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Pharm 1 - Corticosteroids Q&As

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isabellepjk's version from 2017-05-06 05:37

Corticos 1

Question Answer
* What is the center of the adrenal gland called and what does it secrete?Called medulla and secretes catecholamines
* What are catecholamines? How are they synthesized?Fight/Flight
NE, Epi, dopamine
Synth by oxidation of tyrosine
What is the outer layer of the adrenal gland called and what does it synthesize?Cortex makes over 30 steroids
*What are the 3 layers of the adrenal cortex & what do they synthesize?OUTER: Zona Glomerulosa (mineralocorticoid synthesis)
MIDDLE: Zona Fascicilata (glucocorticoid synthesis)
INNER: Zona Reticularis (androgen synthesis)
(Deeper = sweeter; GFR; Minerals, Glucose, Androgen (SEX)
* What are the 5 classes of roids?Progestagens
Glucocorts
mineralcorts
androgens
estrogens
* What is the negative feedback mechanism in the hypothalamic-pituitary-adrenal axis?Cortisol exerts a neg feedback on CRH & ACTH release (corticotrophin releasing hormone, corticotrophin)
cortisol in the hypothalamus = DEC CRH
Cortisol in the anterior pituitary = DEC ACTH
*What is the Glucocorticoids and carb metabolism flow chart thing?INC glucocorts = INC gluconeogenesis
= INC Plasma glucose
= INC glycogen synth, insulin release
= Glucose levels back to normal d/t insulin
= DEC insulin = MAY INDUCED DM d/t overworked cells
* Glucocorticoids have what effect on protein metabolism & why?↑ proteolysis leads to ↑ of amino acids, enzyme synth & liver protein & ↑ gluconeogenesis for more sugar for fight or flight
Corticosteriod effect on lipid metab↑ redistribution of fat (possibly due to diff response to insulin & glucocorticoids by truncal & peripheral fat) & ↑ action of lipolytic hormones such as growth hormones & beta-adrenergic receptor agonists
* Corticosteroid effect on lytes and water balance?PUPD d/t decrease vasopressin
Inc GFR and Na and water excretion d/t inc CVS fx
DEC GIT absorption and renal absorption of Ca, which leads to decrease plasma Ca so then PTH is secreted which increases bone resorption, and decreases osteoblasts which leads to a decrease in bone formation
* What three things do mineralocorticoids cause?INC Na absorption/resorption in Kidneys and LI
DEC K, H, and Cl retention in kidneys
saves water
* What is the effect of glucocorticoids on the feeling of well-being?↑ of euphoria & excitation, appetite improves, a ↓ will lead to depression
* General effects of MCs and GCs include?INC vasomotor responses and myocardial contractions
* Mineralocorticoids effects on the CV system have what influence on the Ca++ levels in the myocardium?MCs ↑ Na in the ECF, which leads to ↑ BP
that leads to ↓ K in ECF (which leads to ↑ Ca++ in myocardium)
Glucocorticoid effects on the CV system include BV constriction & ↑ in heart rate, contractibility & CO. Why is this?This is due to an ↑ in Epi formation which will lead to an ↑ in alpha-adrenergic receptors (BV constriction) & an ↑ in beta-1-adrenergic receptors (↑ HR, contractility, & CO). ALSO ↑ in angiotensinogen productions (↑ ACE & angiotensin II = ↑ BP)
* What are the GCs effect on the resp system?Bronchodilation d/t INC ib b2 adrenergic receptors
ANTIinflamm d/t DEC in mast cell retention which = DEC histamine release
What is the effect of corticosteriods on sk mm? (Needed to maintain mm fx) Def leads to mm weakness d/t hypoglycemia and poor circulation
* What are the effects of INC mineralocorticoids in skeletal mm?↑ mineralocorticoid levels lead to hypokalemia & mm weakness
* What are the effects of glucocorticoids in skeletal mm?↑ levels over a long time lead to mm weakness due to wasting of mm (from proteolysis)
* What are the effects of GCs on blood?INC RBCs, Platelets, and Neuts
DEC Lymphos, Eos, Monos, Basos
GCs DEC interleukin release, what is the result of the DEC in IL1 production and the production of IL2 from T cells?IL1 DEC = DEC b cell and IgG production, T cll activation, phagocytosis
IL2 production also DEC b cell prolif and activation of T cells
ALSO increases lymph apoptosis
What is the effect of GCs on lymphoid tissue?DEC size of lymph nodes and thymus
What are the 4 general actions of GCs?Immunological, Cancer, Anti inflam, Healing
What are 4 ways glucocorticoids have anti-inflammatory actions?(1) ↓ IL-8, the chemo-attractive factor/adhesion factor(results in ↓ migration of WBC to area of inflammation)
(2) ↓ PLA2 or ↓ arachidonate formation from cell membrane breakdown
(3) ↓ Autocoids-like histamine, from mast cells
(4) ↓ Proteolytic enzymes
* How is skin/hair growth effected by glucocorticoids?↓ skin & hair growth (alopecia)
memorize

Corticos 2

Question Answer
* The structure of corticoids steroids impart which 2 characteristics?GC action and DoA
* What are the 4 variables which influence the duration of action of glucocorticoids?(1) % of drug bound to plasma proteins (↑ pp is ↑ duration, as only ther free steroids and able to be metabolized and eliminated)
(2) Affinity the drug has for the enzymes involved in their metabolism (↓ affinity is longer duration)
(3) Lipophilicity of the drug (↑ lipophilic is ↑ duration)
(4) Affinity the drug has for the glucocorticoid receptor (↑ affinity ↑ duration)
What are the 2 short acting CSs?Hydrocortisone (Cortef) and Hydrocortidone Na Succinate (Solu-Cortef)
What are the 4 intermediate acting corticosteroids?Prednisolone and Prednisone
methyl-Prednisolon
Triamcinolone Acetonide
Fludrocortisone Acetate
*What are some important features of Prenisolone and Prednisone?5x more potent antiimflam than cortisole and 0.8% MC compared to cortisol
Horses and Cats PREDNISOLONE ONLY; they're not good at converting prednisone to prednisolone
What are common uses of Prednisolone and prednisone?Hypoadrenocorticism
Anti-inflam
immunosuppressive
Antineoplastics
Which of the three forms of MethyPred should be used carefully in cats and why?Methyl Prednisolone Acetate because Cats may have undesired prolonged HPA axis suppression
Which CCs can be given IM?Methyl-Prednisolone Acetate (Depo-Medrol)
What is important to note about Methy-Predinosolon (interm acting)5x more potent GC action than hydrocortisone
What is true about MOST Preds ?5x more important GC or antiinflam action than hydrocortisol
What is important about Triamcinolone acetonide (Vetalog)?30x more potent GC action than hydrocort
no min MC effect
What is Triamcinolone acetonide (Vetalog) labeled for?anti-inflam in dogs, cats, and horses
acute arthritis, allergic, and derm disorders
What is important about the action of Fludrocortisone Acetate?10x more potent GC and 125x more potent MC effect
For what can Fluddrocortisone acetate be used in small animals?Addison's and hyperkalemia
What are important characteristics of Flumethasone (Flucort)? Which animals is in used in a for what? 120x more potent GC; no MC effect
Horses: MSK inflam and allergiex rxns
Dogs: MSK inflamm, Allergic states, Derm, shock
Cats: Derm
What are important characteristics of Betamethasone?25x more potent GC, no MC effect
used in combo with others for topical admin
For what can dexmethasone be used in cattle?Abortion
For what is Desoxycorticosterone Pivalate (DOCP) used long term in small animals?Addison's
What two drugs are noted for tx of addisons?Fludrocortisone Acetate and DOCP (desoxycorticosterone Pivalate)
DOCP for long term
How should water soluble corticosteroids be administered?IV
How should water insoluble corticosteroids be administered?IM and SC
How are most GCs metabolised and eliminated?conjugation in the liver and elimination via kidneys
*How do you make sure the HPA axis can return to normal function when stopping steroid therapy in addisons?TAPERING THE DOSE
Occurs when GC admin is stopped abruptly and ACTH secretion has feedback inhibition
*What are important side effects of Corticosteroids?INC chances of infection/DEC would healing
GIT ulceration and DM
Myopathy
hepatotox
Abortion
laminitis in horses
Edema
*When should you NOT used GCs?With corneal ulcers, burns, DM, uncontrolled infections, Cardiac disorders, Late preg
What are the 2 categories of cushings (HYPERadrenocorticism)? Which is more dominant?Pit dependent-PDH
Adrenal dependent
85% of dogs have PDH
*What are some of the Adrenal steroid inhibitors?Mitotane, Ketoconazole, Selegiline, Trilostane
What are important features of the adrenal steroid inhibitor mitotane?Destroys ZF and ZR cells, can result in heptotox, and can cause HYPOadren (addison's)
*What are important features of the adrenal steroid inhibitor Ketoconazole?Used when mitotane isn't effective
Reversibly blocks Cp450
GI and repro side effects and heptotox
*What are important features of the adrenal steroid inhibitor Selegiline (Anipryl, Eldepryl)Cushings and dementia tx
MAO B inhibitor and inhibits ACTH secretion
What are important features of the adrenal steroid inhibitor Trilostane?Safer than Mito and Ketocon
Decreases synth of cortisol, aldos, and androgens
rare side effect = adrenal gland necrosis and addison's dz
inhibitor or 3-beta hydroxysteroid dehydrogenase
*Which species most often get Addisons?Young, adult female dogs
occasionally in horses
*What is the Na:K ratio in Addisons?HYPONat, HYPERKal = Na:K= <25:1
Wahat are the signs of Addison's?Hypotension, dehydra, bradycardia, renal failure, circ collapse, v+/d+, anorexia, hypoglycemia, hyperpigmentation
* Which layers of adrenal gland are affected in Addisions?ALL THREE
*What is the Addisonian Crisis TxIV fluids with Dextrose added, Predi Na succinate OR dexmethasone Na phosphate to overcome shock
*What is the general maintenance therapy for Addisions?Pred/Prenisolone and mineralcort replacement
Monitor with SERUM electrolytes every three months
* What moieties indicate a drug should be given IV as it is water soluble Succinate, Phosphate, Polyethylene glycol
*Why does trilostane reduce the synthesis or cortisol, aldosterone, and androgens?It is a competitive inhibitor of 3-beta hydroxysteroid dehydrogenase
memorize