Thyroid drugs & Others

Question 1

What is the function of thyroid peroxidase?

Answer 1

oxidizes iodide –> iodine

coupling go tyrosine residues

Question 2

How are T3 & T4 formed ?

Answer 2

cleaved from thyroglobulin in follicular cell

T3 is more potent

Question 3

What forms T3 from T4 ?

Answer 3

5’ deiodinase in the peripheral converts T4 to T3

Question 4

What is the relationship between thyroid and catecholamines?

Answer 4

thyroid hormones increases the sensitivity to peripheral tissues to catecholamines by increase beta-adrenergu receptors

Question 5

Radioactive iodine (131-I)

Answer 5

tx : hyperthyroidism in graves

Question 6

What are the side effects of radioactive (131-I)

Answer 6

hypothyroidism
exacerbate graves opthalmopathy
exacerbate hyperthyroidism

Question 7

Propythiouracil

Answer 7

tx: hyperthyroidism by binding directly to TPO
1st trimester & methimazole reaction
inhibit 5 deiodinase –> decrease conversion of T4 to T3

Question 8

What are the side effects of propythiouracil ?

Answer 8

hepatotocity 
liver failure
maculopapular rash 
ANCA- associated vasculitis 
lupus
aplastic anemia 
agranulocytosis

Question 9

Methimazole

Answer 9

hyperthyroidism by inhibiting TPO

Question 10

What are the side effects of methimazole ?

Answer 10

should not be given in the 1st trimester 
agranulocytosis 
lupus 
ANACA- associated vasculitis 
aplastic anemia

Question 11

B- blockers

Answer 11

tx: hyperthyroidism - hypeadrenergic

inhibit 5’ deiodinase conversion T4–>T3

Question 12

Glucorticoids

Answer 12

inhibit 5’ deiodinase that converts T4–> T3

Question 13

Hypothyroidism

Answer 13

decrease BMR , cold intolerance , brittle hair, lethargy

= hashimotos thyroiditis

Question 14

Levothyroxine

Answer 14

tx: hypothyroidism
SE: can cause hyperthyroidism

Question 15

Teriparatide

Answer 15

tx: osteoporosis
increases maturation of osteoblast
increase Ca from the kidney

Question 16

What triggers the release of PTH?

Answer 16

high serum Ca levels

Question 17

What is the function of PTH ?

Answer 17

PTH stimulates osteoblasts to release receptor activator of nuclear factor kappa-B ligand –> activate osteoclasts

RANKL binds to RANK to increase bone reabsorption

PTH increase Ca resorption by the kidney , increase conversion to vitamin D3

Question 18

Teripratide

Answer 18

tx: osteoporosis
stimulate maturation of osteoblasts
increase Ca resorption by the kidney
increase production of 1, 25- dihydroxyvitamin D

Question 19

Calcitrol

Answer 19

stimulates reabsorption of Ca & phosphate by kidney & intestine
stimulates osteoblasts to release RANKL–> increase osteoclast
inhibit PTH
matures osteoblasts

tx: chronic kidney disease
hypoglycaemia

Question 20

Vitamine D

Answer 20

tx: osteoporosis

psoriasis

Question 21

Hypocalcemia

Answer 21

causes parathesisa , muscle cramps, tetany, change in mental status

causes seizures

Question 22

Cinacalet

Answer 22

activates calcium sensing receptor on Parathyroid gland –> decrease production PTH

Question 23

Sevelamer

Answer 23

decrease absorption of phosphate in GI

Question 24

Dexamethasone, fludocortisone, prednisone are ?

Answer 24

glucocorticoids

Question 25

What is the 5 function of glucocorticoids?

Answer 25

GC bind into the cytoplasm --> enter the nucleus and regulates gene transcription inhibit phospholipase A2 in the arachidonic acid --> decrease prostaglandins( COX) & leukotrienes(LOX) inhibit NF-KB --> decrease cytokines--> prevent T & B cells decrease production of neutrophil adhesion molecules reduce peripheral eosinophil counts

Question 26

What are glucocorticoids used to treat?

Answer 26

inflammatory disorders immunosuppressive adrenal insuffiency

Question 27

What are the side effects of glucocorticoids ?

Answer 27

``` insulin resistance--> hyperglycaemia gluconeogenesis increase hepatic glycogen storage proteolysis lipolysis Cushings syndrome central adiposity muscle wasting inhibit fibroblast --> impaired would healing psychosis decreased bone mass ```

Question 28

What is a consequence of exogenous glucocorticoids

Answer 28

adrenal cortical atrophy

Question 29

What does ADH / vasopressin cause?

Answer 29

vascular endothelium to release von Willebrand factor --> increased platelet aggregation

Question 30

Desmopressin acetate treats?

Answer 30

von Willebrand disease hemophilia A esophageal variceal

Question 31

SIADH

Answer 31

overproduction of ADH by ectopic lung cancer, CNS disorders, trauma, some drugs

Question 32

Conivaptan , tolvaptan

Answer 32

tx: SIADH promote free water excretion SE: hypernatremiam central pontine myelinolysis