Dexamethasone

Dexamethasone is a corticosteroid. which is approximately 30 times more potent than cortisol and 6–7 times more potent than prednisolone.

Three forms of Dexamethasone is available-

• Dexamethasone Sodium Phosphate
• Dexamethasone in Polyethylene glycol vehicle
• Dexamethasone-21-isonicotinate

The difference among formulations is that dexamethasone sodium phosphate is a water-soluble formulation that can be injected intravenously. Dexamethasone solution is in a polyethylene glycol vehicle that should not be administered rapidly intravenously; it can be given slowly. Dexamethasone-21-isonicotinate is only for intra-muscular (IM) use.

Group

Dexamethasone is grouped in Corticosteroids.

Mechanism of Action

Dexamethasone is act by inhibition of inflammatory cells and suppression of expression of inflammatory mediators.

Dose Rates

Dog and Cat: 0.1-1 mg/kg q12-24hrs IV IM SC PO

In the case of dogs and cats, dexamethasone is used at 0.1 mg/kg for anti-inflammatory action and at 1 mg/kg for immunosuppression. In the case of shock, it can be used up to 5 mg/kg of body weight.

Horse and Cattle: 0.1 mg/kg q12-24hrs IV IM SC

Indications

• Inflammation
• Immune suppression, Immune mediated diseases
• Dexamethasone use in Shock is controversial
• Adrenal Insufficiency
• Diagnostic test for adrenal functions
• Induction of parturition
• Ketosis
• Equine Asthma Syndrome (Bronchoconstriction caused by recurrent airway obstruction)
• Burns
• Arthritis, Laminitis, Dermatitis

Contraindications

• In infections and wound healing cases
• Diabetes
• Pregnant animals
• Renal failure patients

Interactions

• Cause severe Gastrointestinal Ulcers when given along with NSAIDs.

Adverse effects

• Polyphagia, Polydipsia and Polyuria
• Gastrointestinal Ulcers
• Delayed wound healing
• Secondary infections
• Hyperlipidemia
• HPA (Hypothalamic Pituitary Adrenal) Axis suppression
• Increase risk of Diabetes

Immunosuppression by Dexamethasone can lead to secondary infections, such as infections from Demodex spp., toxoplasmosis, fungal infections, and urinary tract infections (UTIs).

Toxicity

A high dose of dexamethasone in animals with neurologic disease can lead to excitotoxic cell death and oxidative injury.

Preparations

Injectables: 4.4 mg/mL, 5 mg/mL

Tablets: 0.5 mg, 2 mg, 4 mg

More about Dexamethasone for animals