Adrenal Drugs Flashcards
Cosyntropin (Cortrosyn)
synthetic peptide, corresponds to residues 1 to 24 of human ACTH and is the agent of choice to test HPA axis
11B Hydroxysteroid dehydrogenase
Cortisol –> Cortisone
Cortisone doesn’t bind to the mineralocorticoid receptor
Corticosteroid effect on Lipid Metabolism
Induces lipolysis-free fatty acids
Redistribution of fat- increased fat in the neck- buffalo hump- and in the face- moon face. coupled with loss of fat in the extremities
Short acting glucocorticoids
Act for 8-12 hours
Hydrocortisone
Cortisone- must be metabolized in the liver reduced to 11 B hydroxy derivative to be active
Equal ratio of anti-inflammatory effects vs salt retaining effect
Intermediate acting Glucocorticoids
act for 18-36 hours Prednisone- must be metabolized in liver reduced to 11 B hydroxy derivative to be active Methylprednisolone Triamcinolone More potent than short acting drugs Very low salt retaining effect
Long Lasting Glucocorticoids
Betamethasone
Dexamethasone
Most potent
completely void of salt- retaining effects (long term and high doses may bind to mineralocorticoid receptor)
Toxicity of Adrenocortical Steroids
Withdrawal of therapy can result in flare-up of underlying disease
Most severe complication- Acute Adrenal insufficiency- results from too rapid withdrawal of corticosteroids
Corticosteroid Inhibitors
Aminoglutethimide
Ketoconazole
Spironolactone
Eplerenone
Aminoglutethimide
Inhibits P450 SCC enzyme (RLS)
used to treat Cushing’s Disease
Ketoconazole
Inhibits 17-alpha hydroxylase and C17-20 lyase. strongly inhibits all gonadal and adrenal steroid hormone synthesis
Used to treat prostate cancer and Cushing’s
Spironolactone
Blocks aldosterone receptors and inhibits sodium reabsorption, and blocks androgen receptors
Eplerenone
Binds to the mineralocorticoid receptors where it acts as an aldosterone agonist. Does not block androgen receptors
Does not cause gynecomastia
