Exam 5: Adrenal Corticosteroid Part 2 Flashcards
What are the therapeutic applications of GC agonists?
- Adrenal insufficiency (Addisons)
- Inflammatory disorders
- Autoimmune (Rheumatoid arthritis, IB, MS)
What are the therapeutic applications of GC antagonists?
Cushing’s syndrome and disease
What is the principal naturally occurring steroid?
Hydrocortisone (cortisol)
Describe the properties of hydrocortisone?
- Often taken orally
- A soluble salt can be given IV for rapid effect in an emergency
- A suspension (hydrocortisone acetate) can also be given directly into a joint
What is prednisone?
A prodrug that is converted into prednisolone in the liver
What is the therapeutic use for prednisolone?
An anti-inflammatory glucocorticoid, biologically active that has little sodium-retaining activity
What is an example of flurinated GC?
Triamcinolone
What is the use for Triamcinolone?
No sodium retaining (mineralocorticoid) effect, but has the disadvantage that muscle wasting may occasionally be severe and anorexia and mental depression may be more common when used at higher doses
What is Dexamethasone and Betamethasone?
- Powerful anti-inflammatory steroid
- Longer acting than prednisolone used for oral, otic, injectable, and topical
What are replacement glucocorticoid therapy used to treat?
- Acute adrenal insufficiency
- Chronic adrenal insufficiency (Addisons)
- Gongenital adrenal hyperplasia (autosomal)
How can glucocorticoid pharmacotherapy used for non-endocrine diseases?
Dramatic improvements but produce severe adverse effects
What is the primary mineralocorticoids?
Aldosterone
What is aldosterone used for?
Salt-retaining, rapidly inactivated by first-pass metabolism in the liver, and no place in routine therapeutics
What is fludrocortisone used for?
- Mineralcorticoid
- Long-acting fluorinated steroid that has a large sodium-retaining effect in relation to its anti-inflammatory action
- Replaces aldosterone where the adrenal cortex is destroyed and hydrocortisone is not sufficient to normalize sodium and water
- Used in patients with autonomic neuropathy
What is an adrenal or Addison crisis?
An acute adrenocortical insufficiency which may represent an endocrine emergency
What causes an adrenal crisis?
HPA-axis suppression brought on by chronic use of exogenous glucocorticoids and abrupt withdrawal
What is the treatment for Addison?
Hydrocortisone, cortisone, prednisone
What is the goal for Addison’s drug treatment?
Mimick normal diurnal adrenal rhythm
Why is hydrocortisone used for Addison?
It has both glucocorticoid and mineralocorticoid activity
What is Cushing’s?
Too much cortisol is made over a long period of time
What is the difference between exogenous and endogenous Cushing’s?
Ex: long term treatment with corticosteriod
En: Caused by tumors or adenoma (excessive ACTH)
How can pituitary tumors or adenomas cause Cushing?
noncancerous growths on the pituitary gland which make excessive ACTH, causing the adrenals to make too much cortisol
How can ectopic ACTH syndrome cause Cushing?
Tumors in other tissues that make ACTH. Tumors most commonly occur in the lungs
How can adrenal tumors cause Cushing’s?
Too much cortisol
How can we diagnose Cushing’s?
- 24 hr urinary free-cortisol test
- Low-dose dexamethasone suppression test
What is the 24 hr urinary free-cortisol test?
- Collect urine over a 24-hour period and test cortisol levels.
- Higher than normal cortisol levels suggest Cushing’s syndrome.
What is the Low-dose dexamethasone suppression test?
Cortisol levels in the blood should be suppressed after taking dexamethasone. Elevated cortisol levels suggest Cushing’s syndrome.
What are the treatments of Cushing’s?
- Surgery
- Radiation therapy
- Steroidogenic inhibitors
What are steroidogenic inhibitors?
- Inhibit enzymes required for the synthesis of corticosterone and cortisol
- Inhibition of the mitochondrial enzyme, 11-beta-hydroxylase is the most common drug target
What is metyrapone?
- Drug treatment for Cushing’s that inhibits cortisol synthesis
- Inhibits 11-beta-hydroxylase, inhibiting synthesis of cortisol from 11-deoxycortisol and corticosterone from desoxycorticosterone in the adrenal gland
What are the side effects of Metyrapone?
Nausea and vomiting, vertigo, headache, dizziness, abdominal discomfort, and allergic rashes
What is Osilodrostat?
Potent cortisol synthesis inhibitor that blocks the enzyme 11-beta-hydroxylase to interrupt the last step of the cortisol synthesis pathway (Cushing)
How does ketoconazole treat Cushing?
- Used to treat fungal infections too
- inhibitor of mitochondrial P450 enzymes systems (The 11-hydroxylase step is carried out by P450-dependent mitochondrial enzymes)
How does Mitotane treat Cushing’s?
- a steroid inhibitor and antineoplastic agent used for adrenocortical carcinoma and Cushing’s syndrome
- Inhibits 11-hydroxylation and pregnenolone synthesis from cholesterol in the adrenal cortex
- Reduces synthesis of cortisol and corticosterone
- Mitotane may cause serious, life-threatening adverse reactions
What is Pasireotide?
Somatostatin analog that acts via somatostatin receptors to inhibit the secretion of corticotropin from pituitary adenomas in patients with Cushing’s syndrome