Anterior Pituitary Drugs Flashcards
What is the role of GH (somatropin) hormone?
Required for normal growth; targets bone, adipose, liver, muscle
What is the role of GHIH (somatostatin) hormone?
Binds to anterior pituitary GHRH receptors suppressing GH release, support GI motility
What is the role of ACTH (corticotropin) hormone?
Stimulates steroid biosynthesis; normal cortisol should be 20 ug/dL
What is the role of GnRH hormone?
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
What is the role of prolactin?
Stimulates and maintains lactation, decrease libido; inhibited by dopamine, stimulated by TRH
What is the use of Somatropin (synthetic GH)?
- Tx of GH deficiency or growth failure in children
- Indicated in Turner syndrome, Noonan syndrome, Prader-Willi syndrome
- Management of AIDS wasting syndrome (cachexia)
What is the MOA of Somatropin?
Synthetic GH
- Many effects mediated directly at its targets
- Stim liver to release insulin-like growth factors 1 and 2
What are the PK of Somatropin?
- SubQ or IM injection
- Half-life about 25 minutes
What are side effects of Somatropin?
Pain at injection site, edema, arthritis, myalgias, flu-like sx, increased risk of DM: insulin insensitivity
What are the contraindications of Somatropin?
Pediatric patients with closed epiphyses, diabetic retinopathy, obese pts w/ Prader Willi syndrome, increased ICP
What is the use of Octreotide?
- Tx of acromegaly
- Diarrhea/flushing ass w carcinoid tumors
- Tx of bleeding esophageal varicies
What is the MOA of Octreotide?
Synthetic GHIH analog
- Binds to GHRH and inhibits the release of GH, IGF 1, Insulin, glucagon, gastrin, 5-HT
What is the PK of Octreotide?
SubQ admin, every 4 weeks
- Half-life is longer than that of its natural compound, somatostatin
- DOA: 12hr-6wks
What are the side effects of Octreotide?
- Diarrhea, abdominal pain, flatulence, nausea, steatorrhea, bradycardia/conduction disturbances
- Gallbladder emptying delayed
What is the use of Pegvisomant?
Treatment of refractory acromegaly
What is the MOA of Pegvisomant?
Synthetic GH analog
- Antagonist at GH receptors, inhibits GH and IGF-1 release
What is the PK of Pegvisomant?
SubQ admin
What are the side effects of Pegvisomant?
Diarrhea
Nausea
Pain
Abnormal LFTs
What is the use of Corticotropin
- Dx tool for differentiating between primary and secondary adrenal insufficiency
- Infantile spasm
What is the MOA of Corticoptropin?
Binds to receptors on surface of adrenal cortex, activating G protein - coupled processes that stimulate cortisol and adrenaline release
What is the PK of corticotropin?
IM, SubQ, or intranasal admin because their peptidyl nature makes them susceptible to destruction by the proteolytic enzymes of the digestive tract
What are the side effects of Corticotropin?
- Short-term use usually well tolerated
- Long-term use: HTN, peripheral edema, hypokalemia, emotional disturbances, increased risk of infection (similar SE to steroids)
What is a synthetic ACTH analog used as a diagnosis tool of primary and secondary adrenal insufficiency?
Cosyntropin
What are the adverse effects of cosyntropin?
Excess glucocoritiocoid toxicities: HTN, peripheral edema, hypokalemia, osteoporosis
What is the MOA of Leuprolide (synthetic GnRH analog)?
Bind to GnRH receptors to either stimulate FSH/LH release or down-regulate GnRH receptors (causing suppression of FSH/LH)
What are the uses of Leuprolide?
Tx of prostate cancer, breast cancer, endometriosis, uterine fibroids, early puberty in transgender youth
Delay ovulation in IVF cycles
What is the PK of Leuprolide?
SubQ
Continuous or pulsatile depending on whether you want to increase or decrease gonadal hormone production
What are the side effects of Leuprolide in Women?
Hot flashes, sweating, decreased libido, depression, ovarian cysts
What are the side effects of Leuprolide in Men?
Bone pain, hot flashes, edema, gynecomastia, decreased libido
Leuprolide is contraindicated when
In pregnancy and breast feeding
What synthetic GnRH analogs work by suppressing the production of gonadotropins?
Goserelin
Nafarelin
Histrelin
What is the use of Goserelin?
Prostate and breast cancer
What is the use of Nafarelin?
Endometriosis and early puberty
What is the use of Histrelin?
Advanced prostate cancer
What is the use for Bromocriptine?
Tx of hyperprolactinemia
Pituitary microadenomas
Type 2 diabetes (theoretically)
Parkinson’s
What is the MOA of Bromocriptine?
Dopamine receptor agonist that inhibits prolactin secretion
What is the MOA Cabergoline?
Dopamine receptor agonist that inhibits prolactin secretion (higher affinity to D2 than D3)
What are the uses for Cabergoline?
Tx of hyperprolactinemia
Pituitary microadenomas
What are the side effects of Cabergoline and Bromocriptine?
HA, dizziness, psychosis, nausea
Cabergoline has lesser side effects compared to Bromocriptine
