How to remember steroid dose-equivalence

The most common steroids used in clinical practice include Prednisone, Methylprednisone, Hydrocortisone & Dexamethasone. It’s useful to know the dose conversion from one form to another – for example, to change from oral to a different IV form, or if a hospital runs out of one form of steroid in their inventory.

I remember the dose-equivalence with this simple maths equation :

5 X 4 = 20 x 1

From left to right, the names start in a reverse alphabetical order to remember the names of 4 common steroids :

Prednisone (5) –> Methyprednisone (4) — > Hydrocortisone (20) –> Dexamethasone (1)!

So….5mg of Prednisone is the same as 4mg Methyprednisone (Solu-Medrol) , is the same as 20mg of Hydrocortisone , is the same as 1 mg of Decadron (roughly 1mg, ideally 0.75mg ). It’s easy to remember that Hydrocortisone is the least potent , so needs highest dose, while Dexamethasone is the most potent and needs the lowest dose.

So let’s say if you wanted to start someone on stress dose steroids with the standard 50mg IV Hydrocortisone every 6 hours (i.e. 200mg in 24 hours) in septic shock not responding to pressors/antibiotics/fluids, and your only available option to use was IV Dexamethasone at your hospital/ER, then using the above , you know you will need at least 10mg Dexamethasone IV in 24 hours !