Contraception Flashcards

1
Q

When does pregnancy begin?

A
  • Pregnancy begins at IMPLANTATION of zygote to endometrial wall (NOT FERTILIZATION OF OOCYTE)
  • ## Demonstrated by +hCG
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2
Q

Steps needed for pregnancy (potential mechanisms for preventing pregnancy)

A
  1. Production & Maturation of gametes: (Prevent by blocking FSH)
  2. Ovulation of oocyte & passage through Fallopian tubes: (block LH surge, or cut Fallopian tubes)
  3. Ejaculation of Sperm: (Vasectomy: cutting Vasa Deferentia)
  4. Fertilization: (Barrier methods)
  5. Implantation: (Alter uterine lining)
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3
Q

Window of Peak Fertility

A
  • Days 10 to 17 (assuming ovulation is on day 14)
  • Luteal phase is consistently 14 days
  • Peak fertility window is determined by Follicular phase
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4
Q

Surgical Methods of Contraception

A
  • NOT REVERSIBLE
  1. Tubal ligation: cut & cauterize Fallopian tubes
  2. Transcervical sterilization: Insertion of Fallopian tube coils to scar uterine lining
  3. Vasectomy: Cut & cauterize Vasa Differentia
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5
Q

Immediately Reversible methods of contraception

A
  1. Copper IUD
  2. Barrier Methods
  3. Natural family planning
  • Combination E/P: may take 3-6 months to reverse
  • Longer acting hormonal methods: up to 6 months to reverse
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6
Q

Contraception methods with <10% Failure Rate

A
  • E/P pill, patch, ring

- DMPA

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7
Q

Contraception methods with <1% Failure Rate

A
  1. Copper IUD
  2. LNG-IUD
  3. Progesterone implant
  4. Tubal Ligation
  5. Vasectomy
  6. Transcervical sterilization
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8
Q

Short-acting vs. Long-acting

A
  • How often you have to renew the method

Short-acting: up to every 3 months
Long-acting: once every 3 months or longer

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9
Q

Progesterone Only: Delivery Methods

A
  1. Progesterone Pill (“Mini” Pills): Least reliable; indicated for breastfeeding women for which estrogen is poorly tolerated/contraindicated); requires taking at same time everyday
  2. Depot Medroxyprogesterone Acetate Injection (DMPA): < 1% failure
  3. LNG-IUD: <1% failure; best compliance
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10
Q

Progestins

A
  1. Progesterone
  2. Norethindrone
  3. (Levo) Norgestrel (LNG)
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11
Q

Progesterone

A
  • Natural progestin
  • precursor to estrogen
  • produced in ovaries by corpus luteum; production stimulated by LH surge, or by hCG during pregnancy

ANDROGENIC: main reason for side effects

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12
Q

Estranes: 19-Nortestosterone-like compounds

A
  • Synthetic progestin (2nd generation)
  • Contains C17 ethinyl group: DECREASES HEPATIC METABOLISM; INCREASES HALF-LIFE
  • still has androgenic side effect activity
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13
Q

Gonanes: 19-Nor 13-ethyl compounds

A
  • 3rd generation synthetics
  • DECREASED ANDROGENIC ACTIVITY
  • ALSO Contains C17 ethinyl group: DECREASES HEPATIC METABOLISM; INCREASES HALF-LIFE
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14
Q

Mechanism of Progestins:

- secondary benefits

A

Activation of Progesterone Receptors (PRs)

  • PR-A: Inhibits
  • PR-B: Stimulatory properties

Physiologic doses (during menses):

  • Supports Luteal phase, generating secretory endometrium
  • Elevates temp at onset of ovulation
  • suppresses mentruation/uterine contractions during pregnancy
  • Decreases frequency of GnRH pulses –> results in negative feedback of LH production

Pharmacological doses (contraceptive):

  • Endometrial regression: impairs implantation
  • Creates thick cervical mucus, decreasing sperm penetration
  • Prevents ovulation by decreasing frequency of GnRH pulses

Secondary benefits:

  • Lighten or completely stop menses (but 1/3 have irregular spotting)
  • LNG-IUD is FDA approved to treat MENORRHAGIA (very heavy menses)
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15
Q

Contraindications of Progestins

A
  1. Pregnancy
  2. History of Breast Cancer
  3. Undiagnosed Vaginal Bleeding
  4. Active Thromboembolic Disease
  5. Abnormal Liver Function
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16
Q

Toxicities of Progestin-Only Preps

A
  1. Irregular mentrual bleeding
  2. Increased BP: use with caution in HTN patient
  3. Raise LDL, but decrease HDL
  4. For long term therapy: delayed return to ovulatory function
  5. Androgenic effects: Acne, Hirsutism
  6. Weight gain: 15-20 lbs/year
  7. Increased risk of breast cancer when used with estrogen for Hormonal Replacement Therapy
17
Q

Estrogens

A
  1. Estradiol: really short half life (minutes)
  2. Ethinyl Estradiol: No first pass effects, thereby having longer half life (13-27 hours)

Indications:

  1. Estrogen deficiency: Hormone Replacement Therapy
  2. Prevents/retards Osteporosis
  3. Contraception
  4. Hirsutism: suppresses ovarian androgen production
  5. Amenorrhea
  6. Dysfunctional uterine bleeding
  7. Dysmenorrhea
  • Before ovulation: produced in FOLLICLE by theca & granulosa cells
  • After ovulation: produced in CORPUS LUTEUM by Luteinized granulosa & theca cells
18
Q

Pharmacokinetics of Estrogens

A
  • Rapid biotransformation, half-life only lasting minutes (Ethinyl Estradiol avoids first pass effect, lengthening half life to 13-27 hours)
  • undergoes ENTEROHEPATIC CYCLING to maintain levels of estrogen
  • Contraindicated with Antibiotics: Antibiotics decrease microflora, reducing enterohepatic cycling
  • Rifampin Abx (induces hepatic enzymes): potential chemical/drug interactions that induce clearance of estrogen
19
Q

Effects of Estrogen

A
  1. Decreases rate of bone resorption by increasing osteoclast apoptosis and decreasing PTH –> reduces osteoporosis
  2. Net favorable effects on plasma lipids
  3. Decreases bile acid secretion –> increases risk for gallstones
  4. Induces Blood Coagulation: increased risk of clot formation
  5. Increases progesterone receptor synthesis: synergistic effect
20
Q

Combo E/P Delivery Methods

A
  1. Pill: Monophasic (fixed doses of E/P); Multiphasic (Dose of Progesterone varies throughout); Continuous use (Quarterly menses)
  2. Patch: replace weekly
  3. Nuvaring: Inserted in vagina for 3 weeks
21
Q

Combo E/P Mech of action

A

Progesterone:

  • decreases GnRH pulses –> suppresses LH
  • Thick cervical mucus: inhibits travel of sperm
  • Atrophic endometrium

Estrogen:

  • Inhibits FSH secretion
  • Altered transport of Fallopian tube

Secondary Benefits:

  • improved acne
  • regulation/control of menstrual cycle
  • lighter & shorter periods: prevent anemia
  • Improved cramps: dysmenorrhea
  • Protection against osteopenia
  • decreased risk of ovarian and endometrial cancer
22
Q

Combo E/P Contraindications

A
  1. Cardiovascular disease: Stroke, HTN
  2. Thromboembolic disease/hypercoag
  3. Abnormal liver function
  4. History of breast cancer in that patient (family history of breast cancer is NOT a contraindication)
  5. Smoker > 35 yo
  6. Migraine with neurological aura
  7. Vaginal bleeding
  8. Pregnancy or breast feeding
  9. Fibroids, Diabetes, Severe Headaches
23
Q

Combo E/P Major Toxicities

A
  1. Thromboembolism/MI: esp in older patients or smokers
  2. Gallbladder disease: b/c decreased secretion of bile acids
  3. Cause Migraines w/o aura: due to incresed risk of stroke
  4. No increased risk of breast cancer for E/P contraception use (risk is increased only at doses for HRT) (Estrogen may be protective against ovarian/endometrium cancer)
  5. HTN
  6. Delayed Return to Fertility
24
Q

Barrier Contraceptives

A

Methods: Prevent fertilization by stopping sperm from entering uterus

  1. Male condom: physical barrier
  2. Female condom: may be inserted up to 8 hours before intercourse
  3. Diaphragm: fits against vaginal wall near base of cervix; is a chemical barrier (used with spermicide)
  4. Cervical cap (physical barrier)/sponge (chemical barrier): fits snugly over cervix; high failure rate
  5. Spermicide

Effectiveness: 15-20% failure rate/year
Convenience: Short acting

Contraindications: allergy to latex or spermicide

Side effects: diaphragm may increase risk of UTI

Secondary benefits:

  • STI protection
  • male condom: Prevent premature ejaculation
  • female condom: clitoral stimulation from external ring
25
Copper IUD
Mech: Primarily inhibits fertilizations by reducing sperm motility & viability; secondarily inhibits implantation - as effective as surgical methods; recommended for adolescent women - very long acting Can be used as EC: maintains very high effectiveness over 120 hour window after sex Contraindications: - current STI (gonorrhea or chlamydia) - unexplained uterine bleeding - Larger deforming fibroids - Wilson's disease or copper allergy NOT Contraindicated: - Young: it's recommended for adolescents - Nulliparous: won't affect future pregnancy - Multiple sex partners/History of STIs: no increased risk of PID IUD side effects: - uterine perforation - Expulsion - cramping after insertion - PID risk: during first 30 days after insertion - HEAVY MENSES
26
Natural Family Planning (Fertility Awareness)
Method: use calendar, and avoid intercourse during window of fertility; no sex on days 8-19 of cycle - cervical mucus thins and becomes slippery at at ovulation - basal body temp rises during ovulation Effectiveness: low (25% failure rate/year) Contraindications: - Irregular menses - Anything that interferes with cervical mucus (infection, douching, breastfeeding, perimenopause)
27
Emergency Contraception Types
1. Levonorgestrel 2. Ulipristal 3. Copper IUD - Window: w/in 120 hours after sex - contraindication: known pregnancy
28
Levonorgestrel
- high dose progesterone - delays ovulation - consists of several combo E/P pills to get high dose Progesterone - 95% effective during first 24 hrs; effectiveness decreases after 72 hrs; less effective if obese - Contraindication: pregnancy: won't work
29
Ulipristal
- Progesterone receptor modulator: Progesterone agonist/antagonist - delays ovulation & prevents implantation - May be able to cause early abortion, so rule out pregnancy first - Maintains very high effectiveness to 120 hours Contraindication: pregnancy: may cause early abortion
30
Clomiphene
- Estrogen receptor antagonist: acts as a weak estrogen / competitive inhibitor - Use: treat anovulatory women: decreases estrogen inhibition in hypothalamus --> increases GnRH secretion, FSH/LH to stimulation ovulation Toxicities: - multiple births - ovarian hyperstimulation - ovarian cysts/cancer
31
Tamoxifen
- Selective Estrogen Receptor Modulator (SERM): Tissue dependent effects: - Agonist: bone, endometrium, coagulation, lipids - Antagonist: breast, recruits co-repressors - use: treatment of advanced breast cancer, or prevention in high-risk women - Requires CYP2D6 for activation Toxicities: - hot flashes - *increased risk for DVT and pulmonary embolism - *Increased risk of endometrial cancer - increased risk of cataracts - nausea
32
Raloxifene
- Selective Estrogen Receptor Modulator (SERM): Tissue dependent effects - agonist: Bone, lipids (NOT breast/endometrium) - Use: treatment of osteoporosis and breast cancer prevention in high risk women - Less risk of endometrial cancer compared to TAM - does not alleviate vasomotor symptoms of menopause Toxicities: (all red) - hot flashes - leg cramps - increased risk of DVT and pulmonary embolism
33
Letrozole
- Aromatase (CYP19A) inhibitor: prevents generation of estrogen from adrenal androgens in periphery --> decreases estrogen synthesis Use: in advanced breast cancer when anti-estrogen has failed; extended remissions longer than TAM Toxicities: - ARTHRALGIAS - Hot flashes - fatigue