Endocrine Disorders

Question 1

Thyroid gland active hormones (2)

Answer 1

Triiodothyronine (T3)
Thyroxine (T4)

Question 2

Actions of thyroid hormones

Answer 2

1. stimulation of energy use -> calorigenic
2. stimulation of heart: increase HR, increase blood flow
3. promote growth and development

Question 3

Levothyroxine

Answer 3

[synthroid, many brands]
synthetic prep of T4
- converted to T3
- highly protein bound -> t1/2 = 7 days

Question 4

Liothyronine

Answer 4

[Cytomel]
synthetic prep of T3
- more ptoent but shortr t1/2
- higher cost
- increased dcardiotoxicity

Question 5

Thyroid hormones AE

Answer 5

with significant overdosage -> thyrotoxicosis
- tachycardia, tremors, nervousness, insomnia

BBW: ineffective and potentially dangerous for treatment of obesity/weight loss in euthyroid patients -> life-threatening toxic effects

Question 6

Methimazole [Tapazole]

Answer 6

uses: hyperthyroidism
MOA: suppression of thyroid hormone synthesis
- longer t1/2 -> once daily with preferred side effect profile

Question 7

Propylthiouracil (PTU)

Answer 7

uses: hyperthyroidism
MOA: suppression of thyroid hormone synthesis
- short t1/2 -> needs to be administered several times/day

Question 8

Beta blockers (3) -ol

Answer 8

Propranolol
metoprolol
atenolol

uses: hyperthyroidism
MOA: suppress tachycardia and other symptoms

Question 9

Radioactive iodine [I131]

Answer 9

uses: hyperthyroidism
MOA: destroy thyroid tissue in patients with hyperthyroidism
- safe and effective but hypothyroidism occurs 80%
- 1st choice in elderly and post menopause with persistent nodules

Question 10

Non-radioactive iodine [lugol’s solution]

Answer 10

uses: hyperthyroidism
MOA: at high concentrations, iodide has a suppressant effect on the thyroid

Question 11

Hormones of anterior pituitary (6)`

Answer 11

growth hormone (GH)
follicle-stimulation hormone (FSH)
luteinizing hormone (LH)
thyrotropin (TSH)
prolactin
corticotropin, adrenocorticotropic hormone (ACTH)

Question 12

Hormones of the posterior pituitary (2)

Answer 12

oxytocin
antidiuretic hormone

Question 13

Growth hormone aka somatropin [Saizen]

Answer 13

Biologic effects:
- Promotes growth, protein synthesis, and carbohydrate metabolism

Therapeutic uses: IM or SubQ
- Pediatric GH deficiency
- Pediatric non-GH deficient (NGHD) short stature
- Adult GH deficiency → increases lean body mass

Question 14

Growth hormone aka somatropin [Saizen] abuse

Answer 14

Abuse → DOPING w/hGH has become an increasing problem in sports during the last 15yrs

Question 15

Prolactin

Answer 15

produced by the anterior pituitary
- stimulation of milk production after parturition

Question 16

Cabergoline [Dostinex]

Answer 16

a dopamine agonist
- for suppression of prolactin release

Question 17

Oxytocin

Answer 17

• promotes uterine contractions during labor
• stimulates milk ejection during breast feeding

• induction of labor near term

Question 18

Antidiuretic hormone (ADH) aka vasopression

Answer 18

ADH promotes renal conservation of water

Desmopressin: diabetes insipidus, primary nocturnal enuresis (bedwetting, urination while sleeping)
vasopressin: vasopressor- shock

Question 19

Adrenocorticol hormones (steroid hormones) (3)

Answer 19

glucocorticoids (cortisol)
mineralocorticoids (aldosterone)
androgens (androstenedione)

Question 20

Glucocorticoids uses

Answer 20

1. Adrenocortical insufficiency → Addison’s disease
2. Non-adrenal disorders

Question 21

Nonadrenal disorders

Answer 21

• Allergic conditions
• Asthma
• Dermatologic disorders (eczema, psoriasis)
• Miscellaneous inflammatory disorders (e.g., tendinitis, bursitis, osteoarthritis, gouty arthritis)
• CA arising from lymphoid tissues (leukemia, Hodgkin’s disease) in conjunction w/antiCA drugs
• Suppression of allograft rejection in conjunction w/other immunosuppressive agents
• Autoimmune diseases: RA, systemic lupus erythematosus (SLE)
• Inflammatory bowel disease

Question 22

Steroid receptor complex

Answer 22

MOA: glucocorticoids binds to intranucler receptors -> complex activates transcription of certain genes

Question 23

Corticosteroid Clinical Considerations

Answer 23

• Therapeutic use, usually empirical
• Nonspecific and palliative, not curative
• Adrenal suppression by negative feedback regulation during long term therapy.
• Avoid abrupt cessation -> Glucocorticoid withdrawal should be done slowly when given for > one month
• Intermittent dosage used when possible
• Use smallest dose for desired effect
• Administered before 9:00 AM to avoid adrenal insufficiency and mimic the burst of endogenous release
• During long term therapy, higher dose should be given at time of stress

Question 24

Glucocorticoid withdrawal

Answer 24

• Depend on signs of adrenal suppression
• Taper the dosage to physiologic range over 7 days
• Taper the dosage to 50% of physiological values over the next months
• Switch from multiple Doses to single dose
• Monitor for production of endogenous cortisol -> cease replacement therapy when basal levels return to normal

Question 25

Glucocorticoids AE

Answer 25

Adrenal insufficiency Susceptibility to infection Osteoporosis Hyperglycemia and glucosuria Weight gain Fluid and electrolyte disturbance, edema, hypokalemia Cataracts and glaucoma Peptic ulcers by inhibiting PG synthesis Growth retardation in children CNS effects, nervousness, insomnia, depression, euphoria Cushing syndrome

Question 26

Hydrocortisone [Cortef]

Answer 26

short to medium acting/low GC potency

Question 27

Prednisone [Deltasone]

Answer 27

For oral anti-inflammatory and immunosuppressant - prednisone is a prodrug → chemically changes in body after it is swallowed → turns into active form, prednisolone*

Question 28

Methylprednisone [Medrol]

Answer 28

PO: more potent than prednisone

Question 29

Dexamethasone [Dex Pax]

Answer 29

long acting GC/potent GC - potent anti-inflammatory

Question 30

9- alphafludrocortisone [Florinef]

Answer 30

MOA: binds to aldosterone receptor -> mineralocorticoid property and glucocorticoid activity uses: addison's disease, adrenogenital disorder AE: edema, hyperglycemia decrease body growth

Question 31

Mifepristone [Korlyn]

Answer 31

MOA: cortisol receptor blocker at high dose, at low dose it is a progesterone receptor blockers -> inhibition of progesterone during pregnancy, causing expulsion of product of conception through contraction uses: tx for hyperglycemia secodary to hypercortisolism -mifepristone + misoprostol -> abortion < 40 days of pregnancy AE: abnormal bleeding, HTN, edema