The conversion (based on anti-inflammatory potency) is described with a great deal of variability in the literature.1-4 This calculator uses the following anti-inflammatory potencies to convert between different corticosteroid compounds:
Note that biological half-life is different than plasma half-life. Plasma half-life does not accurately reflect a corticosteroid's duration of action in vivo. The following qualitative biological half-lives are used in the table above:
Fludrocortisone (Fluorinef®) is used for its mineralocorticoid activity (causing increased reabsorption of sodium and loss of potassium/hydrogen). Although fludrocortisone technically possesses a small degree of anti-inflammatory activity (1/10th that of hydrocortisone), this effect is negibile at normal therapeutic doses of fludrocortisone (such as 0.05 to 0.2 mg per day). For this reason, fludrocortisone cannot realistically be converted to another corticosteroid on the basis of anti-inflammatory potency.