Anterior Pituitary Drugs

Question 1

What is the role of GH (somatropin) hormone?

Answer 1

Required for normal growth; targets bone, adipose, liver, muscle

Question 2

What is the role of GHIH (somatostatin) hormone?

Answer 2

Binds to anterior pituitary GHRH receptors suppressing GH release, support GI motility

Question 3

What is the role of ACTH (corticotropin) hormone?

Answer 3

Stimulates steroid biosynthesis; normal cortisol should be 20 ug/dL

Question 4

What is the role of GnRH hormone?

Answer 4

Binds to anterior pituitary receptors, stimulates FSH and LH release; pulsatile secretion essential for gonadotropin release, continuous secretion results in down regulatio of GnRH receptors and support of gonadotropin release

Question 5

What is the role of prolactin?

Answer 5

Stimulates and maintains lactation, decrease libido; inhibited by dopamine, stimulated by TRH

Question 6

What is the use of Somatropin (synthetic GH)?

Answer 6

• Tx of GH deficiency or growth failure in children
• Indicated in Turner syndrome, Noonan syndrome, Prader-Willi syndrome
• Management of AIDS wasting syndrome (cachexia)

Question 7

What is the MOA of Somatropin?

Answer 7

Synthetic GH
- Many effects mediated directly at its targets
- Stim liver to release insulin-like growth factors 1 and 2

Question 8

What are the PK of Somatropin?

Answer 8

• SubQ or IM injection
• Half-life about 25 minutes

Question 9

What are side effects of Somatropin?

Answer 9

Pain at injection site, edema, arthritis, myalgias, flu-like sx, increased risk of DM: insulin insensitivity

Question 10

What are the contraindications of Somatropin?

Answer 10

Pediatric patients with closed epiphyses, diabetic retinopathy, obese pts w/ Prader Willi syndrome, increased ICP

Question 11

What is the use of Octreotide?

Answer 11

• Tx of acromegaly
• Diarrhea/flushing ass w carcinoid tumors
• Tx of bleeding esophageal varicies

Question 12

What is the MOA of Octreotide?

Answer 12

Synthetic GHIH analog
- Binds to GHRH and inhibits the release of GH, IGF 1, Insulin, glucagon, gastrin, 5-HT

Question 13

What is the PK of Octreotide?

Answer 13

SubQ admin, every 4 weeks
- Half-life is longer than that of its natural compound, somatostatin
- DOA: 12hr-6wks

Question 14

What are the side effects of Octreotide?

Answer 14

• Diarrhea, abdominal pain, flatulence, nausea, steatorrhea, bradycardia/conduction disturbances
• Gallbladder emptying delayed

Question 15

What is the use of Pegvisomant?

Answer 15

Treatment of refractory acromegaly

Question 16

What is the MOA of Pegvisomant?

Answer 16

Synthetic GH analog
- Antagonist at GH receptors, inhibits GH and IGF-1 release

Question 17

What is the PK of Pegvisomant?

Answer 17

SubQ admin

Question 18

What are the side effects of Pegvisomant?

Answer 18

Diarrhea
Nausea
Pain
Abnormal LFTs

Question 19

What is the use of Corticotropin

Answer 19

• Dx tool for differentiating between primary and secondary adrenal insufficiency
• Infantile spasm

Question 20

What is the MOA of Corticoptropin?

Answer 20

Binds to receptors on surface of adrenal cortex, activating G protein - coupled processes that stimulate cortisol and adrenaline release

Question 21

What is the PK of corticotropin?

Answer 21

IM, SubQ, or intranasal admin because their peptidyl nature makes them susceptible to destruction by the proteolytic enzymes of the digestive tract

Question 22

What are the side effects of Corticotropin?

Answer 22

• Short-term use usually well tolerated
• Long-term use: HTN, peripheral edema, hypokalemia, emotional disturbances, increased risk of infection (similar SE to steroids)

Question 23

What is a synthetic ACTH analog used as a diagnosis tool of primary and secondary adrenal insufficiency?

Answer 23

Cosyntropin

Question 24

What are the adverse effects of cosyntropin?

Answer 24

Excess glucocoritiocoid toxicities: HTN, peripheral edema, hypokalemia, osteoporosis

Question 25

What is the MOA of Leuprolide (synthetic GnRH analog)?

Answer 25

Bind to GnRH receptors to either stimulate FSH/LH release or down-regulate GnRH receptors (causing suppression of FSH/LH)

Question 26

What are the uses of Leuprolide?

Answer 26

Tx of prostate cancer, breast cancer, endometriosis, uterine fibroids, early puberty in transgender youth Delay ovulation in IVF cycles

Question 27

What is the PK of Leuprolide?

Answer 27

SubQ Continuous or pulsatile depending on whether you want to increase or decrease gonadal hormone production

Question 28

What are the side effects of Leuprolide in Women?

Answer 28

Hot flashes, sweating, decreased libido, depression, ovarian cysts

Question 29

What are the side effects of Leuprolide in Men?

Answer 29

Bone pain, hot flashes, edema, gynecomastia, decreased libido

Question 30

Leuprolide is contraindicated when

Answer 30

In pregnancy and breast feeding

Question 31

What synthetic GnRH analogs work by suppressing the production of gonadotropins?

Answer 31

Goserelin Nafarelin Histrelin

Question 32

What is the use of Goserelin?

Answer 32

Prostate and breast cancer

Question 33

What is the use of Nafarelin?

Answer 33

Endometriosis and early puberty

Question 34

What is the use of Histrelin?

Answer 34

Advanced prostate cancer

Question 35

What is the use for Bromocriptine?

Answer 35

Tx of hyperprolactinemia Pituitary microadenomas Type 2 diabetes (theoretically) Parkinson's

Question 36

What is the MOA of Bromocriptine?

Answer 36

Dopamine receptor agonist that inhibits prolactin secretion

Question 37

What is the MOA Cabergoline?

Answer 37

Dopamine receptor agonist that inhibits prolactin secretion (higher affinity to D2 than D3)

Question 38

What are the uses for Cabergoline?

Answer 38

Tx of hyperprolactinemia Pituitary microadenomas

Question 39

What are the side effects of Cabergoline and Bromocriptine?

Answer 39

HA, dizziness, psychosis, nausea Cabergoline has lesser side effects compared to Bromocriptine