Hormone Contraception Flashcards
Describe the Mechanism of estrogen and progestin-induced gene transcription.
Both of these hormones will bind two their receptors in the nucleus of a target cell. Binding causes a conformational change leading to the dissociation of deactivating-heat shock proteins. Afterwards, the homodimerized receptors are free to bind DNA or other transcription factors.
What are the clinical uses of estrogens?
HRT of primary hypogonadism - given at 11-13 y/o and progestin follows first uterine bleed
Postmenopausal HRT - reduces hot flashes, fractures, and urogenital atrophy
Suppression of ovarian function in hirsutism and acne
Contraception and dysmenorrhea
What are the clinical uses of progestins?
Postmenopausal HRT and contraception
Describe the MOA of hormonal contraceptives
Prevent ovulation via feedback inhibition of the hypothalamic-pituitary axis.
Note: In combination, progestins and estrogens are more successful at suppression of LH and FSH and ovulation than either alone.
Describe the MOA of progestin-only contraceptives
Block ovulation in only 60-80% of cycles
Effectiveness - thickening of cervical mucus and endometrial alterations that impair implantation
What are the non-contraceptive benefits of oral contraceptives?
Reduced risk of epithelial ovarian and endometrial carcinoma
Reduced ectopic pregnancy and benign breast disease
Reduced Dysmenorrhea, hirsutism, and acne
What are the mild ADRs of oral contraceptives?
Nausea, mastalgia, breakthrough bleeding, edema, and migraines (indication to discontinue)
What are the moderate ADRs of oral contraceptives?
Breakthrough bleeding (avoided in combination therapies)
Androgenic effects (avoided with higher estrogen and anti-androgenic progestins)
What are the severe ADRs of oral contraceptives?
Vascular disease - thromboembolism (estrogens), myocardial infarction and CVA (elevated risk in smokers)
GI disease - cholestati jaundice and hepatic AD
Depression
Slightly increased risk of breast cancer
What are CIs for the use of estrogen-containing contraceptives?
Smokers > 35 y/o Cardiovascular disease Migraines Incomplete epiphysial closure Estrogen-dependent neoplasms
What are the CIs for the use of progestin-only contraceptives?
liver disease and breast cancer
Describe the androgenic and estrogenic profiles of progestins
Progestins vary in their estrogenic and androgenic potencies:
More androgenic activity (e.g., L-Norgestrel, Norethindrone) leads to acne, hirsutism, weight gain, etc.
Progestins with lower (Norgestimate) or anti-androgenic (Drospirenone) potency actually treat acne
What are the different metabolic effects of L-Norgestrel?
Androgenic, anti-estrogenic, and anabolic
What are the different metabolic effects of Norethindrone?
Androgenic, anti-estrogenic, and anabolic
What are the different metabolic effects of Drospirenone?
Anti-androgenic
Rank the methods of contraception (Oral, transdermal, vaginal ring, injections, IUDs, and implants) with respect to failure rate.
Oral > transdermal > vaginal ring > injections > IUDs > implants
Which oral contraceptives allow rapid return to fertility?
Oral, transdermal, vaginal ring, IUDs, and implantations
Note: Injections do not
Rank the methods of contraception (Oral, transdermal, vaginal ring, injections, IUDs, and implants) with respect to duration of effectivity.
IUD > Implant > Injection > vaginal ring > transdermal patch, and pills
Describe injectable progestin-only contraceptive
Medroxyprogesterone acetate
Injected intramuscularly every 3 months
The return of fertility can be delayed for 6-18 months after the last injection in some patients
Describe IUD, progestin-only contraceptive
L-norgestrel
Effective for 5-7 years
Describe the implantable progestin-only contraceptive
Etonogestrel
Placed under the skin of the upper arm and is effective for 3 years
Bleeding abnormalities are common
Describe the transdermal combo contraceptive
Ethinyl estradiol and norelgestromin
A new patch is applied each week for three weeks, followed by one patch-free week
More frequent breast discomfort, dysmenorrhea, nausea, vomiting, and skin irritation
Descibe the vaginal ring combo contraceptive
Ethinyl estradiol and etonogestrel
The ring is inserted and left in place for 3 weeks followed by one ring-free week
What are the risks and benefits of estrogen-only HRT?
Decreased osteoporosis
Increased thromboembolism and ischemic stroke
What are the risks and benefits of estrogen-progestin HRT?
Decreased osteoporosis and colorectal cancer
Increased breast cancer, MI, thromboembolism, and CVA
What is the MOA of tamoxifen and toremifene?
Partial competitive agonist inhibitor of ER
What are the uses of tamoxife and toremifene?
ER (+) breast cancer and chemoprevention of breast cancer
What are the risks and benefits of tamoxifen and toremifene?
Reduced risk of osteoporosis and atherosclerosis
Slightly increased risk of endometrial cancer
What is the MOA of Raloxifene?
Agonistic to ER in lipids and bone
Antagonistic at endometrium and breast
What are the clinical uses of raloxifene?
Prevention of post-menopausal osteoporosis and chemoprevention of breast cancer
What is the MOA and use of Mifepristone?
MOA - Progesterone receptor antagonist
Use - terminate early pregnancy and emergency contraceptive
Note: used with misoprostol (synthetic PGE-1)
What is the MOA and use of levonorgestrel
MOA - progesterone receptor agonist; unknown how emergency contraception is implemented
Use - Plan B; CAN’T reverse an established pregnancy
What is the MOA of Ulipristal Acetate?
MOA - similar to levonorgestrel, but longer duration of efficacy
Use - contraception, may interfere with established pregnancy
