endocrine Flashcards
(90 cards)
HPA axis diagrammed
Adrenal Gland
Comprised of adrenal cortex and adrenal medulla
◦ Inner – medulla
secretes catecholamines
◦ Outer – cortex
secretes adrenal steroids
Adrenal cortex produces about 50 different chemicals
adrenal products with pharmacologic properties:
Mineralocorticoids
Glucocorticoids, cortisol
Androgens
Adrenal Cortex layers
3 layers within cortex
◦ zona glomerulosa: produces mineralocorticoids
◦ zona fasciculata produces glucocorticoids
◦ zona reticularis: produces sex hormones, mostly androgens and small amount of glucocorticoid
Mineralocorticoids function
(produced in zona glomerulosa)
Regulate water and electrolyte balance
◦ Sodium (Na +), Potassium (K+) and fluid balance
◦ Provide important homeostatic functions
main mineralcorticoid and its function
Aldosterone – main endogenous hormone
◦ essential for blood pressure regulation and electrolyte and fluid homeostasis - helps to maintain normal blood pressure and electrolyte balance
◦ acts on the Mineralocorticoid Receptor (MR
Mineralocorticoid Receptor roles:
MR renal
Extra-renal MR plays a relevant role in?
Overactivation of the MR is implicated in?
MR present in kidneys impacts fluid and electrolyte balance
Extra-renal MR plays a relevant role in the control of cardiovascular and metabolic functions
Overactivation of the MR is implicated in the pathophysiology of aging related to cardiovascular, metabolic and kidney dysfunction and progress of diseas
Aldosterone Basics
Aldosterone Basics
Increases Na+ reabsorption by distal tubules in kidney
with concomitant increased excretion of K + and H +
Increases BP and blood volume – balance/control the
amount of sodium and fluids in the body
Work on specific intercellular receptors in kidney
Pharmacotherapeutic use of medications involving
mineralocorticoid effects
Replacement therapy Addison’s Disease/Adrenal Insufficiency
◦ Addison’s Disease (autoimmune disease)/Adrenal Insufficiency –
adrenal do not produce enough of the steroid hormones, cortisol
and aldosterone
Fludrocortisone (Florinef)
class?
Functionally similar to?
Most effect of all available roids?
Other steroids have much smaller amounts of? or no?
Other indications:
mineralocorticoid
Functionally similar to aldosterone
Most mineralocorticoid effect of available steroids
Other steroids have much smaller amounts of mineralocorticoid effects
(example: hydrocortisone, prednisone) or no mineralocorticoid effects
(example: dexamethasone, methylprednisolone)
Other indications: orthostatic hypotension, septic shock
Drugs that Inhibit Aldosterone:
imbalances of aldo and its results?
Imbalances in aldosterone and overactivity of the mineralocorticoid receptor contribute to hypertension, kidney insufficiency, heart failure and potentially other cardiovascular disease
◦ Due to idiopathic adrenal hyperactivity (most common) or benign tumor (Conn’s
syndrome)
Spironolactone (Aldactone) and Eplerenone (Inspra)
with steroidal structure
competitive aldosterone antagonist at receptor sites in distal renal tubules (block higher
concentration of kidney-specific MR), increasing sodium chloride and water excretion while conserving potassium and hydrogen ions – prevents mineralocorticoid effects of adrenal steroids on the renal tubule
Steroidal structure
Also known as a potassium sparing diuretics
Spironolactone (Aldactone) and Eplerenone (Inspra) indications
Hyperaldosteronism (secondary cause of hypertension and causes low potassium)
Heart failure
Hypertension
Drugs that Inhibit Aldosterone (Non-steroidal)
Finerenone (Kerendia)
Finerenone moa
◦ Blocks Mineralocorticoid receptor (MR) in kidney and heart
◦ Selectively blocks (antagonist) mineralocorticoid receptor-mediated sodium reabsorption and overactivation of kidney, blood vessel, and heart tissues, reducing fibrosis and inflammation
◦ MR overactivation is an important factor associated with CV events and Chronic Kidney Disease (CKD) progression (similar to SGLT2 inhib)
Glucocorticoids:
(endogenously produced in?
Mechanism of action –
* Widespread actions on?
* Potent regulatory effects on?
◦ Glucocorticoid receptors up regulate expression of? and down regulate expression of?
(endogenously produced in zona fasciculata)
Mechanism of action – complex: work through specific glucocorticoid intracellular receptors to regulate several vital cell activities
◦ Metabolic
◦ Immune function
* Widespread actions on intermediate metabolism, affecting carbohydrate (glucose), protein and fat metabolism
* Potent regulatory effects on host defense mechanisms including inflammation and immune function
◦ Glucocorticoid receptors up regulate expression of anti- inflammatory proteins and down regulate expression of pro- inflammatory proteins
main endogenous hormone of humans
Main endogenous hormone in humans – hydrocortisone
(also called cortisol)
◦ Produce 24-30 mg endogenous hydrocortisone/cortisol
◦ Use up to 300 mg/day in times of significant stress
how is cortisol secreted/when is it highest?
circadian rhythm, highest early in morning
HPA axis pathway
◦ Hypothalamus releases Corticotrophin-Releasing Hormone [CRH]
◦ Adrenocorticotropic hormone [ACTH] released from the anterior Pituitary
◦ Adrenals release glucocorticoids
◦ Negative feedback mechanism to inhibit CRH and ACTH when glucocorticoid concentrations increase in the blood
Therapeutic Use of Corticosteroids
- Many have partial mineralocorticoid and glucocorticoid properties
- Most are used for anti-inflammatory and immunosuppressive properties
common indications of corticosteroids
◦ Addison’s disease/Adrenal Insufficiency
◦ Cancer therapy (reduce ADE)
◦ Anaphylaxis
◦ Hypersensitivity states
◦ Shock
◦ Autoimmune disease
◦ Asthma (inhaled)
◦ Chronic obstructive pulmonary disease
◦ Respiratory distress syndrome in infants
◦ Suppressing rejection
◦ Acute renal insufficiency
◦ Inflammatory conditions of eyes, ears, nose or skin /rashes of the skin
Use of Steroids in Dentistry
Use for anti-inflammatory, pain management and auto-immune properties
Oral lesions
◦ Aphthous ulcers/stomatitis
◦ Oral lichen planus
◦ Erythema multiforme
◦ Behcet’s disease
◦ Pemphigus
◦ Bullous pemphigoid
◦ Systemic lupus erythematosus
Restorative dentistry/pain management
Bell’s palsy
Post herpetic neuralgia
Temporomandibular joint disorder
Temporal arteritis
Formulations of Corticosteroids for dentistry (topical)
◦ Importance of ?
◦ Example of commercially available product:
Dental (topical oral) applications
◦ Pastes, ointments/orabase, gels, lozenges, intralesional therapy, rinses – commercially
available or compounded
◦ Importance of contact time with lesion
◦ Example of commercially available product:
Kenalog® in Orabase® / Triamcinolone Dental Paste
pt education for corticosteroids used in dentistry
- Using a cotton swab, press (do not rub) a small amount of paste onto the area to be treated until the paste sticks and a smooth, slippery film forms. Do not try to spread the medicine because it will become crumbly and gritty.
- (Usually applied 2-3 times per day – see dosing information of the product). Apply the paste at bedtime so the medicine can work overnight. The other applications of the paste should be made following meals.