Pharm Flashcards
Pathway of hypothalamus to signal lactation
dopamine from hypothalamus -> suppresses prolactin
Estrogen stimulates pituitary to release prolactin and breast lactates
Pathway of hypothalamus to signal estrogen and progesterone secretion
GnRH from hypothalamus -> FSH and LH from anterior pituitary -> ovaries secrete estrogen and progesterone
Negative feedback loop for GnRH and FSH/LH secretion
ovarian hormones: progesterone, estrogen, inhibins
opioid/endorphins
Positive feedback effects of estrogen/estradiol
Both positive and negative feedback on GnRH
at low/moderate levels… inhibits GnRH, LH, and FSH
at high levels… stimulates LH (“surge”)
also promotes endorphin secretion to increase “opioid tone”
More rapid pulse frequencies of GnRH secretion (1 pulse per hour) preferentially stimulate ____ secretion, whereas slower frequencies (1 pulse per 3 hours) favor ____ secretion.
LH
FSH
Conditions that can cause defects in GnRH pulse production
anorexia or malnutrition severe stress extreme weight loss prolonged physical exertion hyperprolactinema or lactation states
Physiological results of GnRH production defects
failure of follicles to develop
no estradiol secretion
secondary amenorrhea
role of FSH
recruit and growth of immature follicles; starts follicular phase of ovarian cycle
role of LH
triggers ovulation and development of corpus luteum
FSH rise is brought about by ________’s influence on slowing down GnRH pulsatility.
progesterone
Risk of estrogen deficiency
heart disease (atherosclerosis d/t HDL decrease)
osteoporosis
depression
IBS, bloating (water and Na retention)
Benefits of estrogen
development and maintenance of female reproductive organs, secondary sex characteristics, and breasts
promotes pregnancy - stimulates endometrium growth, vaginal lubrication, thickens vaginal wall, increases uterine growth
location of aromatase enzymes
liver
most dominant estrogen form lost during menopause or ovarian failure? most dominant in menstruating women?
estrone (E1)
estrodial (E2) = estrogen
MOA aromatase inhibitors
decreases estrogen
hCG produced by ______ upon implantation.
placenta
Progesterone functions
make endometrium ideal for implantation - decrease contractility, decrease maternal immune response
inhibits lactation during pregnancy; falls following delivery
What causes increased thickness of endometrial tissue in prep for pregnancy?
increase in estrogen (proliferative phase) and progesterone (secretory phase)
4 main groups of estrogen preparations for hormone replacement therapy
Human natural estrogens (17 beta-estradiol)
Nonhuman natural estrogens (horse urine)
synthetic estrogen analogs (eg ethinyl estradiol in Nuva ring and transdermal patch)
plant-based estrogens (phytoestrogens)
Estrogen replacement benefits
contraception, relief of vasomotor symptoms (eg, hot flashes and night sweats), relief of vulvovaginal atrophy, improvement or prevention of osteoporosis
cardioprotective???
ADRs of estrogen replacement therapy
common: nausea, breast tenderness, HA, dizziness
Breast cancer, DVT, PE
Do not give estrogen alone to what patients? Why?
patients with uterus
increased risk of endometrial cancer
Activity of 1st generation progestin agents
non-selective; affinity for estrogen, androgen, and progesterone receptors
Activity of 2nd generation progestin agents
affinity for progesterone and androgen receptors
NO estrogen effect
Progestin agents with only progestational activity
4th generation
Can progesterone replacement alone work as contraceptive?
yes like in Minipill but not as well as estrogen
ADRs of progestin agents
acne, increased appetite and weight gain, fatigue, HTN, depression
Why are estrogens used as contraceptive?
negative feedback loop prevents FSH release; prevents ovulation
Why are progestins +/- estrogens used as contraceptive?
inhibits LH surge for ovulation
tricks ovary into thinking it has already released egg
Efficacy of combined oral contraceptives with perfect use?
99%
Most commonly used form of estrogen in oral contraceptives?
ethinyl estradiol
How are biphasic or triphasic formulations of contraceptive different than monophasic?
monophasic: consistent amount of estrogen and progestin in each active tablet
bi/triphasic: vary the dose of estrogen, progestin, or both throughout cycle to better mimic the natural menstrual cycle
When is contraceptive pack of pills started?
first day of menses
How can patients skip their period? How often can this be done?
immediately start a new pack of pills at the beginning of week 4 instead of taking the placebo pills or having the no pill week.
Encourage patients to have at least one period every three months.