Week 11: Estrogens and Anti-Estrogens Flashcards
Effects of estrogen
- increases bone density
- normal skin and blood vessel structure
- affects lipid levels
- reduces bowel motility
- enhances coagulability of blood
- causes edema because of its action on the RAAS
- maintains stability of the thermoregulatory center
How does estrogen work to prevent pregnancy?
- suppresses LH which manipulates the hormones and prevents ovulation
Explain monophasic, biphasic, and triphasic estrogen treatment
Monophasic - same hormone dose every day - given to help even out hormone levels
Biphasic - hormone dose changes every 14 days
Triphasic - hormone dose changes every 7 days (mimics a normal cycle)
Estrogens cautions/CIs
- over age 35 and a smoker
- uncontrolled HTN
- venous thrombosis
- any GYN cancer
- hx of CVA
- cirrhosis
- migrane w/ aura
- ischemic heart disease or risk factors
- pregnancy
Considerations when prescribing estrogen
- start at the lowest estrogen dose while maintaining cycle control
- Ethinyl estradiol 20-35mg (20mg - low dose; > 30mg - high dose)
- estrogen only products are contraindicated in women with an intact uterus
Contraceptive start methods
First Day Start
- pills started on the first day of the menstrual cycle
- no backup method needed
Sunday Start
- first pill taken on the Sunday following the start of menses
- backup method for first 7 days
Quick or ‘Same Day’ start
- first pill taken on the day of the office visit
- backup method for first 7 days
Advantages of oral contraception (combined estrogen & progestorone)
- highly effective
- rapidly reversible
- regulates menstrual bleeding
- decreased menstrual blood loss and dysmenorrhea
- reduction in risk of ovarian and endometrial CA
Topical patch (Ortho Evra)
- applied weekly for 3 weeks and 1 week off
- no 1st pass effect
- increased failure rate for women weighing more than 198 pounds
Vaginal Ring (NuvaRing)
- placed in vagina and left in place for 3 weeks, and then left off for 1 week
- better cycle control and decreased breakthrough bleeding compared to OC
- lower systemic exposure to estrogen
- if out for more than 3 hours-use backup method for 7 days
Drug interactions with COC (combined oral contraceptives)
- metabolism is increased by any drug that increased liver microsomal enzyme activity: includes anticonvulsants - decreased COC effects
- Rifampin is the only antibiotic proven to reduce serum EE and progestin levels
- Griseofulvin (antifungal) - associated with contraceptive failure (limited data)
Indications for estrogen treatment in menopause
- vasomotor symptoms - systemic treatment (oral, transdermal, topical gels)
- genitourinary symptoms (vaginal dryness, burning, vulvar itching/burning, recurrent UTIs - localized/vaginal treatment (intravaginal creams, tablets, rings)
- *consider type of estrogen and route of administration as well as need for progestin**
Types of Estrogen products
- Conjugated equine estrogens (CEEs) - estrone - derived from pregnant mare urine
- Synthetic conjugated estrogens - phytoestrogens - plant based (soy, yams)
- Micronized 17-beta estradiol - bioidentical to premenopausal estrogen
- Esterified estrogen - conjugated estrogen
- Ethinyl estradiol (EE) - more potent than others - used in very low doses (5mcg - unless symptoms are severe) - titrate up if symptoms are not relieved by low dose
Vaginal estrogen treatment in Menopause
Local treatment
- used in low doses for vaginal atrophy
- no recommended to use higher dose in those who need GU symptom treatment only
Estrogen ADR (in menopause)
- breast soreness
- H/A
- Elevated blood pressure
- exacerbation of diabetes - hyperglycemia
- cholestasis
- thromboembolic event - blood clotting
- endometrial hyperplasia can develop as a result of estrogen being prescribed in women without an intact uterus
Contraindications to menopausal hormone therapy (MHT)
- hx of breast cancer
- CAD
- Venous thromboembolic event (DVT/PE)
- Stroke/TIA
- Active liver dz
- unexplained vaginal bleeding
- high risk endometrial cancer
- if pt has hx of migraine w/ aura - transdermal formulation is preferred
