B-19/20. Glucocorticoids for oral and parenteral use. Topically applied glucocorticoids and Mineralocorticoids. Flashcards
Which interleukins upregulate the hypothalamus and anterior pituitary?
Which neurotransmitters upregulate the hypothalamus?
Which neurotransmitters/hormone downregulates the hypothalamus (CRH neurons)?
- ) Il-1, Il-2, Il-6, and TNF-alpha upregulate (they are released from the immune system via the lymphocytes, macrophages, monocytes, and neutrophils)
- ) Ach, 5-HT, NE upregulate
- ) NE, GABA, and cortisol downregulate
What hormones upregulate/downregulate the anterior pituitary (Corticotropes)?
CRH upregulates the anterior pituitary and cortisol downregulates it
What hormones upregulate the adrenal cortex (fasciculata cells) and why do we measure it?
ACTH upregulates the adrenal cortex leading to the release of cortisol.
It is measured for diagnostic purposes and certain epilepsies in childhood.
What do the different cells in the adrenal cortex get upregulated by, release, and via which CYP enzyme?
- ) Zona Glomerulosa?
- ) Zona Fasciculata?
- ) Zona Reticularis?
- ) Zona Glomerulosa
- Upregulated by Angiotensin II/K+ releasing aldosterone via CYP11B2 - ) Zona Fasciculata
- Upregulated by ACTH releasing cortisol via CYP11B1/CYP17 - ) Zona Reticularis
- Upregulated by ACTH releasing DHEA via CYP17
What are the genomic and non-genomic mechanisms of steroid hormone operation?
The steroid hormones (aldosteron, cortisol, progesterone, estrogen, and testosterone) act via the…
- ) Genomic action where the hormone crosses the lipid membrane and binds an intracellular receptor, transducer, and messenger to bind directly to DNA to amplify and undergo gene transcription
- ) Nongenomic action which binds a receptor on the cell surface that activates a tranducer (Alpha, beta + gamma subunits) which upregulate amplifiers that create messengers that have intracellular effect (AC creates cyclic AMP, PI 3-k creates PIP3, and PLC creates DAG and InsP3 which increases intracellular calcium)
What are some specific gene transcriptions can the steroid-glucocorticoid receptor complex activate?
It interacts with other transciptions factors like NF-kB and AP1 which are involved in anti-inflammatory and immunosuppressive effects
Glucocorticoid receptor actions (Gene activation)
- ) Annexin-1 which decreases PLA2 (precursor for eicosanoids, such as prostaglandins and leukotrienes.)
- Eicosanoids function in diverse physiological systems and pathological processes such as: mounting or inhibiting inflammation, allergy, fever and other immune responses; regulating the abortion of pregnancy and normal childbirth; contributing to the perception of pain; regulating cell growth; controlling blood pressure; and modulating the regional flow of blood to tissues. - ) Enzymes of gluconeogenesis and amino acid metabolism (cAMP dependent protein kinase)
- ) Adrenergic receptors on vascular and bronchial smooth muscle (permissive effect e.g. B2 agonist effect in bronchial asthma)
Glucocorticoid receptor actions (Gene repression)
COX-2, NOS, Cytokines, Interleukins, and Cell adhesion molecules
* 10-20% of expressed genes are regulated by glucocorticoids
Glucocorticoid metabolic effects
- ) Carbohydrates?
- ) Proteins?
- ) Lipids?
1.) Carbohydrates
-Decreased glucose uptake and utilization
-Increased gluconeogenesis
(Hyperglycemic tendency)
2.) Proteins
-Increased catabolism
-Decreased anabolism
3.) Lipids
-Redistribution of fat (Cushing type)
-Increased triglycerides
-Increased LDL/HDL
Glucocorticoid regulatory effects part 1:
- ) Hypothalamus and anterior pituitary gland?
- ) Cardiovascular system?
- ) Musculoskeletal?
- ) Hypothalamus and anterior pituitary gland
- Negative feedback causes decreased release of endogenous glucocorticoids - ) Cardiovascular system
- Decreased vasodilation - ) Musculoskeletal
- Activity of osteoblast decreased and osteoclast activity increases (less bone formation)
Glucocorticoid regulatory effects part 2:
Inflammation and immunity?
- ) Less influx and activity of leukocytes in acute inflammation
- ) Less activity of mononuclear cells, angiogenesis, and fibrosis in chronic inflammation
- ) In the blood there will be more neutrophils and less eosinophils, basophils, monocytes, and lymphocytes
- ) Lymphoid tissues will have decreased T/B cells clonal expansion and decreased cytokine secreting T action
Glucocorticoid regulatory effects part 3:
Mediators?
Overall effects?
1.) Decreased production and action of cytokines (ILs, TNF-alpha, GM-CSF)
2.) Less generation of eicosanoids
3.) Less generation of IgG
4.) Decreased complement components in the blood
5.) Increased release of anti-inflammatory factors (e.g. IL-10 and annexin-1)
Overall effects: activity of the innate and acquired immune systems decrease as well as healing and protective aspects of inflammation
Clinical uses of glucocorticoids (6)
- ) Replacement therapy (adrenocortical insufficiency, Addison’s disease)
- ) Diagnostic purposes (dexamethasone suppression test, Cushing’s syndrome, diff. diagnosis of depression)
- ) Stimulation of lung maturation in fetus (premature before week 34)
- )Anti-inflammatory/immunosupressive therapy (more in next flashcard)
- ) In neoplastic diseases (more in next flashcard)
- ) Nausea and vomiting (in chemotherapy and general anesthesia)
Glucocorticoid Anti-inflammatory/immunosupressive therapeutical uses (5)
- ) In asthma
- ) Topically in inflammatory conditions of skin, eye, ear, nose (e.g. eczema, allergic conjunctivitis or rhinitis)
- ) Hypersensitivity states (e.g. severe allergic rxn)
- ) In diseases with autoimmune and inflammatory components (e.g. RA and other connective tissue diseases, IBD, some forms of haemolytic anaemia, idiopathic thrombocytopenic purpura)
- ) To prevent graft vs host rxn (organ or bone marrow transplantation
Glucocorticoid neoplastic diseases therapeutic uses (2)
- ) In combination with cytotoxic drugs (Hodgkin’s disease, acute lymphocytic leukaemia)
- ) to reduce cerebral oedema (metastatic or primary brain tumours; dexamethasone)
Glucocorticoid drugs (11)
- ) Hydrocortisone (Cortisol)
- ) Cortisone
- ) Deflazacort
- ) Prednisolone
- ) Prednisone
- ) Methylprednisolone
- ) Triamcinolone
- ) Dexamethason
- ) Betamethasone
- ) Fludrocortisone
- ) Aldosteron
Which glucocorticoid drugs are prodrugs
Cortisone, Prednisone, Deflazacort, and Fludrocortisone
Glucocorticoids of short action (8-12 hours)
Hydrocortisone, Cortisone, and Deflazacort
Glucocorticoids of intermediate action (12-36 hours)
Prednisolone, Prednisone, Methylprednisolone, Triamcinolone
Glucocorticoids of long action (36-72 hours)
Dexamethasone and Betamethasone
Strongest anti-inflammatory Glucocorticoids (3)
Dexamethasone, Betamethasone, and Fludrocortisone
Which 2 glucocorticoids have minimal sodium retaining ability
Dexamethasone and Betamethasone
Which 2 glucocorticoids have high sodium retaining ability
Fludrocortisone and Aldosterone (endogenous mineralocorticoid)
Hydrocortisone function
Drug of choice for replacement therapy
Cortisone function
Cheap, inactive until converted to hydrocortisone
Deflazacort function
Must be converted by plastma esterases into active metabolite, similar utility to prednisolone
Prednisolone function
Drug of choice for systemic anti-inflammatory and immunosuppressive effect
Prednisone function
Inactive until converted to prednisolone
Methylprednisolone function
Anti-inflammatory and immunosuppresive
Dexamethasone function
- ) Anti inflammatory
- ) Immunosuppressive, used especially where water retention is undesirable (e.g. cerebral edema)
- ) Drug of choice for suppression of adrenocorticotrophic hormone production
Bethamethasone function
Anti-inflammatory and immunosuppresion (used especially when water retention is undesirable)
Fludrocortisone function
Drug of choice for mineralocorticoid effects
Aldosterone function
Endogenous mineralocorticoid
Cortisol is deactived to cortisone by which enzyme? Activated by which enzyme?
Cortisol is deactivated by 11B-HSD2. Activated 11B-HSD1.
Topical administration of glucocorticoids (7) and advantage of topical administration
Advantage of topical administration, decreased systemic side effects
- ) Bronchial asthma: aersol
- ) Allergic rhinitis: nasal spray
- ) Ophthalmology: Optical Glucocorticoid Therapy
- ) Dermatology: ointment, solution
- ) IBD: suppository, enema
- ) Joint disease: intra-articular
- ) Timed-release tablet (physiology-like cortisol levels; high morning, low evening)
Glucocorticoids meds used for bronchial asthma aerosol
beclomethasone, fluticasone, mometasone, budesonide, flunisolide
Glucocorticoids meds used for allergic rhinitis nasal spray
beclomethasone, triamcinolone, budesonide, flunisolide
Glucocorticoids meds used for dermatology
Flumetazone, triamcinolone, fluocinolone w/ acetonide moiety w/ increased topical activity
Pharmacokinetics of glucocorticoids Oral absorption? Transport in blood? Half life? Metabolism?
- ) Good p.o. absorption
- ) Transport in blood by
- 90% corticosteroid-binding globulin (CBG)/a2 globulin
- 5-10% free
- 5% albumin (large capacity, low affinity practically considered as free) - ) 60-90 minute half life
- ) Metabolism
- 80% in the liver
- 20% in the kidney and other MR containing tissue (e.g. colon, salivary glands)
- 1% unchanged in the urine
Unwanted unusual serious side effects
- ) insomnia, hypomania
- ) peptic ulcer
- ) acute pancreatitis (rare; only at high dose)
Unwanted effects of glucocorticoids (longer than 2 week therapy) (11)
- ) Response to infection or injury decreased (wound healing decrease, peptic ulceration, oral candidiasis)
- ) Iatrogenic Cushing’s syndrome
- ) Suppression of endogenous glucocorticoid synthesis
- ) Hypokalemia, hypernatremia, edema, hypertension
- ) Osteoporosis
- ) Aseptic necrosis of femoral head
- ) Hyperglycaemia, insulin increased, weight game, DM
- ) Muscle wasting, myopathy
- ) Inhibition of growth in children (if> 6 months treatment)
- ) CNS effects: hypomania, psyhosis (at very large doses), long term: depression
- ) Other effects: glaucoma (in genetically predisposed persons), incidence of cataracts increased, intracranial pressure increased
What type of diet should patients be on if they are on long term glucocorticoid therapy
High protein and K+ enriched diet
What is the 2 essential dosage rules of glucocorticoids
Driven by seriousness of the disease, duration of therapy.
Keep dosage as low as possible-titrate!
Dosage in these cases
- ) initial doses?
- ) To supress ACTH?
- ) Inflammatory and allergic disorders?
4) Severe autoimmune disease? - ) If large dose required?
- ) If large dose for long period required?
- ) If large dose is required?
- ) How to stop treatment?
Dosage in these cases
1.) initial doses
-Higher doses for initial effect, lower dose for maintanence
2.) To suppress ACTH
-Small, frequent p.o. doses or slowly absorbed p.e. preparation
3.) Inflammatory and allergic disorders
-Same quantity in a few doses
4) Severe autoimmune disease
-High, divided dose, gradual reduction later on
5.) If large dose required
Synthetic with minimal mineralocorticoid action
6.) If large dose for long period required
-Try alternate-day administration (side effects decreased sometimes)
7.) If large dose is required
-Medium or intermediate-acting synthetic steroid with little MR action
8.) How to stop treatment
-Slow, gradual cessation, otherwise disease symptoms may reappear or even intensify
Mineralocorticoid receptor actions
Genomic? Non-genomic?
Genomic
-Na+/K+-ATPase transcription increases
-ENa channel activity increases (Increased Na+ reabsorption and K+ and H+ excretion increased in the collecting tubule and duct)
-Increased expression of profibrotic molecules (e.g. TGF-B)
-Increased NADPH oxidase expression, ROS (proinflammatory effect)
Non-genomic
-Proinflammatory effects (via EGFR and ERK1/ERK2)
Clinical uses of mineralocorticoids
Replacement therapy in adrenal hypofunction (fludrocortisone) and Chrousos syndreome (genetic: GR inactivation); high dose of synthetic glucocorticoid w/o inherent MR activity
Clinical uses of mineralocorticoid antagonist
- ) Spironolactone: K+ sparing diuretic (also an androgen and progesterone receptor antagonist), preimary aldosteronism (adrenal adenoma)
- ) Eplereone: hypertension, heart failure
Unwanted effects of the mineralocorticoids (4)
- ) Edema
- ) Increased blood pressure
- ) Hypokalemia (weakness, tetany), metabolic alkalosis
- ) Pro-inflammatory effect
Adrenocortical antagonists
- ) Metyrapone
- ) Mitotane
- ) Ketoconazole
- ) Aminogluthetimide
- ) Etomidate
- ) Trilostane
- ) Mifepristone
Metyrapone MOA and function
Inhibitor of 11 B-hydroxylase for diagnostic purposes
Mitotane
Derivative of?
Taken?
Function?
- Derivative of insecticide DDT
- p.o.
- Used in adrenal carcinoma (cytotoxic for adrenal cortex decreases tumor mass; fairly toxic)
Ketoconazole MOA and function
- Inhibits cholesterol to pregnenolone and 17-alpha-OH
- Antifungal drug used in Cushing syndrome
Aminogluthetimide function (2)
- ) In conjunction with ketoconazole or metyrapone in Cushing syndrome due to adrenocortical cancer not responding to mitotane
- ) In conjunction with dexamethasone or hydrocortisone to reduce estrogen in breast cancer
Etomidate MOA and function
- Inhibitor of 11 B-hydroxylase, I.V. anesthetic
- In severe Cushing syndrome
Trilostane function
comparable to aminogluthetimide
Mifepristone (SPRM) function
“Chemical abortion” with antiprogesteron and antiglucocorticoid activity for inoperable ectopic ACTH tumors or adrenal carcinoma