Corticosteroid converter

Switching a patient from one systemic corticosteroid to another is a daily task in clinics, hospital pharmacies, discharge planning, and exam-prep tables, and the milligram arithmetic is easy to get wrong when agents differ tenfold in anti-inflammatory potency. This corticosteroid dose equivalent calculator accepts a recognized drug name, a finite milligram dose, and a target steroid type, then returns the equivalent dose in milligrams using a fixed conversion table anchored on hydrocortisone twenty milligrams. Prednisone and prednisolone sit at five milligrams, methylprednisolone and triamcinolone at four, dexamethasone and betamethasone at zero point seven five, cortisone at twenty-five, deflazacort at six, and paramethasone at two.

What corticosteroid dose equivalence means

Corticosteroid dose equivalence is the textbook conversion that answers a practical question: if someone is taking a given milligram amount of one systemic glucocorticoid, what milligram amount of another agent matches the same anti-inflammatory glucocorticoid effect. The conversion is not a chemical identity and it is not a pharmacokinetic simulation. It is a published ratio table anchored on hydrocortisone, historically assigned twenty milligrams as the reference equivalent dose.

In that table five milligrams of prednisone or prednisolone, four milligrams of methylprednisolone or triamcinolone, and zero point seven five milligrams of dexamethasone or betamethasone are treated as anti-inflammatory matches for those twenty milligrams of hydrocortisone. Cortisone sits at twenty-five milligrams because it is a less potent precursor, deflazacort at six milligrams, and paramethasone at two milligrams. This capability applies that table as a pure ratio: equivalent dose in milligrams equals the source dose multiplied by the target agent's equivalent milligrams divided by the source agent's equivalent milligrams.

The result is a single milligram figure for the target drug, returned with the canonical names, the table rows used, and the conversion factor so a reviewer can recompute the arithmetic by hand. Mineralocorticoid potency, biological half-life, plasma protein binding, first-pass activation of prednisone to prednisolone, and topical or inhaled local activity are outside this ratio. Those properties matter clinically and they are not encoded here, which is why the output is labelled equivalent milligrams rather than a recommended prescription.

Use the number as a transparent starting conversion between named systemic corticosteroids, then apply clinical judgment, taper schedules, and local formulary rules on top of it.

Where equivalent-dose conversions belong—and where they do not

Hospital pharmacists converting a ward prednisolone taper to an equivalent hydrocortisone infusion need a single, auditable milligram figure rather than a spreadsheet cell that drifted between shifts. Discharge teams mapping a dexamethasone course back onto oral prednisone for the community prescription use the same ratio so the outpatient dose is not an order-of-magnitude error. Research coordinators batch-converting historical glucocorticoid exposures into prednisone-equivalent milligrams for cohort analysis need a closed table and a deterministic factor, not a model that changes between runs.

The conversion does not replace a prescriber: it does not taper, it does not adjust for hepatic activation of prednisone, it does not convert inhaled budesonide or topical clobetasol, and it does not report mineralocorticoid activity. Failed validation does not consume balance. Treat the output as anti-inflammatory milligram equivalence against the hydrocortisone twenty milligram table, then apply local protocol for duration, route, and monitoring.