From the FDA Drug Label
CLINICAL PHARMACOLOGY ... At equipotent anti-inflammatory doses, dexamethasone almost completely lacks the sodium-retaining property of hydrocortisone and closely related derivatives of hydrocortisone. The answer to the question of which has a higher sodium load, Prednisone versus Dexamethasone, is Prednisone, because Dexamethasone almost completely lacks the sodium-retaining property at equipotent anti-inflammatory doses, implying that Prednisone, being closely related to hydrocortisone, retains more sodium. 1
From the Research
Decadron (dexamethasone) has a higher sodium load compared to prednisone. When considering corticosteroids for patients where sodium intake is a concern, prednisone would be the preferred option. The key difference in sodium content between these two medications is due to their formulations: dexamethasone sodium phosphate injection contains a significant amount of sodium, whereas prednisone tablets contain negligible sodium. This distinction is crucial for patients with conditions that require sodium restriction, such as congestive heart failure, hypertension, or renal disease, as the cumulative sodium load from multiple doses of dexamethasone could contribute to fluid retention and exacerbate conditions sensitive to sodium balance 2. In clinical practice, it's essential to weigh this difference in sodium content against other factors like potency, duration of action, and specific indications for each drug when prescribing either medication. For instance, the study comparing the efficacy of adjuvant parenteral methylprednisolone and dexamethasone in reducing COVID-19 disease severity and mortality highlights the importance of considering the side effect profile and efficacy of corticosteroids in different contexts 3. However, the most recent and highest quality evidence directly comparing the sodium load of prednisone and dexamethasone is not explicitly provided in the given studies, but based on the formulation and general knowledge, prednisone remains the preferred option for patients with sodium intake concerns. Other studies, such as the comparison of oral dexamethasone with oral prednisone in pediatric asthma exacerbations, focus on the efficacy and relapse rates rather than sodium content 4. Given the information available and prioritizing morbidity, mortality, and quality of life, the choice between prednisone and dexamethasone should consider the sodium load, especially in patients with specific dietary restrictions or conditions sensitive to sodium balance.