pituitary d/o & ED Flashcards
name the two hormones secreted by POST pit
Oxytocin and ADH
negative feedback loop
causes a decrease in function
more common feedback
positive feedback loop
increases a function till outcome is reached or stimulus is removed
ex. oxytocin production
how is oxytocin production controlled
positive feedback mechanism
causes milk release or labor contractions which signals more production of oxytocin and continues till delivery or feeding is done
what symptom is caused by excess prolactin hormone
galactorrhea/amenorrhea
hypogonadism in men & women
what is galactorrhea
milky nipple discharge unrelated to normal milk production
condition of excess ACTH
Cushing Disease
condition of excess TSH w/ normal T4
hyperthyrotropinemia
condition of excess LH/FSH
hypergonadotropinemia
general rule of what causes hyperprolactinemia
anything that disrupts the pituitary stalk and blocks dopamine inhibition
what is the most common pituitary tumor
prolactinoma
what controls prolactin secretion
dopamine. presence of dopamine inhibits the secretion of prolactin
causes of hyperprolactinemia
physiologic (stress, pregnancy, etc)
pharmacologic (anti-depressants, H2 blockers, opiods, etc)
pathologic (prolactinoma, renal failure, etc)
drugs that induce hyperprolactinemia
anti depressant/anti-psychotics
estrogen
H2 blockers
what is a prolactinoma
most common functioning adenoma; can cause hyperprolactinemia
mass effect of prolactinomas result in… (2 things)
visual changes (bitemporal hemianopsia)
headache
treatment for prolactinoma
dopamine agonist
surgery (transphenoidal resection)
XRT (radiation)
what are the two dopamine agonists that can be used to treat prolactinomas? what are their ADR?
bromocriptine & cabergoline
ADR- nausea, lightheadedness, congestion
what labs are needed if a pituitary tumor is suspected?
1 Prolactin
TSH, LH, GH, FSH
Estrogen, pregnancy test
what are normal prolactin levels
men <20, women <25 pregnant is up to 400
what would be seen on an MRI if theres pituitary tumor
stellar mass
acromegaly vs gigantism
acromegaly– growth plates closed so they are not super tall
gigantism– before epiphyses close so they get very tall
etiology of gigantism and acromegaly
GH secreting adenoma
sx of GH excess
increased growth of distal parts (spade like hands, phalangeal bony overgrowth)
macroglossia, enlarged sinus/frontal bossing (lantern jaw)
organomegaly (liver, spleen, kidneys)
prominent nasolabial folds
diagnostics if suspecting excess GH
serum GH
IGF-1
MRI
what must you do before collecting serum GH
give insulin first– glucose suppresses GH levels so give it clear up glucose and see true GH levels
tx for excess GH
1 surgery (transphoenoidal resection)
#2 pharm: (dopaminergic drug or GH blocker- octreotide or pegvisomant)
#3 XRT
ADR of surgical or XRT
hypopituitarism
effect of cortisol on hypothalamus & pituitary
inhibitory effects via negative feedback
reduces CRH from hypothalamus & ACTH from pituitary
what is Sheehan’s syndrome
hypopituitarism d/t postpartum hemorrhage causing pituitary gland necrosis
classic signs of sheehans syndrome
fatigue
inability to lactacte
low BP
irregular or amenorrhea
thinning of vaginal lining
loss of pubic hair & wt gain
sequalae of sheehans syndrome
adrenal insufficiency
hypothyroidism
amenorrhea
DI
inability to breast-feed
diagnostics for sheehans syndrome
serum pituitary hormone levels (would be low)
MRI/CT
how is sheehans syndrome treated?
lifelong HRT
hormones incharge of testosterone & spermatogenesis
LH–> Leydig cells–> testosterone
FSH–> Sertoli cells–> Spermatogenesis/Inhibin B
negative feedback
first test to check for male reproductive potential
semen analysis
2-3 separate counts at least 2-4 weeks apart
normal semen analysis
volume: 2-6 mL
sperm conc: 20-100 mill/mL
>50% motility w/ forward progression
>12% normal forms
<1 mill/mL WBC
factors contributing to male infertility
varicocele (cause 44% of time)– bag of worms; too hot
trauma– torsion, tumor
infections, high fever/heat
drugs– chemotherapy, ETOH, marijuana, tobacco, steroids, pesticides
Kleinfelters syndrome
47 XXY
low testosterone, reduced muscle mass, facial & body hair
breast enlargement
little or no sperm
Kleinfelters syndrome
47 XXY
low testosterone, reduced muscle mass, facial & body hair
breast enlargement
little or no sperm
diagnostics for kleinfelters syndrome
genetic test
treatment for kleinfelter syndrome
testosterone replacement & fertility treatment
____% of infertility amongst couple is traced back to the male
30%
workup for infertility
semen analysis & ovulation
mechanism of erections
increased arterial flow to penis
relaxation of smooth muscle of trabeculae whereby blood is shunted into corpora cavernosa
if a young male presents with ED, it could be a hallmark sign for CV dz, what should you do to check?
lipid panel
A1C
they have risk of major cardiac even in 7-10 yrs
Organic vs Psychogenic ED
organic: gradual, have RF, consistent dysfx, no sleep erections, can have orgasms
psychogenic: sudden, No RF, situational & varying dysfx, no orgasm, have sleep erections
RF for ED
obesity
HTN, DM
smoking
dyslipidemia
sedentary
age
ED tx options
1 PDE-5 inhibitors
intracavernosal injections
intraurethral suppository (can use w/ PDE-5)
vacuum
penile prosthesis (highest patient & partner satisfaction)
MOA of PDE5 inhibitors
potentiate effects of cGMP to prolong erections and increase sexual satisfaction
ADR of PDE5 inhibitors
blue tinges in vision & muscle pain (most common)
HA, nausea
Rhinitis
flushing
dyspepsia
if you’re going to prescribe PDE5i what should you make sure of?
that pt isn’t taking alpha blocker– risk of hypotension from double smooth muscle dilation
that pt isnt taking nitrate– absolute contraindication
list the four PDEi meds (-afil)
sildenafil (viagra)
vardenafil
tadalafil– longer half life & enhanced erectile fx (the weekender)
avanafil– shorter onset of action
what is Alprostadil
a prostaglandin E1 analog; vasodilator
penile injection that increases cAMP
what is hypogonadism and how do you test for it?
low testosterone
#1 measure total testosterone
bioavailable testosterone if needed
“total” testosterone vs bioavailable testosterone
Total: free T + albumin bound T + sex hormone binding globulin (SHBG) bound T
bioavailable: free T + albumin bound T
sx of hypogonadism (not signs)
decreased libido, energy & muscle mass
increased body fat
cognitive changes & depressed mood
Signs of hypogonadism
truncal obesity, anemia, decreased bone density
Tx for hypogonadism
testosterone
gel & patch- daily; gel has risk of transference
IM q 3 wks
SQ pellets q 3 months
nasal
when would you not want to give testosterone
male of reproductive age who wants to have kids
