Hypothalamus & Pituitary Flashcards

1
Q

What hormones does the anterior pituitary release

A
FSH, LH, ACTH, TSH, PRL, GH
Those hormones (EXCEPT PRL) go on to stimulate production of hormones from peripheral endocrine glands, liver, or other tissues
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2
Q

What hormones does the posterior pituitary release

A
Oxytocin, ADH/vasopressin 
Those hormones (along with PRL) act directly on tissues
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3
Q

What hormones are released from the hypothalamus and what are their funcitons

A
  • GHRH: rarely used as GH/GHRH sufficiency test
  • TRH: can dx TRH/TSH deficiency
  • CRH: rarely used to dx Cushing
  • GnRH: treats infertility caused by deficiency, stops gonad fxn in precocious puberty, men w/ prostate cancer, women undergoing ART, and ovarian suppression for women w/ gyno d/o
  • Dopamine: Tx hyperprolactinemia
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4
Q

What is Growth Hormone’s primary target organ hormone

A

IGF-1

target organs are liver, bone, muscle, kidney, etc.

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5
Q

What provocative pharm GH stimulation tests can you do for GH deficiency

A
Insulin induced hypoglycemia 
Clonidine 
L-dopa
Arginine 
Glucagon
GHRH 
-You expect GH to increase. If GH increases <10 in 2 hours, you have a GH deficiency
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6
Q

What will you likely see along with GH deficiency

A

reduced IGF-1
hypoglycemia
hypothyroidism
loss of other pituitary hormones

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7
Q

Who should get GH treatment

A

kids with idiopathic short stature (<2.25 SD below mean height for age)
subnormal growth for age
delayed bone age
low serum IGF-1
*>50% of kids with GH deficiency secrete normal GH and IGF1 as adults

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8
Q

What are treatments for GH deficiency

A

Somatotropin (Genotropin)
Mecasermin (Increlex)
*Needed for normal growth to regulate lipid and carb metabolism and LBM ; also to regulate production of IGF-1 in peripheral tissues
-CAN switch formulations during Tx w/o negative impacting growth trajectory

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9
Q

Child indications for GH treatment

A

Short stature (turner, Noonan, or Prader-Willi syndrome)
FTT (2/2 chronic renal failure)
small for gestational age
*Will only add appx 1.5-3 inches if w/ idiopathic short stature

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10
Q

Indications for GH treatment in adulthood

A

GH deficiency (will improve metabolism, LBM, and well being)
Wasting 2/2 HIV (increase LBM, weight, endurance)
Short bowel syndrome (improve GI fxn)

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11
Q

ADE of Somatotropin (genotropin)

A

Kids: pseudotumor cerebri (HA, blurred vision, diplopia, n/v), slipped capital femoral epiphysis, scoliosis progression, hyperglycemia
Adults: rarely peripheral edema, myalgia, arthralgia

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12
Q

If a child is taking Somatotropin (genotropin) always monitor

A

concurrent deficiency of other ant pit hormones

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13
Q

Drug interactions when taking Somatotropin (genotropin) include

A

glucocorticoids (inhibit growth promoting effects)
Other hormones; androgens, estrogens, thyroid hormones, anabolic steroids (speed up epiphyseal closure, compromising final height)

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14
Q

What is Mecasermin

A

Recombinant human IGF-1 for kids with growth failure that DON’T respond to GH therapy and are deficient in IGF-1

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15
Q

ADE of Mecasermin include

A

Hypoglycemia (eat before taking dose!)
Tonsillar/adenoidal hypertrophy
Lymphoid hypertrophy
Coarse facial features

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16
Q

GH secreting pituitary adenomas cause

A

Acromegaly in adults

Gigantism in kids and teens

17
Q

TOC for acromegaly is

A

Pituitary transsphenoidal microsurgery

18
Q

What diagnostic test is preferred for excess GH

A

OGTT;
postprandial hyperglycemia inhibits secretion of GH for 1-2 hours
if you give an oral glucose load, GH should decrease

19
Q

Secondary testing for GH excess is

A

Serum IGF; GH stimulates IGF-1 production

20
Q

What pharm treatment options are available for GH excess

A
Dopamine agonists (bromocriptine, cabergoline) 
Somatostatin analogs (Octreotide, Lanreotide, Pasireotide)- more effective than dop. ag
GH receptor antagonist (Pegvisomant)
21
Q

Pegvisomant is highly effective at

A

normalizing IGF-1 in 97% in one year, 60% in 5 years

22
Q

Dopamine agonists are used mainly to treat

A

Acromegaly;
they normally cause an increase in GH production. In Acromegaly, they cause a paradoxical DECREASE in GH production
*They also normalize IGF-1 concentrations (cabergoline>bromocriptine)
*Cabergoline can be added to a somatostatin analog

23
Q

ADE of Dopamine Agonists are

A

CNS: HA, light headed, dizziness, nervous, fatigue
GI: nausea, abd pain, diarrhea
Resp: nasal congestion, thick bronchial secretions

24
Q

How do somatostatin analogs (octreotide) work

A

inhibit release of GH, glucagon, insulin, and gastrin
Tx acromegaly and other neuroendocrine tumors
*long acting forms available; 4-6 wk duration

25
ADE of Somatostatin analogs (octreotide) are
gallstones (inhibit release of CCK) cardiac conduction abn HTN Abnormalities in glucose metabolism (decrease insulin, inhibits IGF-1) Subclinical hypothyroid (TSH high, T4 normal)
26
How does Pegvisomant work
Inhibits IGF-1 production blocks physiologic effect of GH on tissues Treats acromegaly in pts who failed to achieve normal IGF-1 with other Tx
27
ADE of Pegvisomant include
Increased liver enzymes edema nausea diarrhea
28
What are Raloxifene and Tamoxifen used for
Selective estrogen receptor modulators Treat persistent acromegaly in men and post-menopausal women with Hx of breast cancer Reduces and normalizes IGF-1 levels (does not reduce GH) *Serum testosterone in men increases
29
What are prolactinomas
benign prolactin secreting pituitary tumors
30
What can cause hyperprolactinemia
Prolactinomas or Medications (increase PRL or antagonize Dopamine)
31
What are some drugs that cause hyperprolactinemia
Increase PRL: methyldopa, reserpine; estrogen, benzos, TCA, MAOI, SSRI, opioids, cocaine Dopamine antag: antipsychotics, phenothiazine, metoclopramide Verapamil
32
How do you treat hyperprolactinemia
``` #1: Dopamine agonist (better than surgery!) Radiation therapy (W/ surgery to shrink tumor and decrease PRL) TSS (if refractory or cant tolerate meds; if very large tumor) ```
33
What are the dopamine agonists
Cabergoline (pref), bromocriptine | Inhibit release of PRL (Dop inhibits PRL)
34
ADE of bromocriptine are
Infertility! HA, dizzy, fatigue, diarrhea, nausea, abd pain | *give with food*
35
ADE of cabergoline are
decrease in BP; constipation, n/v, fatigue, anxiety, depression (rare) HA, dizzy
36
What is Panhypopituitarism
complete (or partial) loss of pituitary fxn; involves ant and post pit -ACTH/ Gonadotropin/ GH deficiency, hypothyroidism, hyperprolactinemia
37
How do you treat panhypopituitarism
Replace glucocorticoids, thyroid hormones, and sex steroids +/- recombinant GH **Tx is lifelong w/ constant monitoring!