progestogen Flashcards
what is progesterone
the most important progestogen
what is the most important progestogen
progesterone
what is progestogen
class of steroid hormones that bind to and activate the progesterone receptor
what is the site of progesterone release in females
- corpus luteum in 2nd part of menstrual cycle
- placenta (pregnant)
- small from adrenal gland
what is the site of progesterone release in males
testis and adrenal cortex
does progesterone bind to albumin
yes
does progesterone bind to SHBG
no
where is progesterone metabolized
in the liver
what pathway is progesterone in (mineralocorticoid, glucocorticoid or sex steroid)
mineralocorticoid actually!!!
what is the plasma half life of progesterone
5 mins actually
what are 3 main actions of progesterone in females
- preperation for ovum implantation
- negative feedback
- thermogenic effect
how do progesterone prepare for ovum implantation
- decrease estrogen endometrial proliferation
- grow endometrial blood vessels
- more viscous cervical mucus, less alkaline and less welcoming for sperm
what does progesterone do to estrogen-driven endometrial proliferation and how
decreases by stimulating differentiation, leading to the development of secretory endometrium
what does progesterone to do endometrial blood vessels
cause growth
what does progesterone to do cervical mucus (3)
makes it more viscous, less alkaline and less welcoming to sperm
what does progesterone to do negative feedback
reduces frequency of GnRH pulses
reduce gonadotrophin release from gonadotropes
what does progesterone to do GnRH pulses
reduces frequency of pulses from GnRH neurons
what does progesterone to do gonadotrophin release
reduce gonadotrophin release from gonadotropes
what does progesterone to do body temperature
increases it by 0.5 celcius
when does progesterone increase body temp
ovulating until the end of cycle
what is the mechanism of action of progesterone
progesterone receptors
what does progesterone do to male reproduction
no major effect
what does progesterone do to male mood
may cause aggression in rats towards infants
what are 3 therapeutic uses of progesterone
birth control, gynecological disorders, postmenopausal hormone replacement
how is progesterone used in birth control
either alone or with estrogen
how is progesterone used in gynecological disorders
dysmenorrhea and endometriosis
what is dysmenorrhea
painful cramps
how does progesterone help with dysmenorrhea
reduces estrogen induced contractions
how does progesterone help with endometriosis
oppose estrogen so less proliferation and bleeding and symptoms
how does progesterone help with postmenopausal hormone replacement
in combo with estrogen to prevent endometrial hyperplasia and reduce risk of endometrial carcinoma
what is the mechanism of action of antiprogesterone (mifepristone RU486)
competitive progesterone receptor antagonist
what happens if you administer antiprogesterone (mifepristone RU486) at early pregnancy
- blockage of progesterone receptor in uterus leads to detachment of blastocyst
- sensitize uterus to prostaglandins (contractions)
what does antiprogesterone (mifepristone RU486) sensitize the uterus to
prostaglandings
what does antiprogesterone (mifepristone RU486) do to ovulation (2 how)
inhibits
- blocks graffian follicle growth
- counteracts positive feedback action of estradiol on gonadotrophin release
what does antiprogesterone (mifepristone RU486) do to graffian follicle
inhibits growth
antiprogesterone (mifepristone RU486) gonadotrophin release
counteracts the positive feedback action of estradiol on gonadotrophin release
what does antiprogesterone (mifepristone RU486) do to secretory endometrium
impairs its development, discourages implantation
what is a main use for antiprogesterone (mifepristone RU486)
termination of early pregnancy
what happens with prostaglandins at the uterus
more contraction
what is antiprogesterone (mifepristone RU486) often given with and when and why
a prostaglandin analogue 48 hours later (induces contraction and labour)
how is antiprogesterone (mifepristone RU486) used as emergency contraception + how does it work
single low dose up to 120 hours after
inhibiting or delaying ovulation
what is in the combined oral contraceptive pill
estradiol and progestogen
what is a monophasic preperation
meaning there is the same hormone for each pill
what is a tri or biphasic preperation
2 or 3 types of pills with different estrogen: progestin ratio
what is the efficacy of combined pills
99%
what are 5 beneficial effects of combined pill
- decreased pregnancy and mother death
- decrease iron deficiency anemia + PMS
- less ovarian and endometrial cancer
- less dysmenorrhea or irregularity
- improved acne
why is there less ovarian and endometrial cancer with combined pill
less gonadotrophin release
why is there less acne with combined pill
inhibition of gonadotrophin release leads to reduction in androgen production
what does the combined pill do to LH and FSH secretion
decrease
what does decreased LH and FSH secretion from the combined pill cause
suppression of ovarian follicle development and prevention of ovulation
what does progestogen do to cervical mucous and what does this cause
makes it thick so sperm cant penetrate
what does progestogen do to endometrium and what does this cause
antiproliferative on endometrium to discourage implantation
what are 2 main untoward effects of combined pill
vascular disorders and cancer
what vascular disorders happen with combined pill
venous thrombosis, myocardial infarction, cerebrovascular disease
who has the highest risk of vascular disorders with combined pill
smokers women over 35 obese diabetic long term users
what cancers happen more with with combined pill
breast
does breast cancer happen more with with combined pill
yes
does cervical cancer happen more with with combined pill
no
what GI disorders can happen with combined pill
small increase risk of cholestatic jaundice, gallbladder disease and hepatic adenoma
what mental disorder can happen with combined pill
depression in 6%
what skin disorders can happen with combined pill
skin pigmentation (darker)
what can happen with combined pill to period
amenorrhea (if too much suppression)
what can happen with combined pill to weight
gain due to androgenic effect of synthetic progestogen
what can happen with combined pill to swelling
edema
what can happen with combined pill to vaginal infection
increase
what can happen with combined pill to head hurt
migraine wah
when is progestogen only pill the drug of choice
with severe dysmenorrhea (and when estrogen use is undesirable)
what are 3 disadvantages to progestogen only pill
must be taken daily
less reliable contraceptive
may cause irregular bleeding
how can progestogen only or combined be used for emergency contraception
both act by preventing or delating mid cycle LH surge (negative feedback mechanism) to suppress ovulation
what are selective progesterone receptor modulators
emergency contraception drugs
are progestogen only or combined OR selective progesterone receptor modulators more effective as emergency contraception
selective progesterone receptor modulators
how do selective progesterone receptor modulators work
block progesterone binding to receptors
what do selective progesterone receptor modulators do to follicle and how
delays maturation (cause they need progesterone receptors)
why is selective progesterone receptor modulators better than combined or prog only
because it can delay ovulation even on the day of the LH peak !! (thats too late for the other ones)
can selective progesterone receptor modulators delay ovulation on the same day as LH peak
yeff
can combined or prog only delay ovulation on the same day as LH peak
nope
what are analogs of gonadotrophin releasing hormone
GnRH super-agonists or antagonists (substitution of specific amino acids in GnRH)
what are benefits of GnRH analogs
- increase degradation resistance
- high GnRH receptor binding
- longer receptor occupancy
- more convenient routes of administration
how often is endogenous GnRH released and from where
60-90 mins from hypothalamus
what does continous high levels of GnRH cause
desensitization of pituitary GnRH receptors nd inhibition of gonadotrophin release
what does it mean to be a GnRH super agonist
very high GnRH receptor binding affinity
what is a therapeutic use of GnRH analogues
infertility in women
how do you treat infertility in women
pulsatile GnRH and anti-estrogen (Clomiphene)
or
exogenous gonadotrophins + GnRH agonist or antagonist
what happens when you use pulsatile GnRH and anti-estrogen (Clomiphene) together + why
more gonadotrophin secretion (Decrease negative feedback on gonadotropes) and stimulation of ovulation
what 2 things happen with exogenous gonadotrophin use for infertility
longer ovarian stimulation so increase # of mature follicles
what happens when you use continuous GnRH agonist or GnRH antagonist
less endogenous gonadotrophin secretion so less risk of premature endogenous LH surge (more mature follicles, increase fertility)
how do you do male contraception
continous GnRH agonist or antagonist in conjunction with testosterone
ia T alone or with GnRH more effective for contraception
together
what is good post partum contraceptive + why
GnRH analogues (because clots are v common after giving birth)
is GnRH anaogue safe for baby in milk
yes cause the analogue has no biological activity in milk
what are some other uses of GnRH anaglues
suppress hormone levels, like
- prostate cancer
- breast cancer
- endometriosis
- uterine fibroids
- hirsutism
- children with GnRH dependent precocious puberty