Women's Health Flashcards
First Phase: Follicular phase (proliferative phase)
- endometrium builds up d/t estrogen which leads to production of estradiol
- regulated by FSH which stimulates follicles to develop and mature
- egg released after about 14th day of menstrual cycle
- LH surges and leads to ovulation
- after ovulation, endometrium proliferates
Second Phase: Luteal phase
- progesterone produced by luteum and plays big part in this phase
- temp increases 1/2 to 1 degree farenheit
- ovum travels as a blastocyte via fallopian tube to uterus for implantation
- after implantation, hCG starts to be produced to help maintain the corpus luteum to support the ovum/zygote
Polymenorrhea
21 day cycle
oligomenorrhea
cycle >35 days
amenorrhea
cycle >180 days (6 months)
Menorrhagia
heavy flow
metrorrhagia aka menometrorrhagia
prolonged bleedings with no clear pattern
What are used in replacement therapy, contraception, and/or management of menopause
gonadal hormone made from cholesterol
estradiol
—most potent estrogen; secreted in the ovary by the premenopausal woman
estrone
metabolite of estradiol; 1/3 of the potency of Estradiol; primary estrogen in the postmenopausal woman; generated from conversion of androstenedione in the peripheral and
adipose tissues
estriol
another metabolite of Estradiol; much less potent than Estradiol; principal estrogen produced by the placenta
Conjugated Equine Estrogen
sulfate esters of Estrone + Equilin is a common oral estrogen used as
HRT [Premarin]
Synthetic estrogens—ethinyl estradio
undergoes less liver metabolism than naturally occurring estrogens, so can be safely used at low doses
SERMs
Nonsteroidal compounds that bind to estrogen receptors [have both estrogen and anti-estrogen effects]
-ex: tamoxifene and raloxifene
MOA of estrogens
-activated steroid-receptor complex interacts with nuclear chromatin to initiate
hormone specific RNA synthesis
- Used for postmenopausal hormone therapy, contraception, replacement in the
premenopausal patients who are deficient [hypogonadism, premature menopause,
surgical menopause
Postmenopausal Hormone Therapy
Used in vasomotor instability, vaginal atrophy
If the woman has a uterus, progestogen must be included to reduce the risk of
endometrial cancer
If the woman has had a hysterectomy, unopposed estrogen is used—progestins may have
negative effects on the lipid panel
ADE are less than in those using estrogens for contraception
Estradiol by patch or gel is also effective for postmenopausal symptoms
Risks of HRT—increased risk of CV events and breast cancer
Women with only GU symptoms are best treated with vaginal estrogens
Other uses for postmenopausal hormone therapy
Contraception
- Combination of estrogen and progestogen is used
Primary Hypogonadism - Estrogen that mimics natural cycle + progestogen to stimulate development of secondary sexual characteristics - Must be continued until after growth has been completed
Premature Menopause
- Estrogen + progestogen replacement is
used
Naturally Occurring Estrogens
Absorbed though the GI tract, skin & mucous membranes
Taken orally, estradiol is rapidly metabolized by the liver; micronized
estradiol is available and has better bioavailability
Synthetic Estrogen Analogs
Ethinyl estradiol, mestranol & estradiol valerate are well absorbed after oral
ingestion
These are fat soluble, they are stored in adipose tissues, from there they are slowly released
Synthetic estrogen analogs have prolonged action & are more potent than natural estrogens
Metabolism of estrogens
Estrogens are transported to the blood bound to albumin or SHBG;
bioavailability of oral estrogen is low [because of 1st pass metabolism]; to
reduce 1st pass effects—give the drug transdermally, intravaginally or by
injection
They are then hydroxylated in the liver to derivatives that are then
glucuronidated or sulfated
The parent drugs and the metabolites are excreted into the bile and are then
reabsorbed through the enterohepatic circulation; inactive products are
excreted in the urine
Adverse effects of estrogen
Nausea Breast tenderness Elevation of BP Elevation of triglycerides Peripheral edema Increased risk of VTE and MI Increased risk of breast and endometrial cancer [endometrial cancer risk reduced by concomitant use of a progestin]
Selective Estrogen Receptor Modulators
Estrogen related compounds that display selective agonism or antagonism for estrogen
receptors—depending on the target tissue
SERM examples
Tamoxifen Toremifene [Fareston] not prescribed in US Raloxifene [Evista] Clomiphene [Clomid] Ospemifene [Osphena]
How does tamoxifen, toremifene, and raloxifene work?
By compete with estrogen for binding to the estrogen receptor in the breast tissue
Raloxifene (Evista) works by…
Raloxifene also acts as an estrogen agonist in the bone, leading to decreased bone resorption, increased bone density and decreased vertebral fractures. Unlike
Tamoxifen and estrogen,
Raloxifene does not have appreciable estrogen receptor agonist activity in the endometrium [so no increased risk of endometrial cancer]
Raloxifene also lowers total and LDL cholesterols
Clomiphene works by…
Clomiphene acts as a partial estrogen agonist and interferes with the negative feedback of estrogens on the hypothalamus
These effects increase secretion of gonadotrophin releasing hormone and gonadotropins—stimulating ovulation
What is tamoxifen used for?
in—metastatic breast cancer; add on therapy after mastectomy or XRT for breast cancer; prevention of breast cancer in those at high risk
What is Raloxifene used for?
prevention of breast cancer in those at high risk; prevention and treatment
What is Clomiphene used for?
used for infertility from
anovulatory cycles
What is Ospemifene used for?
—treatment of dyspareunia from
menopause
Pharmacokinetics of SERMs
SERMs rapidly absorbed after PO administration
Tamoxifen—metabolized by CYP450 isoenzymes
Raloxifene—rapidly converted to glucuronide conjugates through 1st pass metabolism; undergoes enterohepatic cycling—main route is excretion through the bile into the feces
ADE of tamoxifen and toremifene
—hot flashes; nausea; endometrial hyperplasia and
malignancies have been reported with Tamoxifen
ADE of raloxifene
hot flashes and leg cramps; increased risk of DVT, PE and retinal vein
thrombosis; avoid use of Questran while taking Raloxifene
ADE of clomiphene
headache, nausea, vasomotor flushes, visual disturbances, ovarian
enlargement, increased risk of multiple births [these effects are dose related]
what is Progesterone
natural progestogen; produced in response to LH in women & by the testes in men; also produced by adrenal cortex in
both sexes
MOA of Progesterone
In women—progesterone promotes development of secretory endometrium that
accommodates implantation of newly forming embryo
High levels released during the luteal phase inhibit the production of gonadotropin and
prevent ovulation—if conception occurs, progesterone continues to be produced to
maintain the endometrium & reduce the uterine contractions
If conception does not occur, release of progesterone from corpus luteum stops—this decline causes menstruation to take place
Therapeutic uses of progesterone
Contraception
Treatment of hormone deficiency
Control of DUB (dysfunctional uterine bleeding), dysmenorrhea, endometriosis management and infertility
For contraception—they are combined with estrogens
Synthetic progestogens—progestin used in contraception are more stable to first pass
metabolism
- Desogestrel, Dienogest, Drospirenone, Levonorgestrel, Norethindrone, Norethindrone acetate,
Norgestimate, Norgestrel
- Medroxyprogesterone acetate injection [this agent is used orally as part of HRT]
Pharmacokinetics of progesterone
Micronized progesterone is rapidly absorbed after oral ingestion
Metabolized by liver; glucuronidated metabolite is excreted by the kidney
Oral medroxyprogesterone acetate has a ½ life of 30 days; when given IM or SC the ½ life is about 40-50 days and gives
contraceptive activity for approximately 90 days; other progestins have ½ lives of 1-
3 days allowing for once a day dosing
ADEs of progesterone
ADEs
- Headache
- Depression
- Weight gain
- Changes in libido
Progestins that are derived from 19- nortestosterone possess some androgenic
activity because of their similarity to
testosterone—can cause acne and hirsutism
Those that are less androgenic—norgestimate
and drospirenone, are preferred in women
with acne [can raise K+]
Antiprogestins
Progesterone antagonist with partial agonist activity
Use of this drug early in pregnancy usually in abortion due to
interference with the progesterone
Often combined with the prostaglandin analog Misoprostol [PO
or intravaginally] to induce contractions—uterine bleeding and
the possibility of incomplete abortion
Example of antiprogestin
Mifepristone [RU-486]
✹Progesterone antagonist with partial agonist activity
✹Use of this drug early in pregnancy usually in abortion due to
interference with the progesterone
✹Often combined with the prostaglandin analog Misoprostol [PO or intravaginally] to induce contractions—uterine bleeding and
the possibility of incomplete abortion
Major classes of contraceptives (COCs)
Combination on an estrogen & a progestin
Triphasic COC attempt to mimic the natural female cycle—most contain a constant dose
of estrogen with increasing doses of progestin given over 3 successive 7 day periods
Active pills are taken for 21-24 days, followed by 4-7 days of placebo, for a total regimen of 28 days—withdrawal bleeding occurs during the hormone free period
Extended cycle contraception [84 pills followed by 7 days of placebo] results in less
frequent withdrawal bleeding
Most common estrogen COC
ethinyl estradiol
Most common progestins im COCs
—norethindrone, norethindrone acetate, levonorgestrel, desogestrel, norgestimate and drosperidone
Contraceptive patches
Ethinyl Estradiol and Norelgestromin Patch is applied weekly for 3 weeks to abdomen, torso or buttocks 4th week no patch is worn Efficacy comparable to COCs in women weighing <90 kg Total estrogen exposure greater than with COCs
Contraceptive ring
Vaginal ring of Ethinyl Estradiol and
Etonogestrel
Ring left in place for 3 weeks, then left out
for r1 week
Efficacy, contraindications & ADEs similar
to COCs
Progestin Pills
Norethindrone—called “Mini Pill” Taken daily Less effective than COCs; they may produce irregular menstrual cycles Can be used while breast feeding, can be used in those intolerant to estrogen, those that smoke or those with contraindications to estrogens
Progestin Injections
Medroxyprogesterone acetate given IM or SC every 90 days ADE Weight gain Amenorrhea Bone loss/osteoporosis Return to fertility may be delayed for several months after discontinuation Drug should not be used for >2 years unless patient is unable to use other methods