Drugs that affect the pituitary and hypothalamic hormones

Question 1

Review the releasing factors or memorize for the following hormones-
– TSH
– ACTH
– LH and FSH
– GH
– Prolactin

Answer 1

– TRH (+)
– CRH (+)
– GnRH (+)
– GHRH (+), SRIH (‐), other (+)
– Dopamine (‐)

Question 2

does somatostatin inhibit or increase pituitary release of hormones?

Answer 2

inhibit

Question 3

IGF-1 is only used when?

Answer 3

in syndromes of GH resistance

Question 4

What are the side effects of GH therapy?

Answer 4

mostly in adults

• peripheral edema
• carpal tunnel
• impaired glucose tolerance
• hypothyroidism

Question 5

What are the side effects of GHRH?

Answer 5

injection site reactions an headaches

Question 6

What are 2 syndromes of GH excess? what are their origins?

Answer 6

1. Acromegaly (adult onset)
2. Gigantism (childhood onset)

• Origins
– GH‐secreting adenomas (~80% of cases)
– Enhanced pituitary function (~20% of cases)

Question 7

Why is it important for somatostatin agonists to be selective for receptor types 2 and 5?

Answer 7

This is important because other subtypes of
somatostatin receptors are present in the pancreas and
activation of these receptors results in the inhibition of
glucagon, insulin, and gastrin release.

Question 8

What is the incidence of gallstones in somatostatin agonist use?

Answer 8

20-30%

Question 9

how is pegvisomant able to block GH action?

Answer 9

Binds the receptor but does not allow dimerization

Question 10

T-F–Prolactin is structurally homologous to
growth hormone, but the prolactin receptor
is not structurally homologous to the growth
hormone receptor.

Answer 10

False- both structurally homologous

Question 11

What does prolactin stimulate? inhibit?

Answer 11

1. lactation

2. reproductive functions

Question 12

What is a very common cause of amenorrhea, galactorrhea, and female
infertility?

Answer 12

Hyperprolactinemia

Question 13

What inhibits the release of prolactin?

Answer 13

hypothalamic dopamine

Question 14

Vasopressin does what on V1 ? V2?

Answer 14

1. V1 receptors in vascular smooth muscle:
   vasoconstriction.
2. V2 receptors in renal tubule: increases
   resorption of water.

Question 15

When is vasopressin used?

Answer 15

Used as replacement therapy in diabetes insipidus

of pituitary origin

Question 16

Low Ca2+ or PTH leads to what?

Answer 16

skin/live/kidney creating more vitamin D and thus increasing Ca

Question 17

High Ca leads to what?

Answer 17

thyroid C cells releasing calcitonin and decreasing Ca

Question 18

T-F–glucocorticoids onGI tract decrease serum calcium and glucocorticoids on bone increase serum calcium?

Answer 18

true

Question 19

T-F–vitamin D is now associated with better prostate or breast health? how can it be administered?

Answer 19

1. True

2. Oral or IM

Question 20

What does calcitonin do?

Answer 20

hormone made in the C cells of
the thyroid. It inhibits bone resorption and
causes decreased serum calcium

Question 21

How is calcitonin preparations given?

Answer 21

subQ, IM, nasal spray

Question 22

What are bisphosphates taken up by? what does etidronate do? what do the amino bisphosphates do?

Answer 22

1. osteoclasts
2. retards the dissolution of
   hydroxyapatite
3. inhibitors of
   geranylgeranyl diphosphate synthase an enzyme
   involved in isoprenoid biosynthesis. This leads to
   an inhibition of bone resorption.

Question 23

What are the 2 classes of osteoporosis?

Answer 23

1. age-related, postmeopause

2. drug induced (glucocorticoids)

Question 24

How do we prevent and treat osteoporosis?

Answer 24

1. daily exercise
2. diet and Ca intake, vit D
3. prevent calcium mobilization from bone (bisphosphonates, calcitonin, raloxifene, estrogen/progestin combo post menopause)

Question 25

How is denosumab administered? PTH/teriparatide?

Answer 25

injection

injection

Question 26

What is the main difference between denosumab and PTH/teriparatide (forte)

Answer 26

the first stops osteoclasts, the 2nd stimulate`s osteoblasts

Question 27

What are the 4 causes of hypocalcemia?

Answer 27

1. Dietary calcium deficiency
2. Vitamin D deficiency (nutritional rickets)
3. Other forms of vitamin D deficiency or
   resistance (metabolic rickets, osteomalacia)
4. Hormonal imbalances (hypoparathyroidism,
   pseudohypoparathyroidism)

Question 28

What is vitamin D mainly used for?

Answer 28

increase Ca absorption with calcium salts

Question 29

What are the 4 causes of hypercalcemia?

Answer 29

1. Hyperparathyroidism
2. Ectopic PTH production
3. Vitamin D excess
4. Body immobilization