Dexamethasone Sodium Phosphate
Common Brand Names: Decadron, Hexadrol, Dalalone
Therapeutic Class: A long-acting synthetic glucocorticosteroid with immunosuppressive and anti-inflammatory properties.
Common Injectable Dosage Forms:
Solution for Injection: 4 mg/mL (1 mL, 5 mL, 30 mL) and 10 mg/mL (10 mL)
For the treatment of shock: 1-6 mg/kg as a single injection, or 40 mg initially followed by repeated doses every 4-6 hours. Alternative therapy recommended may be an initial bolus of 20 mg, followed by a continuous infusion of 3 mg/kg/day.
For cerebral edema: An initial dose of 10 mg followed by 4 mg every 6 hours is recommended with dosage reductions after 2-4 days. The dose should be tapered over the next 5-7 days.
As an adjunct to prevention of chemotherapy-induced emesis: 10-20 mg may be given before administration of the agent.
A dosage of 0.15 mg/kg four times daily has been given to infants and children with bacterial meningitis for the first 4 days of antibacterial therapy.
Administration and Stability:
Dexamethasone may be given undiluted both for deep IM injection into a large muscle, or by direct, slow IV injection. Administer as a 5–10-minute bolus, rapid injection is associated with a high incidence of perineal discomfort. pH 7-8.5
Pharmacology/Pharmacokinetics:
Pharmacology of glucocorticoids is complex, and the drugs affect almost all body systems. Administered systemically they depress the hypothalamic-pituitary-adrenal axis (HPA), which in turn suppresses anti-inflammatory activity, promotes protein catabolism and gluconeogenesis, and stimulates erythroid cells in the bone marrow. The drugs are rapidly distributed to most tissues in the body following administration and metabolic effects are noted for periods long after elimination. They are metabolized by the liver and other tissues and excreted in both the urine and bile.
Drug and Lab Interactions:
Drugs such as BARBITURATES, PHENYTOIN, and RIFAMPIN may increase glucocorticoid metabolism by inducing hepatic enzymes. Concomitant use of NSAIDs may increase risk of ulcerogenesis. Concomitant use of other potassium-wasting drugs (I.e., thiazides, furosemide, etc.) increases risk of serum potassium depletion. Glucocorticoids also may interfere with skin test reactions and produce false-negative results in the nitroblue tetrazolium test for systemic bacterial infections.
Contraindications/Precautions:
Glucocorticoids should be used with caution in patients at risk for infective processes and should be monitored regularly for signs of infection. Unless used in life-threatening situations, they should be avoided in patients with active peptic ulcer diseases. Caution should be exercised in use for patients receiving anticholinesterases for myasthenia gravis, those with hypothyroidism or cirrhosis, and in patients with a known hypersensitivity to other corticosteroids. Pregnancy Category C.
Monitoring Parameters:
Hemoglobin, occult blood loss, serum potassium and glucose, intraocular pressure is use >6 weeks.
Adverse Effects:
Adverse effects include arrhythmias, premature ventricular contractions, nervousness, insomnia, irritability, hyperkinesia, psychosis, Cushing’s hyperthyroidism, hypercalcemia, peptic ulcers, GI bleeding, pancreatitis, vaginitis, glaucoma, cataracts, pulmonary edema, cutaneous reactions, lipodystrophy, and osteoporosis.
Common Clinical Applications:
Used extensively for the treatment of pulmonary diseases such as asthma and croup, septic shock, and cerebral edema.
