differences between steroids? (dex, hydro, solu, pred)

[bulldog]

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i used to know this in med school but what's the difference between the various steroids besides potency? i know some cross fetal barrier in pregnancy, and there were a few other subtleties. thanks.

 

[swpm]

i used to know this in med school but what's the difference between the various steroids besides potency? i know some cross fetal barrier in pregnancy, and there were a few other subtleties. thanks.

They differ in anti-inflammatory effects, mineralocorticoid effects, glucocorticoid effects, half-life, and route of administration.

For example, dexamethasone and betamethasone have essentially no mineralocorticoid effects, while fludrocortisone has minimal glucocorticoid effects. Dexamethasone's a great choice for use as an anti-inflammatory, but it'd be a poor choice for your septic patient with hypotension refractory to fluids & pressors.

All steroids are lipid soluble and would cross the placenta easily, but some placental enzyme (1-or-11-or-18-number-number-something-something-ase?) prevents most endogenous steroids from crossing in an active form. IIRC dexamethasone and betamethasone are poor substrates for that enzyme and cross quickly (which is why we can give them to moms in preterm labor to hasten fetal lung maturity).

The internet's probably full of charts that have tables showing the context-specific relative potency of each steroid.

 

[Pir8DeacDoc]

There is a nice chart in your "Tarascon Pocket Pharmacopeia" that should clear this up. It's in the section on endocrine.