Dexamethasone Phosphate (Decadron)

Anesthesia Implications

Classification: Glucocorticosteroid
Therapeutic Effects: PONV prophylaxis, steroid replacement
Time to Onset: 1-2 minutes
Time to Peak: 12-24 hours
Duration: 36-54 hours

Contraindications

Diabetes
Hyperglycemia
Any patient that just received or is soon to receive a live virus vaccine

Use with caution in patients with:
Heart failure, hypothyroidism, history of stroke, cirrhosis, myasthenia gravis, new intestinal anastamosis, history of seizures, fungal/viral infections, psychosis, peptic ulcers

Primary Considerations

Uses – Most common use is post operative nausea and vomiting (PONV) prophylaxis and prevention of airway edema. Alone, dexamethasone reduces PONV by approximately 33% . Combined with zofran and other PONV prophylactics, the effects are ADDITIVE. Decadron is most effective if given before induction (versus at the end of the surgery). Other uses can include treating increased intracranial pressure (ICP), cerebral edema, aspiration pneumonitis, bronchial asthma, and allergic reactions.

Local anesthetic adjuvant – Combined with local anesthetics, Decadron appears to improve the quality and duration of peripheral nerve blockade. The effect appears to be the same when decadron is administered by IV in an approximate timeframe as the peripheral nerve block. However, the studies show that when utilizing intravenous regional anesthesia (IVRA), such as a bier block, decadron only had effect when combined with the local anesthetic.

Check blood glucose and diabetic status before administering – Decadron will raise blood sugar levels. This is the primary side-effect.

Inhibitory effects – decadron may inhibit/suppress the Hypothalamic-pituitary-adrenal (HPA) axis, reduce the number/activity of inflammatory cells, and inhibit bronchoconstriction mechanisms. Immunosuppressive effects of a single dose is negligible, but the practitioner should still be aware that there may be SOME effect.

Drug interactions – Decadron enhances the effects of beta-adrenergic drugs. Metabolism of Decadron is enhanced by phenytoin, phenobarbital, rifampin, and ephedrine. Insulin requirements are increased by Decadron. Weakness in patients with myasthenia gravis can be exacerbated if the patient is also taking anticholinesterase agents such as pyridostigmine. Potassium wasting diuretic effects in drugs such as furosemide will be enhanced. If given to patients also taking NSAIDS, dexamethasone can increase the risk of GI bleeding.

IV push dose

Adult PONV prophylaxis: 4-8 mg
Adult Peripheral nerve blockade adjuvant: 4-10 mg
Adult Airway Edema: 0.2-0.5 mg/kg every 6 hours for 4-6 doses or PRN.
Adult Cerebral Edema or increased ICP: 0.5-1.5 mg/kg, then 0.2-0.5 mg/kg every 6 hours

Pediatric PONV prophylaxis: 0.1-0.15 mg/kg

Method of Action

Dexamethasone is a derivative (fluorinated) of prednisolone. It is approximately 7 times the potency of prednisolone. Binds to steroid receptors intracellularly. The exact intracellular site is unknown.

Metabolism

Hepatic