Steroid Equivalent Dose Converter

No. In Liu 2013's table, 4 mg of methylprednisolone is equivalent to 0.75 mg of dexamethasone, so dexamethasone is about 5 times as potent milligram for milligram. The same table gives dexamethasone 30 times hydrocortisone's glucocorticoid activity. Other references round differently: the Endotext table lists 0.8 mg of dexamethasone as equivalent to 20 mg of hydrocortisone. Switching mg-for-mg between these two drugs without converting first leads to large over- or under-dosing.

The equivalents in Liu 2013 are for oral or IV use, and the table's own footnote says relative potency for intra-ocular or intramuscular use may vary considerably. Topical, inhaled and joint injections behave differently again, so the calculator leaves them out.

It depends on the condition, and the prescriber decides. Liu 2013's table gives the general uses: hydrocortisone suits adrenal insufficiency because of its relatively high mineralocorticoid activity; prednisone's high glucocorticoid activity makes it useful for long-term treatment; dexamethasone is usually kept for short-term use in severe, acute conditions because of its high potency and long action. The same paper covers monitoring and tapering.

The ratios between drugs are the same, so 4 mg of methylprednisolone still matches 5 mg of prednisone. Dose selection is what differs: Liu 2013's paediatric tapering table works in hydrocortisone equivalents per square metre of body surface area, not adult flat doses. This tool converts a dose between drugs; it doesn't pick a child's dose. The BSA calculator and a paediatric dose reference cover that step.