GH antagonist and agonists

Question 1

which gland releases GH?

Answer 1

anterior pituitary

Question 2

which hormones released by hypothalamus control GH?

Answer 2

growth hormone releasing hormone GHRH

GH inhibiting releasing hormone GHIH

Question 3

what is the other regulatory effect of somatostatin?

Answer 3

somatostatin which is GHIH :

inhibit GH

ALSO INHIBIT TSH

Question 4

what would do the effect of inhibiting TSH result in terms pharmacodynamics?

Answer 4

it will lead to hypothyrodism due to TSH suppression

Question 5

how is GH administered ?

Answer 5

Always as injection cannot be given orally

Question 6

What is recombinant somatotropin ? rhGH?

Answer 6

biosynthetic form of human growth hormone

given to patients with GH deficiency

Question 7

in cause of dwarfism, how often is somatotropin administered ?

Answer 7

subcutaneously ONCE DAILY

Question 8

what are examples of somatostatin administered ?

Answer 8

Somapacitan

Lonapegsomatropin

Somatrogon

all given once weekly and long acting

Question 9

describe somapacitan?

Answer 9

Long acting rhGH analog

given to children 2.5 years old and OLDER

CANT BE GIVEN FOR KIDS YOUNGER THAN 2.5 YEARS OLD

GIVEN ONCE WEEKLY

Question 10

describe lonapegsomatropin ?

Answer 10

sustained release preparation of rhGH

given to children 1 year of age and older

cant be given to children less than 1 years old

prodrug of somatropin

once weekly

Question 11

describe somatrogon ?

Answer 11

long acting rhGH analong

once weekly

Question 12

what is mecasermin ?

Answer 12

recombinant form of human IGF1

only drug in the market has similar to IGF1

Question 13

when is mecaserin used?

Answer 13

severe primary igf-1 deficiency

hormone receptor mutation

patients with neutralizing antibodies

Question 14

what is the side effect of mecaserin?

Answer 14

IGF 1 has insulin like effects

it can induce HYPOGLYCEMIA so must be initiated at lower doses

Question 15

what is sermorelin ?

Answer 15

synthetic growth hormone releasing hormone ( GHRH )

Question 16

what are the uses of sermorelin?

Answer 16

idiopathic GH deficiency in children

GH deficiency secondary to Hypothalamus damage rather than pituitary abnormalities

( IN THIS CASE PITUITARY SOMATOTROPES CAPABLE OF SECRETING GH AND ARE FUNCTIONING )

Question 17

how and when sermorelin is administered?

Answer 17

subcutaneous injection

DAILY

Question 18

what is the effect of glucocorticoid on GH?

Answer 18

inhibit the effects of recombinant GH

so when patient is taking both long term glucocorticoids and rhGH ——> the glucocorticoid will inhibit the growth effect of GH —->GROWTH FAILURE

Question 19

what would compromise the final height of a patient ?

Answer 19

androgens , estrogens and thyroid hormones + anabolic steroids

these would accelerate epiphyseal closure of bones –> stopping the lengthening of the bones

Question 20

what is the example of GHIH?

Answer 20

somatostatin like drugs –> END WITH EOTIDE

octreotide –> synthetic somatostatin

Lanreotide aceate –> prolonged secretion

pasireotide –> higher affinity

Question 21

what are the uses of octreotide ?

Answer 21

acromegaly –> excessive GH

neoplastic diseases:

carcinoid syndrome

pituitary adenomas that secrete thyrotropin

tumors that produce vasoactive intestinal polypeptide

Question 22

how and when octreotide is administered ?

Answer 22

subcutaneously every 8 hours

long acting intramuscular formula given once monthly

oral formulation

Question 23

how is octreotide administered orally even though it is peptidal?

Answer 23

it is formulated with transient permeability enhancer which allows it to be absorbed easily

Question 24

what is lanreotide acetate?

Answer 24

prolonged release formulation of octreotide

given subcutaneous injection once every 4 weeks

Question 25

what is pasireotide?

Answer 25

somatostatin analog that has broader affinity for somatostatin receptors than octreotide and lanreotide this high affinity results in greater GH inhibition

Question 26

when is pasireotide used?

Answer 26

ocrtoetide / lanreotide resistant adenomas

Question 27

what are the pharmacokinetics/dynamics of Somatostatin analogs?

Answer 27

Transient GI disturbances are common but usually subside within the first 3 months of therapy Inhibit gallbladder contractility and decrease bile secretion ---> lead to development of biliary sludge and asymptomatic gallstones ---> Cholelithiasis Cholelithiasis ---> occur in patients treated for 12 month or longer ( it is only time related not age or gender related ) alter balance of hormones --> hypoglycemia / hyperglycemia GHIH May suppress pituitary release of TSH because GHIH inhibit both GH and TSH leading to decreased thyroid hormone secretion --> hypothyroidism --> Commonly with octreotide Sinus bradycardia, conduction abnormalities and arrhythmias --->commonly with octreotide and lanreotide

Question 28

what is administered with somatostatins to reduce the adverse effects?

Answer 28

insulin oral hypoglycemia agents beta blocker calcium channel blockers require careful dosage adjustment

Question 29

what is cabergoline?

Answer 29

dopamine agonists another example is bromocriptine

Question 30

what can dopamine agonists do GH?

Answer 30

reduce circulating levels of GH , IGF1, Prolactin

Question 31

when are dopamine agonists can be used?

Answer 31

treatment of person with elevated growth hormone and prolactin secretion

Question 32

what you should monitor when administering dopamine agonists?

Answer 32

visual disturbances, menstrual cycles ( cuz prolactin inhibit it ), sexual function ( men ) prolactin serum concentration every 3 to 4 weeks

Question 33

what is pegvisomant?

Answer 33

GH receptor antagonist

Question 34

what is the MOA of pegvisomant?

Answer 34

blocks the receptor and stops IGF1 and from binding to the receptor

Question 35

when is pegvisomant used?

Answer 35

acromegaly patients with Resistance to octreotide like pasireotide

Question 36

what are the non pharmacolgical treatments of acromegaly?

Answer 36

- transsphenoidal surgical resection of adenoma - radiation therapy