Contraceptives Flashcards
Estrogens
Estradiol, estriol, estrone
Progestin
Progesterone
Major site of synthesis
Ovarian granulosa cells
Corpus luteum
Estrogens Special Effects
- Reduced bone resorption
- Metabolic effect
- Pro-coagulatory effects
Progestins Special Effects
- Basal body temperature
* Endometrial and cervical secretion
Synthetic (and conjugated) compounds
Estrogens: ethinyl estradiol; mestranol
Progestins:
A. ester of progesterone
medroxyprogesterone acetate
B. 19-nortestosterone
norethindrone — moderate androgenic
norgestimate & levonorgestrel – low androgenic
Contraceptive Preparations (3 types)
Estrogen+progestin
Progestin Alone
Post-coital
Combined Contraceptives
Multiple mechanisms of action Prevent ovulation (Negative feedback on FSH and LH) Thickened cervical mucus Endometrial changes to prevent implantation
Lunelle
Estradiol cypionate + medroxyprogesterone acetate
Injection given every 28-33 days
50% of women experience withdrawal bleeding that begins 20-25 days after injection
15% may experience no bleeding at all
>99% effective
NuvaRing
Etonogestrel/Ethinyl estradiol A flexible ring about 2 inches in diameter that is inserted into the vagina Remains in the vagina for 3 weeks, then is removed for 1 week 99% effective
Ortho Evra
ethinyl estradiol and norelgestromin
A transdermal patch that delivers E + P
Worn continuously for 7 days before being replaced with new patch
Regimen followed for 3 weeks followed by a patch- free week
99% effective; Less effective in women weighing over 198 lbs.
Patch risk: three times higher blood clots due to the 60%more estrogen than a normal pill
Continuous estrogen/progestin combination pills
No scheduled menstrual bleeding
Increased risk of unrecognized pregnancy
Estrogen Adverse effects
GI disturbances Weight gain Migraine headache Fluid retention Breast tenderness Increased blood clots Endometrial cancer (for HRT)
Progestins Adverse effects
Breakthrough bleeding
Mild depression
Weight gain
Yasmin®, Yaz® or Ocella®
synthetic progestin drospirenone, plus ethinylestradiol
drospirenone can elevate the body’s potassium levels and lead to hyperkalemia, thus serious and potentially fatal heart problems
Progestin alone therapy
Mechanisms of action: prevent ovulation, thickening of cervical mucus, endometrial changes, 97-98% effective
Therapeutic indication: Estrogens contradicted or poorly tolerated
Postcoital contraception
Ethinyl estradiol/levonorgestrel (Preven)
Plan B levonorgestrel
Mechanisms of action (not clear)
Delays or prevents ovulation
Endometrial changes that prevent implantation
Not effective if already pregnant
1st dose within 72 hrs, 2nd dose 12 hrs later
Clomiphene (Clomid)
Fertility drug Mechanism of action: estrogen receptor antagonist Inhibits negative feedback effects on hypothalamus and anterior pituitary Induces ovulation
Mifepristone (RU-486, Mifeprex)
Contragestation
competitive antagonist of progesterone and glucocorticoid receptors
Uses: Medical abortion (early pregnancy)
Administered after implantation; leads to endometrial shedding
Selective estrogen receptor modulators (SERMs)
Mimic the effects of estrogen in some organs but act as antagonists in others
Tamoxifen (Nolvadex)
Estrogen antagonist in breast tissue, inhibits proliferation of breast cancer
Raloxifene (Evista)
Estrogen antagonist in breast and uterin, agonist in bone
- -prevent postmenopausal osteoporosis
- -reduce the risk of invasive breast cancer in postmenopausal women
Femara (Letrozole)
aromatase inhibitor, reduces estrogen production
First line treatment for breast cancer with or without positive response to estrogen
Hormonal replacement therapy
Primary Hypogonadism
Postmenopausal Hormonal Therapy based on estrogen
Alleviation of hormone-withdrawal symptoms
hot flashes, night sweats, etc.
Prevention of osteoporosis
Estrogen decreases bone resorption
