Hydrocortisone 200 mg Equivalency to Prednisone
Hydrocortisone 200 mg is equivalent to prednisone 50 mg, based on the established 4:1 conversion ratio. 1, 2
Standard Conversion Ratio
The universally accepted conversion is 20 mg hydrocortisone = 5 mg prednisone (4:1 ratio), which means 200 mg hydrocortisone equals 50 mg prednisone. 3, 1, 2
This 4:1 ratio is consistently endorsed across multiple authoritative guidelines including the Association of Anaesthetists, Royal College of Physicians, Society for Endocrinology UK, and ASCO. 3, 1
The FDA drug label for hydrocortisone explicitly states: "20 mg of hydrocortisone is equivalent to 5 mg of prednisolone" when discussing multiple sclerosis treatment protocols. 2
Clinical Context Supporting This Equivalency
The 200 mg hydrocortisone dose represents the maximum daily adrenal output during physiological stress (such as major surgery), making the 50 mg prednisone equivalent clinically relevant for stress-dose coverage. 3, 1
Perioperative guidelines consistently use hydrocortisone 200 mg/24 hours as the standard stress-dose regimen, which can be substituted with equivalent prednisone dosing when oral administration is feasible. 3
Alternative corticosteroid equivalencies that validate this ratio include: prednisone 60 mg = hydrocortisone 240 mg, which maintains the same 4:1 relationship. 1
Important Clinical Caveats
While the 4:1 ratio reflects equivalent anti-inflammatory potency, hydrocortisone has approximately 25 times MORE mineralocorticoid activity than prednisolone. 1 This difference is critical in primary adrenal insufficiency where mineralocorticoid replacement (fludrocortisone) must be added when using prednisone. 3
The conversion assumes bioequivalence for anti-inflammatory effects but does not account for differences in duration of action—hydrocortisone has a shorter half-life (~90 minutes) compared to prednisone, requiring more frequent dosing to maintain physiologic cortisol rhythms. 3
For patients with primary adrenal insufficiency, hydrocortisone is preferred over prednisone because it allows recreation of diurnal cortisol rhythm and provides necessary mineralocorticoid activity. 3