Pharmacology of Corticosteroids and Steroid Antagonists Flashcards
What are the treatment goals when it comes to the pharmacology of corticosteroids?
- Reverse the clinical manifestations by reducing cortisol to normal
- Eradicate any tumor threatening the health
- Avoid permanent dependence on medication
- Avoid permanent hormone deficiency
What is the effect of glucocorticoids on the liver?
Increase glycogen storage
WHat is the effect of corticosteroids on the skeletal msucle?
Play a permissive role for catecholamine-induced glycogenokysis and/or inhibit insulin-stimulated glycogen synthesis
What causes Cushing’s disease?
Excess corticosteroids as a result of the adrenal/pituitary hyperfunction
What are the signs of Cushing’s syndrome?
Moon face
Obesity
Slow wound healing
Hirsutism
Hypokalemia
Fat distribution & deposition at the base of the neck
Weak muscles
What are the different types of Cushing’s disease?
- ACTH-dependent Cushing’s syndrome
- ACTH-independent Cushing’s syndrome
- Pseudo-Cushing syndrome
What are the causes of ACTH-dependent Cushing’s syndrome ?
- Cushing’s disease or ACTH secreting pituitary adenoma
Ectopic ACTH secretion
What are the causes of ACTH-independent Cushing’s syndrome?
- Adrenal adenoma
- Adrenal carcinoma
- Bilateral adrenal hyperplasia
- Iatrogenic Cushing’s syndrome (Exogenous Glucocorticoid exposure)
WHat are the causes of pseudo-Cushing’s syndrome?
Obesity
Alcoholism
Depression
What are the results of an inrease in cortisol levels?
- High BP
- Bone formation inhibition
- Anti-inflammatory
- Decreased immune function
- Increase gluconeogenesis, lipolysis, proteinlysis
What is the difference between Cushing’s disease and Cushing’s syndrome?
Cushing’s disease: Caused by a tumor on the pituitary gland that causes the gland to produce too much ACTH. ACTH is responsible for the production of cortisol –> Too much ACTH then causes the adrenal glands to produce too much cortisol hormone
Cushing’s syndrome: Due to causes outside the bod that increase the levels of cortisol, such as taking medication containing cortisol –> corticosteroids
What is the hypothalamic-pituitary-adrenal axis?
A communication between the three organs
What are the stressors for the HPA axis?
Physical, emotional, or physiological stress stimulates the hypothalamus
What is the function of the hypothalamus?
- Releases Corticotropin-Releasing Hormone (CRH) in response to stress.
- CRH acts on the anterior pituitary gland.
What is the function of the pituitary gland?
- Produces and secretes Adrenocorticotropic Hormone (ACTH) in response to CRH.
- ACTH stimulates the adrenal glands.
What is the function of the adrenal glands?
- Produce cortisol, a glucocorticoid hormone.
- Cortisol is released into the bloodstream and regulates various physiological processes.
How is the HPA axis regulated?
Negative feedback
What is the negative feedback of the HPA axis?
Elevated cortisol levels inhibit CRH and ACTH production through a negative feedback loop. This prevents excessive cortisol release.
What are the manifestations of Cushing’s? (10)
- Decreased growth in children
- Osteoporosis
- Increased appetite
- Glaucoma.
- Increased risk of infections
- Emotional disturbances
- Peripheral edema
- Central distribution of body fat
- Increased risk of diabetes
- Hypokalemia
What are the therapy alternatives for Cushing’s?
Surgical adrenalectomy
Cortisol replacement therapy
What are examples of natural glucocrticoids?
Cortisol
What are examples of synthetic glucocorticoids? (8)
- Cortisone acetate
- Hydroxycortisone
- Prednisone
- Prednisolone
- Methylprednisolone
- Triamcinole
- Dexamethasone
- Betamethasone
What are the different types of glucocorticoid blockers?
- Receptor antagonists
- Synthesis inhibitors
What are the examples of receptor anatgonists?
Glucocorticoid antagonists
Mineralocorticosteroid
What are the examples of glucocorticoid antagonists?
Mifepristone A.
WHat are the examples of mineralocorticosteroids?
Spironolactone
Eplereonone
What are examples of synthesis inhibitors?
Ketoconazole
Aminoglutethimide
Metyrapone
Etomidate
How are cortisone acetate tablets given?
25mg in the morning
12.5mg in the evening
Where are glucocorticoid receptors located? What is the effect of that when it comes to mediaction?
Widely distributed, carefully administered side effects on multiple organs, including the brain!
WHere are mineralocorticoid receptors located?
Receptors are restricted to kidney, colon, salivary glands and sweat glands
And the brain!
What is the effect of short period of cortisol administration?
Cortisol administration, which lasts less than 2 weeks –> no serious effects but insomnia, behavioral changes, and acute peptic ulcers
What are the cellular effects of steroids?
- The steroid present in the blood bound to CBG, binds in free form
- Steroid receptor is associated with heat shock protein HSP90
- Receptor complex H-receptor is formed, HSP0 is released
- H/R enters the nucleus as a dimer binds glucocorticoid-response-elements (GRE) on the gene and regulates transcription factor
- Protein expression
What are the anti-inflammatory effects of glucocorticoids?
They have a suppression effect on inflammatory processes. These drugs increase neutrophils in blood and decrease lymphocytes, eosinophils, basophils, and monocytes
What are the other effects of glucorticoids?
- Glucocrticoids, like cortisol, are required for normal renal excretion of water load.
- They also have effects on the CNS
- Large doses also stimulate gastric acid secretion and decrease resistance to ulcer formation
What is the result of high cortisol levels (renal function)?
Action on the mineralocorticoid receptors (MR)