Panting: Dogs may pant more than usual; this is a common and generally harmless side effect.
- Do Not Stop Abruptly: If your pet has been on this medication for more than a few days, do not stop giving it suddenly. The dose must be gradually tapered under veterinary supervision to allow your pet's body to resume its own natural steroid production.
Warning: Contact your veterinarian immediately if you notice dark, tarry stools, vomiting (especially with blood), or extreme lethargy, as these can be signs of stomach ulcers.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.