Dexamethasone (Decadron) is synthetic adrenocortical steroid roughly 25 times more potent than hydrocortisone and devoid of mineralcorticoid (“sodium retaining”) properties. Therefore, it’s primarily used for long acting, anti-inflammatory effects.
In the ICU, I most commonly use dexamethasone for edema related to intracranial tumors as this medication has excellent blood-brain barrier penetration. I also see it ordered for everything from chemotherapy regimens and various dermatologic conditions to vasculitis and a myriad of rheumatic disorders.
In the OR, I use it as a prophylactic measure against nausea/vomiting in high risk patients, to help alleviate sore throat discomfort from extensive instrumentation in the airway, and to prolong the duration of peripheral nerve blocks. Based on its potency, 4 mg of intravenous (IV) dexamethasone is roughly 100 mg of IV hydrocortisone. In other words, a dose routinely used for nausea/vomiting prophylaxis when under general anesthesia is the equivalent of an interval stress dose of steroids (I usually do 100 mg IV hydrocortisone q8h). Obviously this doesn’t translate perfectly due to different pharmacokinetics and mineralcorticoid potencies, but it’s crazy to think about regardless!
Although all steroids come with a never-ending list of side effects (especially with long-term use), medications like dexamethasone still have significant benefits when used appropriately. In fact, it’s one of the medications in the World Health Organization’s List of Essential Medicines.
Drop me a comment below with questions! 🙂